Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Eyepieces

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | (show all)
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Pentax XW versus Delos, an informal comparison
      #6034323 - 08/19/13 10:57 AM

I had recently the chance to compare the performance of several Delos eyepieces with that of Pentax XW EPs. The Deloi i looked through (and kept) are the 4.5, 6, 8, 12, 14. I traded my Pentax 7mm to have more versatility with 6 and 8mm EPs, not because i was unsatisfied with the Pentax 7mm. I bought the Delos 14 to try it and compare it to the Pentax 14 XW as some have issues with the XW, which is not my case.

These comparison were made on three telescopes. Keep in mind that i only use small aperture scopes and not monster dobs: a 4 inch f/7 refractor, a 8 inch SCT and a 12 inch f/5 dob. Some have reported differences between the Deloi and other minimal glass eyepieces and Ethoi using big dobs, which is not my case. These comparisons were done on several nights of average to good seeing with good transparency from the city and from a dark site. They are informal and non systematic. I just want to share my first impressions. I am not an eyepiece expert as Bill Paolini or Philip Creed, so this thread is more of what i saw and my personnal impression.

The short story : i think Televue has hit an homerun with the Delos eyepiece series. We were in need of a wider choice of focal lengths in the area of EPs offering 68 to 72 degrees of FOV with good eye relief. It is always good to have a little bit of competition and the Pentax XW were almost alone with these characteristics. Very comfortable to use, wide views, immersive and having a neutral tone, i think Televue has managed to produce a line of high quality EPs as good as the Pentax XW, which by itself was not a small task.

I will not go into a detailed comparison between all the EPs since i found that the Delos 4,5, 6, 8, 12 (i did not have a Delos 10 in my hands) performed optically and ergonomically equivalently to the Pentax XW 7 and 10mm. So the Delos 4.5-12 were very sharp on and off-axis on all my scopes, including my dob with a paracorr, except for some FC coming from my SCT possibly in the Delos 12mm. Compared to the Pentax EPs i own, it was a little bit more difficult to hold the exit pupil with the Delos than the Pentax. But lets be honest, i have been using the Pentax EPs for over a year, perhaps i just need a little bit of practice with the Deloi. The 20mm of eye relief in both EP lines is very comfortable with my glasses on and the adjustable eyecup and housing is very easy to use in both lines.

Then i tried the 14mm. Many complain about the FC with the 14 and 20 Pentax XW. Personally, i do not have any issue with these eyepieces with my refractor as there is no FC visible with these EP with that refractor. Paradoxically, i did notice a very slight degree of FC with the Delos 14 with that scope, but i suspect it comes from the scope itself as there is not FC using the Delos 14 on my f/5 dob without a paracorr. So in the chapter of FC, on my refractor, both the Pentax and Delos performed equally. With the SCT, there was FC with both EPs, in the outer 5-7% for the Pentax and less than that with the Delos. Part of that comes from the SCT for sure, but there was more with the Pentax. Personally the difference is not relevant for me, but that may be different depending on your obsession of looking at the field stop. And that may vary significantly between observers. I am 55 but when i focus a star in the outer half of the FOV, i really can focus on most of the FOV without problem even with the Pentax 14. So again, i would rate these EPs similarly in my SCT.

The story was very different with the dob. Without a paracorr, there was a lot of FC with the 14 and 20 Pentax XW. So much, that i would not use these EPs without a paracorr in a fast dob. With the Delos 14, i started seeing what seemed to me to be coma without using a paracorr coming from the scope most probably, at the outer 5% (or less) of the FOV. On the moon, i noticed loosing details in craters near the edge along the terminator. Again i suspect this comes from my mirror more than the eyepiece as i had the same problem with well corrected EPs in my dob. Something i had encountered with the 20T5, 24 pan, 16T5, 26T5 and panoptic 35. I can manage FC but hate coma!! Thus, i am always using a paracorr and would use one with the Delos 14 anyway. But the Delos 14 could be used in a fast dob without a paracorr. How did the Pentax 14 and Delos 14 mm compare in the fast dob but this time with a paracorr : both beautifully. Fantastic EPs, very immersive, excellent contrast and pinpoint stars from centre to edge. The only difference, one is lighter than the other.

Now came the evaluation of one of the potential problem with the Delos 14 : it requires more infocus than the other Deloi. Quite true, but not a problem with my scopes : just a couple of turns required with the SCT. The same with the refractor (an inch perhaps??). Really not an issue (especially from someone who used a focal reducer with his SCT : then you really need to refocus!!). Nothing annoying about the Delos. Just that it will not be parafocal with the other Delos. But i am used to that since in the past, i owned EPs from different companies that were not parafocal anyway.

I feared of using the Delos 14 in my dob. Would i have enough in focus?? I had changed the stock focuser on that scope with a low profile moonlite focuser. Without the paracorr, and with the paracorr, i could reach focus without problem. Interestingly, i continue to use a Pentax 10mm, and the focus is reached with that EP between the Delos 12 and Delos 14. So it is not that bad after all. But i could see that it could be a problem with some scopes. If you want all your Delos 14 to be ± parafocal with the other Deloi, then you will need to purchase an adapter that will cost $50.

What are my conclusions :

1) in the FL range of 12mm and below, both lines seem to be equivalent (i have not tested the 5mm Pentax and the 3.5 Delos). I would choose depending on the FL needed and on price. The advantage of the Pentax is that they can be obtained on the used market which is rarer for the Delos. But the Delos offer a wider range of choice which is interesting if you have more than one scope with different f ratios and FL.
2) For a 14mm EP, if you are one annoyed by FC and do not want to use a paracorr, then the Delos 14 is for you. If you use a paracorr with your dob, both a equivalent and i would have a hard time to chose. If you use a refractor, just try before you buy. Both may be equivalent. For a SCT, those who obsess over looking at the field stop should get a Delos. But you can be very happy with the Pentax otherwise.
3) There is no clear winner between these EP lines. I think the clear winner here is the amateur astronomer community : more choice and possibly some competition on price.
4) But it think there could be a clear looser with the advent of the Delos : the nagler T6 line. I looked at clusters with my 12 inch dob on Friday evening, comparing the Pentax with the Delos. Because of bad conditions in the last year, i had not looked at clusters that much in the last year. And it struck me : stars were full of colors with the Delos and Pentax, much more then when i was using T6s. I had the series of T6 from 7 to 13 before. The clusters were dull in terms of color with the T6, colors that were completely revealed with the Delos (and Pentax). This is something i had missed using the nagler T6 because they do not offer a neutral tone as the Delos does, at least to my eye. After this experience with the Delos, i will not get back to the T6. I like too much clusters and it was a revelation to me to see stars with the colors they should have.

I hope this helps if you are looking to purchase some of the Delos EPs. Notice that i have no idea how the Delos 17.5 performs.

Now i am done buying EPs. I thought i was done after purchasing the Pentax, but the Delos are just as good and offered more possibility in terms of FL, so i combined both lines of EPs in my EP case, and they live very well together.

Edited by coutleef (08/19/13 02:00 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6034366 - 08/19/13 11:21 AM

"Now i am done buying EPs."


Post Extras: Print Post   Remind Me!   Notify Moderator  
NHRob
Post Laureate
*****

Reged: 08/27/04

Loc: New Hampshire
Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6034440 - 08/19/13 12:02 PM Attachment (56 downloads)

Quote:

"Now i am done buying EPs."




Post Extras: Print Post   Remind Me!   Notify Moderator  
Lew Zealand
Pooh-Bah
*****

Reged: 06/28/04

Loc: Pasadena, CA
Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6034443 - 08/19/13 12:04 PM

Quote:

"Now i am done buying EPs."





While everyone is different, I think it's possible to be "done" buying EPs. Now, I'm not saying for sure or anything but it's possible. I have 50+ EPs (a ballpark guess, maybe I should count 'em or something), and I would buy a new EP or 3 at PATS each year but even though that didn't happen this year, I didn't have anything I wanted to buy. Yes, yes there are things I *could* buy but nothing I *wanted* to buy. Which is surprising as I have no Delos or Pentax or 100° EPs and all of those have good pricing right now. But here's the kicker:
I brought 3 new telescopes into the stable since buying my last EP.

Perhaps I've turned the EP corner, maybe I've been knocked on the head one too many times by the kids, could be sunspots.

But wait. François wrote:

"4) But it think there could be a clear looser with the advent of the Delos : the nagler T6 line. I looked at clusters with my 12 inch dob on Friday evening, comparing the Pentax with the Delos. Because of bad conditions in the last year, i had not looked at clusters that much in the last year. And it struck me : stars were full of colors with the Delos and Pentax, much more then when i was using T6s."

The last 2 EPs I bought were the 3.5 and 5mm Nagler T6s. Delos, you say, hmmm? On sale, you say, hmmm...


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: NHRob]
      #6034449 - 08/19/13 12:07 PM

OK guys,

in one year from now, we will look at my sig and compare the EPs i am using now and those that i will use then. i do not think they will be different.

i wont buy new ones, unless they come out with a pentax xw or Delos 24mm.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6034502 - 08/19/13 12:37 PM

Quote:

The short story : i think Televue has hit an homerun with the Delos eyepiece series.




Absolutely. If we are to believe the marketing, these were Ethos derivations therefore Ethos had to come first. But this should have been the eyepiece that TeleVue introduced 6 years ago.

Quote:

1) in the FL range of 12mm and below, both lines seem to be equivalent (i have not tested the 5mm Pentax and the 3.5 Delos).




I just picked up the 5XW, looking forward to putting it through it's paces. I will have to barlow a Delos to get equal focal lengths. Hardly fair to the Delos, but I'll do it anyway out of curiosity.

Quote:

4) But it think there could be a clear looser with the advent of the Delos : the nagler T6 line.




Interesting observation. The only T6 I have owned was the 13 Nagler, and it didn't knock my socks off. It didn't stay in my collection long.

Quote:

Now i am done buying EPs.




Until the Nagler Type7's and Panoptic Type 2's come out of course.


Post Extras: Print Post   Remind Me!   Notify Moderator  
mgwhittle
Pooh-Bah
*****

Reged: 08/24/11

Loc: Chattanooga, TN
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6034546 - 08/19/13 01:01 PM

Excellent write up! First rate, enjoyed reading it.

Quote:

And it struck me : stars were full of colors with the Delos and Pentax, much more then when i was using T6s. I had the series of T6 from 7 to 13 before. The clusters were dull in terms of color with the T6, colors that were completely revealed with the Delos (and Pentax). This is something i had missed using the nagler T6 because they do not offer a neutral tone as the Delos does, at least to my eye. After this experience with the Delos, i will not get back to the T6. I like too much clusters and it was a revelation to me to see stars with the colors they should have.




This was also a shock to me when I started using my Delos. If you think the colors aren't visible in the T6, try the Explore Scientific eyepieces. They are absolutely monotone compared to the Delos.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: mgwhittle]
      #6034569 - 08/19/13 01:15 PM

This is not exactly related to the OP, but I wanted to add my 2 cents here regarding the transmission of a 14mm Delos vs a 14mm ES 100.

I compared the two on NGC-6946 in Cepheus, which is extremely faint where I go observe in around 5.2 mag skies. In the 14mm Delos, the brightness of NGC-6946 was only slightly brighter than seeing it in my 14mm ES 100 degree eyepiece. I went back and forth quite a bit.

PS: This observation was done right after the 14mm ES 100 was launched from 6 feet in the air landing on rocks and dirt below, LOL. True story.



Post Extras: Print Post   Remind Me!   Notify Moderator  
BillP
Postmaster
*****

Reged: 11/26/06

Loc: Vienna, VA
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6034585 - 08/19/13 01:25 PM

François,

Great report The extra in-focus for the 14 and 17mm Delos is documented on the TV Epp Specifications page. Those two are not parafocal with the rest of the line and require approx 1/2 inch more in-travel than the others. The vividness of colors in stars you noticed with the T6 line compared to the XW/Delos is also something I have seen as well.

Overall great review. Getting past the optical and into the ergonomics/mechanicals, what was your impression of the mechanical eye guard differences between the XW and Delos? Did one fare better than the other after extended use, or more of 6/one, half dozen of the other?


Post Extras: Print Post   Remind Me!   Notify Moderator  
REC
Post Laureate
*****

Reged: 10/20/10

Loc: NC
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6034640 - 08/19/13 02:08 PM

The 13t6, really, you didn't like it too much?? I use it all the time in my scopes and like the lightness and compactness of it. Works really well in my 80ED for medium power, but never looked through the Delos or Pentax though.

Bob


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: Scanning4Comets]
      #6034643 - 08/19/13 02:09 PM

Quote:

This is not exactly related to the OP, but I wanted to add my 2 cents here regarding the transmission of a 14mm Delos vs a 14mm ES 100.

I compared the two on NGC-6946 in Cepheus, which is extremely faint where I go observe in around 5.2 mag skies. In the 14mm Delos, the brightness of NGC-6946 was only slightly brighter than seeing it in my 14mm ES 100 degree eyepiece. I went back and forth quite a bit.

PS: This observation was done right after the 14mm ES 100 was launched from 6 feet in the air landing on rocks and dirt below, LOL. True story.






See, you thought we were kidding when we told you it was a morter shell......


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: BillP]
      #6034667 - 08/19/13 02:22 PM

Quote:

François,

Great report The extra in-focus for the 14 and 17mm Delos is documented on the TV Epp Specifications page. Those two are not parafocal with the rest of the line and require approx 1/2 inch more in-travel than the others. The vividness of colors in stars you noticed with the T6 line compared to the XW/Delos is also something I have seen as well.

Overall great review. Getting past the optical and into the ergonomics/mechanicals, what was your impression of the mechanical eye guard differences between the XW and Delos? Did one fare better than the other after extended use, or more of 6/one, half dozen of the other?




thanks for the kind words. i view with glasses on so they all have the mechanical eyegard down. i think i would find both systems pleasant to work with. at first i did not understand how the delos worked but understood it after a couple of minutes ( i am not the engineer-type) while the pentax system was easy immediately. frankly i think the delos system is cleaver.

it is very relaxing to view with these EPs: as you once described like an eye massage. maybe a bit more with the pentax but that is related possibly to my longer experience with them


Post Extras: Print Post   Remind Me!   Notify Moderator  
mgwhittle
Pooh-Bah
*****

Reged: 08/24/11

Loc: Chattanooga, TN
Re: Pentax XW versus Delos, an informal comparison new [Re: REC]
      #6034681 - 08/19/13 02:29 PM

Quote:

The 13t6, really, you didn't like it too much?? I use it all the time in my scopes and like the lightness and compactness of it. Works really well in my 80ED for medium power, but never looked through the Delos or Pentax though.

Bob




If you get a chance, you should look through one. You might just find that T6 to be lacking in ways you didn't know.


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: mgwhittle]
      #6034690 - 08/19/13 02:36 PM

So far, no ES or Televue Nagler I've looked thru matches the XW (at the 10mm and below). I have not looked thru a Delos, but understand they're a flip-a-coin comparison with the XWs. I really do like the XW's adjustable eye relief cap though, it's very smooth and allows fine adjusting (not just gross adjustments like the NLV cap).

Post Extras: Print Post   Remind Me!   Notify Moderator  
dscarpa
Post Laureate
*****

Reged: 03/15/08

Loc: San Diego Ca.
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6034699 - 08/19/13 02:41 PM

I find my 17.3 & 12 Delos, 13 Ethos and 7 & 10 XWs combined with my barlows-Powermates to be a Dream Team! David

Post Extras: Print Post   Remind Me!   Notify Moderator  
Ralph Steudtner
member
*****

Reged: 07/13/12

Re: Pentax XW versus Delos, an informal comparison new [Re: mgwhittle]
      #6034796 - 08/19/13 03:35 PM

I have a 13T6 as well as Pentax and Delos eyepieces. I like the 13T6 because it is small and lightweight and provides tack sharp star images across the entire fov without a Paracorr. However, if you are talking transmission and color rendition, you can't beat the Pentax and Delos IMO.

Post Extras: Print Post   Remind Me!   Notify Moderator  
george golitzin
Carpal Tunnel
*****

Reged: 02/24/06

Re: Pentax XW versus Delos, an informal comparison new [Re: Ralph Steudtner]
      #6034891 - 08/19/13 04:27 PM

Nice report, François, thank you. Your observations are similar to mine, and the two lines do live together quite well. For what it's worth, I'm pretty certain the FC you saw in the 14 Delos was from your refractor--is it an ED doublet maybe? I also agree with you about your star colors in clusters observation. I liked the type 6 naglers a lot, but as I got older they got less comfortable; and I also just plain preferred the views in the XWs, so I sold all my T6 naglers after getting the XWs; the last to go was the 13T6, when the 14 delos finally came out.

I recently acquired the 8mm delos and have a 6mm Delos on the way--maybe I'm crazy, but I bought these to fit into my 5, 7, and 10 XW collection, selling the 3.5 pentax to help finance them. I might consider, down the road, selling the 5 and 7 XW and picking up the 4.5 D--I like the slightly tighter grouping of focal lengths in the delos line. But for now I'm going to hold on to those eyepieces and spend a lot of time seeing which ones I actually use. Lately, I had been getting away from my shorter scopes, using mostly the 12.5- and 18-inchers, so the 3.5XW hardly ever came out of the case--meanwhile I had been experimenting with barlows, kind of stupidly, to fill the "gaps" in my 1.4X sequence of pentaxes. So now I've filled those gaps with the 6 and 8 delos, and I'll pull out a barlow if I want anything shorter than 5mm.

Ergonomically, I still slightly prefer the XWs, but visually, I may be starting to lean delos-ward. I look forward to comparing the 6, 7, and 8 mm eyepieces on planets; also, to date the 7mm XW has been my main eyepiece for galaxy clusters in the 18-inch, and I look forward to testing that against the 6 and 8 deloi as well. They're both just superb eyepiece lines, and I'm very happy to own them.

-george


Post Extras: Print Post   Remind Me!   Notify Moderator  
Phillip Creed
Idiot Seeking Village
*****

Reged: 07/25/06

Loc: Canton, OH
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6034900 - 08/19/13 04:36 PM

Quote:

I am not an eyepiece expert as Bill Paolini or Philip Creed, so this thread is more of what i saw and my personnal impression.

Now i am done buying EPs. I thought i was done after purchasing the Pentax, but the Delos are just as good and offered more possibility in terms of FL, so i combined both lines of EPs in my EP case, and they live very well together.




Francois,

"Eyepiece Expert"?! Moi? Bill Paolini could write a book on eyepieces. Heck, Bill Paolini HAS written a book on eyepieces for that matter. I've looked through my share of eyepieces, and I know a good one when I see one, but I'm not quite expert level.

I will second the notion that the Delos and XW's are more or less interchangeable and will peacefully coexist in an eyepiece case. I'm looking to get a 7XW in the near future to complement my 14mm and 10mm Delos eyepieces. You really can't go wrong mixing up the series based on focal length, with the notable exception of the 14mm.

And, yes, I'm thinking the T6's will end up with the short end of the stick here. My 14mm Delos has roughly the same field stop as my old 13T6, but with a *LOT* more eye relief. As long as you're willing to lose a tiny bit of magnification vs. a T6 Nagler, going up to the next focal length in the Delos/XW series is well worth it, IMO.

Clear Skies,
Phil


Post Extras: Print Post   Remind Me!   Notify Moderator  
george golitzin
Carpal Tunnel
*****

Reged: 02/24/06

Re: Pentax XW versus Delos, an informal comparison new [Re: BillP]
      #6034911 - 08/19/13 04:43 PM

Quote:

... Getting past the optical and into the ergonomics/mechanicals, what was your impression of the mechanical eye guard differences between the XW and Delos? Did one fare better than the other after extended use, or more of 6/one, half dozen of the other?




Bill, if I might offer my impressions... I really like the ease of the adjustment system on the Delos versus the pentax--it's much quicker than screwing/unscrewing the eyecup, and it's just as solid. But in fact I rarely adjust this unless I have someone who wants to look though the eyepiece with glasses on, so this is not a big deal for me--except that I have to make extra room in my eyepiece case to accommodate the eyepieces, since I leave them near their full extensions.

However, I prefer the feeling of the XW eyecup on my brow--it's a little bit broader than that of the delos, the rubber casing is a bit thicker, and so it just feels better. Also sometimes I wish the eyecup on the delos would come out one or two more mm, but that's not a biggie. Overall, the experience of using one or the other is very similar. I think also that the view itself has a lot to do with the impression of comfort--I'm not sure how to put this, but there's nothing funny going on in the image formed by the eyepiece--it's just so easy to look at and examine for detail. I find that true of both lines.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: REC]
      #6034969 - 08/19/13 05:13 PM

Quote:

The 13t6, really, you didn't like it too much?? I use it all the time in my scopes and like the lightness and compactness of it. Works really well in my 80ED for medium power, but never looked through the Delos or Pentax though.

Bob




Indeed, I bought a pair of them for use in an Oberwerk BT-100-45 binocular telescope. Within those confines (and at that time) they were seemed like a great choice. But the 24 Pans seemed at least as nice to me - more pop.

I did use them (well, one of them) in my telescopes on occasion. I am sure you are familiar with the reaction that certain eyepieces can cause - that WOW! feeling - such as the T4 Naglers. The 13 T6 just didn't have it. The views were ... uninspiring ... for lack of a better word. I had the 13 Ethos at the time and preferred it. Unfortunately, I missed a golden opportunity to put them head-to-head. It just didn't occur to me.

Getting back to topic, the 14 Delos supplanted the 13 Ethos for that slot in my eyepiece case.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6034975 - 08/19/13 05:15 PM

Quote:

thanks for the kind words. i view with glasses on so they all have the mechanical eyegard down. i think i would find both systems pleasant to work with. at first i did not understand how the delos worked but understood it after a couple of minutes ( i am not the engineer-type) while the pentax system was easy immediately. frankly i think the delos system is cleaver.




The Delos eye guard is certainly a vast improvement over Instajudst.

However, I wish the folks at TeleVue would have just eaten a slice of humble pie and copied the Pentax system.


Post Extras: Print Post   Remind Me!   Notify Moderator  
JayinUT
I'm not Sleepy
*****

Reged: 09/19/08

Loc: Utah
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6035055 - 08/19/13 05:58 PM

Quote:

However, I wish the folks at TeleVue would have just eaten a slice of humble pie and copied the Pentax system.




I agree with that statement.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman81
Carpal Tunnel
*****

Reged: 03/06/08

Loc: Metro Detroit, MI, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6035083 - 08/19/13 06:07 PM

Quote:


However, I wish the folks at TeleVue would have just eaten a slice of humble pie and copied the Pentax system.




BIG +1 here!

Francois, nice write-up, thanks!


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Phillip Creed]
      #6035175 - 08/19/13 06:46 PM

Quote:

Quote:

I am not an eyepiece expert as Bill Paolini or Philip Creed, so this thread is more of what i saw and my personnal impression.

Now i am done buying EPs. I thought i was done after purchasing the Pentax, but the Delos are just as good and offered more possibility in terms of FL, so i combined both lines of EPs in my EP case, and they live very well together.




Francois,

"Eyepiece Expert"?! Moi? Bill Paolini could write a book on eyepieces. Heck, Bill Paolini HAS written a book on eyepieces for that matter. I've looked through my share of eyepieces, and I know a good one when I see one, but I'm not quite expert level.

Clear Skies,
Phil




Well, you are not far from one after reading your posts. I enjoy reading Bill reviews and posts but i realize that many of the small differences he sees are outside of my abilities.

In a way, the evaluation of someone who understands well aberrations and uses scopes similar to mine is very important, and is a good guide for my choice.


Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6035285 - 08/19/13 08:02 PM

Nice report! I also own both Delos and Pentax XWs, and have found them to be equal--equally excellent eyepieces. If I were trying to choose, I would be guided by the differences in focal lengths. They both have a 10, then the XW moves to a 7 and 5 while the Delos goes from an 8 to a 6. They do overlap in some focal lengths.

Post Extras: Print Post   Remind Me!   Notify Moderator  
HaleBopper
scholastic sledgehammer


Reged: 01/14/08

Loc: Land of Ice and Snow
Re: Pentax XW versus Delos, an informal comparison new [Re: GeneT]
      #6035381 - 08/19/13 09:02 PM

A very good read! I was thinking of a 12 mm Delos the other day, and now you got be back on it.

I don't get a chance to do visual that much anymore, but I was wanting to get an eyepiece in the 12 mm range for planet viewing through my C11 Edge. I already have 10 mm Pentax XW and was considering either a 12 mm TV Plossl or a 12 mm Delos.

From the Delos users here, how well does the Delos perform on planets? You can tell from my signature I have a few eyepieces, but was wanting to upgrade a little.

Thanks.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: HaleBopper]
      #6035391 - 08/19/13 09:08 PM

Quote:

From the Delos users here, how well does the Delos perform on planets?




It would not be my Top Choice, but it would be my Top Wide Field Choice. It's quite nice really.

This fall we'll see how well my new Pentax XW stacks up.


Post Extras: Print Post   Remind Me!   Notify Moderator  
eklf
Pooh-Bah
*****

Reged: 05/12/07

Loc: Carrboro, NC
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6035421 - 08/19/13 09:37 PM

In light of Televue's perfectly-deserved stellar reputation for continously pushing the envelop on eyepiece designs,I am somewhat surprised (and a tad disappointed) that the Delos series simply equaled what Pentax achieved over a decade ago. This is quite a feat on the part of Pentax.

Post Extras: Print Post   Remind Me!   Notify Moderator  
ibase
Vendor Affiliate
*****

Reged: 03/20/08

Loc: Manila, Philippines 121*E 14*N
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6035440 - 08/19/13 09:49 PM

As much as I love the Delos, the Nagler T6 will never leave the stall - the wider field of view of 82-deg. just trounces the Delos/Pentax in this regard where the latter cannot approximate the "space-walk" feel and sensation when one is using the Nagler T6, and its optical prowess is nothing to sneeze at too, not to mention tack sharp stars across the entire field. Add to that the small, light and streamlined format (compared to the Delos/Pentax) then everything falls into place and seals the deal. I understand that the shorter eye relief of the NT6 does not make it ideal for eye-glass wearing observers (like the OP) where the entire space-walk field may not be visible or fully appreciated, but otherwise, it's a great EP to have in the stall - it can peacefully co-exist with the Delos, the NT6 is a fine instrument to engage in when one wants that falling-into-the-eyepiece sensation. Just 2 cents.


L-R: Nagler 5mm T6, Delos 6mm, ES-100 14mm

Best,


Post Extras: Print Post   Remind Me!   Notify Moderator  
Phillip Creed
Idiot Seeking Village
*****

Reged: 07/25/06

Loc: Canton, OH
Re: Pentax XW versus Delos, an informal comparison new [Re: HaleBopper]
      #6035443 - 08/19/13 09:51 PM

Quote:

From the Delos users here, how well does the Delos perform on planets?




They're really, REALLY good on planets. I've looked at Jupiter in many instruments at 200X (close to the typical seeing limits here in NE Ohio), but I have never, EVER seen it sharper than with a 10mm Delos + 2X GSO barlow combo in my 8" f/4.9 reflector. Yes, even with a barlow, it was incredibly crisp. And I've owned (and barlowed) T6 Naglers, Ethoses and ES-100's in the past; the Delos beat 'em all.

My 14mm Delos was enough to easily see the Cassini Division at the ansae of Saturn's rings in my 8" f/4.9. That's only 71X.

Clear Skies,
Phil


Post Extras: Print Post   Remind Me!   Notify Moderator  
tonyt
professor emeritus


Reged: 09/02/09

Loc: Australia
Re: Pentax XW versus Delos, an informal comparison new [Re: Phillip Creed]
      #6035488 - 08/19/13 10:19 PM

Just an FYI, the 17.3 Delos seated fully into the Astrosystems Ultra Low eyepiece adapter is close to parfocal with a 13mm Ethos. (ethos in 2" mode). Apart from dealing with limited focuser travel having parfocal eyepieces is handy for setting the Paracorr.

Edited by tonyt (08/19/13 10:22 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
ibase
Vendor Affiliate
*****

Reged: 03/20/08

Loc: Manila, Philippines 121*E 14*N
Re: Pentax XW versus Delos, an informal comparison new [Re: tonyt]
      #6035765 - 08/20/13 02:19 AM

The Delos eyecup is better, it takes less time & effort to make it fully extended compared to the Pentax XW, it has markers too that serve as a setting guide and it's uniquely innovative.

Best,


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: ibase]
      #6035939 - 08/20/13 07:37 AM

Quote:

The Delos eyecup is better, it takes less time & effort to make it fully extended compared to the Pentax XW, it has markers too that serve as a setting guide and it's uniquely innovative.

Best,




I agree i find the delos system quite cleaver and easy to use.

As for planets, i saw no difference between details provided by a brandon unbarlowed and the 12 delos or the 6 when using a barlow with the brandon. The view through the brandon was special without giving more details. I found bands on saturn were better seen with the delos than a equivalent BGO ortho.

As for the t6 nagler, i never had the spacewalk feeling with those and they fogged easily in winter, and using them with glasses turned them into plossls. They are sharp and wide field plus are not heavy, but they are far from perfect. The delos are near perfection


Post Extras: Print Post   Remind Me!   Notify Moderator  
HaleBopper
scholastic sledgehammer


Reged: 01/14/08

Loc: Land of Ice and Snow
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6035953 - 08/20/13 07:53 AM

Thanks everyone for the planet performance input. For less cost I think I'll pick up a few TV Plossls for the planets, but will plan on gradually adding a few Delos to replace my current Stratus eyepieces.

Thanks again for the input.


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: HaleBopper]
      #6035992 - 08/20/13 08:30 AM

Quote:

Thanks everyone for the planet performance input. For less cost I think I'll pick up a few TV Plossls for the planets, but will plan on gradually adding a few Delos to replace my current Stratus eyepieces.

Thanks again for the input.




the 15 plossl would be great in your C11. TV plossls give great views of jupiter and saturn. the coffe tone pf these EPs is an advantage for viewing jupiter in my experience


Post Extras: Print Post   Remind Me!   Notify Moderator  
HaleBopper
scholastic sledgehammer


Reged: 01/14/08

Loc: Land of Ice and Snow
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6036022 - 08/20/13 08:58 AM

Yes thanks. I had my eye on the 15 but will probably get the 11 as well. Still on the fence on whether or not to get the 8. Usually more magnification than I can handle with my average skies.

Will definitely be looking to pick up a Delos or two in the future.


Post Extras: Print Post   Remind Me!   Notify Moderator  
kkokkolis
Carpal Tunnel
*****

Reged: 09/23/09

Loc: Piraeus, Greece
Re: Pentax XW versus Delos, an informal comparison new [Re: mgwhittle]
      #6036212 - 08/20/13 10:43 AM

Quote:

This was also a shock to me when I started using my Delos. If you think the colors aren't visible in the T6, try the Explore Scientific eyepieces. They are absolutely monotone compared to the Delos.




To what line are you referring to? I don't see much difference between ES100 9 and Delos 10, but I haven't compared ES82 6.7 and Delos 6. I'll remember to check next time. And the only ES68 I have (24) is good, just short of the Hyperion Aspheric 31. I'll check again, on Albireo first and then some fainter stars.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Pentax XW versus Delos, an informal comparison new [Re: HaleBopper]
      #6036231 - 08/20/13 10:51 AM

Those who, like me, crave actual lab tests on eyepieces might be interested to read this report (use Google Translate unless you read in French):
http://www.cieletespace.fr/files/InstrumentTest/201306__6_oculaires_10mm.pdf
which tests several 10mm widefield eyepieces, including a Delos and an XW.
Spoiler alert: 10mm Delos rated #1.

I wish we could get tests like this from US magazines. Sigh.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6036300 - 08/20/13 11:38 AM

If I'm reading the results of the French report correctly, the Delos 10 and Pentax 10 both received scores of 6/6 for light transmission. For deep sky - for me at least - light transmission has high priority. These results contradict Alvin Huey's field reports, which indicate the Delos have better light transmission than the XW's. (Two caveats are that the differences would not be as obvious for smaller instruments or for the longer focal length eyepieces used at lower magnifications.)

When I use eyepieces for planet/lunar, I'm not concerned so much about light transmission. But for deep sky, I'm often looking for DSO that I've never seen before, so they tend to be toward the LM of my 10" Dob. In that case, I'd consider Alvin's results.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6036310 - 08/20/13 11:46 AM

This is the Babylon 10 translation of the French report's test for light transmission:

Quote:

TRANSMISSION OF LIGHT by projecting the image of an artificial star on the cell with a photometer, we have been able to measure the variations of transmission between the different eyepieces. The results obtained are rather good, with very low differences found, at most 0.08 magnitude




Babylon 10 French to English

So should we accept that the Delos 10 and XW 10 have essentially equal light transmission, since they both received a 6/6 on the French report? How does this square with field reports which indicate the Delos have greater light transmission? Personally, I tend to put more weight on field reports from experienced observers rather than lab tests. For instance, would the photometer be sensitive to the same range and peaks of light frequencies that a dark-adapted eye would have in actual field conditions?

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6036381 - 08/20/13 12:20 PM

Mike,

The human eye doesn't have its peak sensitivity over the entire spectrum.
One of the areas for further research is the spectrum of transmission of eyepieces. Measuring peak transmission at 532nm (green laser) can give you one figure only. A white-light artificial star won't have a uniform spectrum, either, so what does measuring transmission with that light suggest? Does that white light have sufficient output from 400-500nm to be able to give a good spectrum of short wavelength response?

If you look at the Pentax XW transmission spectra here you'll see there is a precipitous roll-off below 450nm.

Does the fact we have our greatest eye sensitivity at 500nm at night, using scotopic vision, mean this will have an effect on what we see or detect?

I don't see much in the way of a red roll-off in the XWs, but people report seeing reds better in the Delos. What does that mean?

The Ethos did the best at f/3.5. Does that mean it is optimized for short f/ratios?

How significant is a measured transmission difference of 0.08 magnitude? And were measurements taken once, or multiple times and averaged? That small a difference says transmission differences won't be easily revealed in the field.

A test like this always brings up additional questions. It is interesting to see how high the Delos scores, though it barely beat the Ethos.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6036449 - 08/20/13 12:53 PM

Don,

Good questions about light transmission of eyepieces. These are the sort of uncertainties about the light transmission test in the French report which made me question the results. The little bit of jargon that was provided by the article did not impress me. "TRANSMISSION OF LIGHT by projecting the image of an artificial star on the cell with a photometer." Yes ... so what? We need more information than that to determine if the results can be extrapolated to scotopic human eyes. Amateur astronomers are not photometers.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tank
Carpal Tunnel
*****

Reged: 07/27/09

Loc: Stoney Creek, Ontario, CANADA
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6036546 - 08/20/13 01:39 PM

Taste
-Do you like immersive view?
-Do you like seeing Field stop?
-Do you like eye relief?
-Do you like more neutral tone?
-Do you like Heavy big EPs?

These are some questions to be asked too before someone picks these top of the line EPs!
For me nothing beats the XWs yet as a entire Package!
Looked thru the Delos 8,12,14,17.3, Nikon NAV 17.5, Ethos 13, All XWs except for 40mm.
For me the Delos comes close to the XW but the comfort is just not there. Now XWs do have a issues at say 14,20mm FL here I would select a Delos due to FC in newts.
Ethos is just way to immersive for me personally!
Optics are great on all these!


Post Extras: Print Post   Remind Me!   Notify Moderator  
t.r.
Post Laureate
*****

Reged: 02/14/08

Loc: Upstate NY
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6036587 - 08/20/13 02:00 PM Attachment (16 downloads)

Quote:

This is the Babylon 10 translation of the French report's test for light transmission:

Quote:

TRANSMISSION OF LIGHT by projecting the image of an artificial star on the cell with a photometer, we have been able to measure the variations of transmission between the different eyepieces. The results obtained are rather good, with very low differences found, at most 0.08 magnitude




Babylon 10 French to English

So should we accept that the Delos 10 and XW 10 have essentially equal light transmission, since they both received a 6/6 on the French report? How does this square with field reports which indicate the Delos have greater light transmission? Personally, I tend to put more weight on field reports from experienced observers rather than lab tests. For instance, would the photometer be sensitive to the same range and peaks of light frequencies that a dark-adapted eye would have in actual field conditions?

Mike




That is the real point. But, there hasn't been enough reports that agree to arrive at a consensus on this. Hence, we are left only with human bias.
Myself and a friend compared the views between the 10 Delos and 10 XW in a TEC 180 FL targeted on comet Garradd and M71. It presented an opportunity to show any contrast/limiting magnitude differences at this scale. There were none. My friend liked the eyecup positioning better on the Delos. I liked the positioning better on the XW. It came down to ergonomics.


Post Extras: Print Post   Remind Me!   Notify Moderator  
kkokkolis
Carpal Tunnel
*****

Reged: 09/23/09

Loc: Piraeus, Greece
Re: Pentax XW versus Delos, an informal comparison new [Re: t.r.]
      #6036604 - 08/20/13 02:12 PM

But we know that all these are good and differences of less than 10% are hardly perceivable by human beeings, unless instructed (through behavioral learning) to perceive them, placebo or not.
You say "splitting hairs" and he say "searching fleas in a haystack" here. Since we enjoy it there's nothing wrong,and it is our honest right to know which is the best before we spend our money, but one can enjoy stargazing with Delos, or Ethos, or Pentax XW, or Vixen, or even a Hyperion.
I know you all know it (in fact I learned it here) but I felt the need to express it. This might save me from a new eyepiece shopping spree.


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: kkokkolis]
      #6036632 - 08/20/13 02:25 PM

"This might save me from a new eyepiece shopping spree."

There's a cure for that...


Post Extras: Print Post   Remind Me!   Notify Moderator  
kkokkolis
Carpal Tunnel
*****

Reged: 09/23/09

Loc: Piraeus, Greece
Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6036658 - 08/20/13 02:36 PM

Quote:

"This might save me from a new eyepiece shopping spree."

There's a cure for that...




Spending all my money on an expensive apo?
I suggested that to my wife but she prefers diamond earings.


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: kkokkolis]
      #6036687 - 08/20/13 02:51 PM

Diamonds make fantastic lenses for eyepieces.......kinda expensive though....

Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Pentax XW versus Delos, an informal comparison new [Re: Tank]
      #6036753 - 08/20/13 03:26 PM

Quote:

Taste
-Do you like immersive view?
-Do you like seeing Field stop?
-Do you like eye relief?
-Do you like more neutral tone?
-Do you like Heavy big EPs?




Good questions. I answer:
-Yes, the wider the better. if the eye relief is sufficient, and you have developed the skill of holding the pupil fixed while the head rolls around to look at the edges (say, after several years of using 82 degree eyepieces), who wouldn't prefer a picture window to a pinhole? Especially if it comes with increased sharpness and better star color renditions.
-Don't care. I don't have field stops in my eyes. This is not precluded by having 100-120 degrees. Simply roll your head and look at it. Even in a 70 degree field, if you look left to see the field stop you aren't looking at the field stop on the right side--you can't see the entire field stop with direct vision simultaneously. The difference is that you can move your eye back and forth to see the edges without moving your pupil away from the exit pupil. In a 100+ degree eyepiece, if you tried that you'd occult the exit pupil. You have to hold the pupil steady and roll the head. It's a little different, but it's a skill easily developed.
-Don't care. I observe without glasses. If you have to wear glasses, the widest fields may not be for you. That's really OK when one has to "settle" for the likes of Delos and XW eyepieces. For less.
-I don't know what you're talking about. The objects I view don't show colors. Everything is gray. Is this really an issue for anyone except the Moon viewer? I've noticed that a good yellow filter brights out small details on the Moon incredibly. That's not "neutral". Is complete neutrality always good? And is any eyepiece tinted to the degree of even a light filter, or we talking about the difference in degrees of white? Do you still see any hint of coloration after 10 seconds? That would be unusual.
-My scope handles everything up to 4 lbs easily. It might balk at 6-7 lbs.
I believe that means all eyepieces work just fine, regardless of weight. Balance is always an issue in scopes. Many of the scopes in the '50s and '60s had external sliding weights on the tubes. They were there for a reason. I wish we could get back to that and just stop worrying about the weight of eyepieces. Or learn to construct scopes with relative immunity to the mis-balance caused by various eyepiece weights.

Of course, I can see circumstances where one could have different answers. Some of those aren't a matter of taste (e.g. heavy eyepieces) but more a matter of matching eyepieces to the other equipment chosen.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6036791 - 08/20/13 03:49 PM

I did a comparison between a 14mm Delos and a 14mm ES 100 on NGC-6946 in Cepheus. The 14mm Delos had better transmission as I could see, but the difference was only slight.

The 14mm ES 100 in question used in the comparison was the one that went flying in the air only to hit the ground below and it still worked perfectly.

I have the newer 14mm ES Argon 100 and in just looking through the bottom field lens, it appears to be clearer than my older one. I haven't had the chance to even try it yet and will be waiting for the moon to go away to do so.

In going back to 70 degree fields in eyepieces, it now feels restricted. I'd only grab an XW or two for planets, but I would keep my 14mm ES and 9mm ES 100's because the huge field just covers so much ground and I am basking in the giant FOV. I used to think 100 degree eyepieces were a gimmick, and once I tried them more and more, I am now addicted to them. The 14mm ES 100 is my favorite out of every eyepiece I own.

I've only had the 30mm ES 82 out once and need way more time with that one.....I was impressed with first light in it though. The last view I had with the 30mm ES 82 was just before I packed up at the darker site I go to: The Double Cluster was riding high in the N-E, and I have the view etched in my mind ~ It was really nice !!!!

Getting back on topic here ~ I've used the 6mm Delos and the 7mm XW. I preferred the ergonomics of the 7mm XW over the Delos. However, both are excellent eyepieces in their own right.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tank
Carpal Tunnel
*****

Reged: 07/27/09

Loc: Stoney Creek, Ontario, CANADA
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6036818 - 08/20/13 03:59 PM

Don
Proving my point my answers would be diffent then yours so I would prefer a different high quality of EP
-"Wider the better" is not for me I prefer to see the entire image in one shot therefore the Ethos takes a back seat.
-Seeing the FS easily is a preference of mine which I love having think about it do you like to have pictures without frames again people would answer yes and no to this so its a preference thing.
-I observe with and without glasses and well love the 20mm of ER.
-Neutral tone is more of a color saturation of stars and say color banding on Jupiter you might have a strong preference to a more warm tone therefore the TV products would be a better fit.
-WT im just saying because like you say based on they equipment if you have a GEM you maybe pushing it to the MAX already you want the light weight EP.

I've been observing with a few different individuals and I can say everyone put more stock into a specific attribute in a EP so a individual may see one EP better than another!
Bottom line use what works best for your taste!


Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Pentax XW versus Delos, an informal comparison new [Re: eklf]
      #6037003 - 08/20/13 05:53 PM

Quote:

In light of Televue's perfectly-deserved stellar reputation for continously pushing the envelop on eyepiece designs,I am somewhat surprised (and a tad disappointed) that the Delos series simply equaled what Pentax achieved over a decade ago. This is quite a feat on the part of Pentax.




I agree. I had owned and used several Delos eyepieces before I picked up a 7 and 5 XW. I was surprised that the XW's basically equalled the Delos.


Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Pentax XW versus Delos, an informal comparison new [Re: HaleBopper]
      #6037027 - 08/20/13 06:03 PM

You would have to go with an 11 TV Plossl. How important is eye relief to you? 6mm is not enough for me. https://www.astronomics.com/televue-11mm-polssl-eyepiece_p3303.aspx
I found the large eye lens and long eye relief of the Delos and XW's make doing high power work pleasurable. My eyes don't get tired due to eye strain.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rick M.
super member


Reged: 03/16/13

Re: Pentax XW versus Delos, an informal comparison new [Re: GeneT]
      #6037047 - 08/20/13 06:09 PM

Gene, can we assume that Pentax has not made any changes/upgrades to its EP coatings in the last decade?

Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6037053 - 08/20/13 06:12 PM

Quote:

This is the Babylon 10 translation of the French report's test for light transmission:

Quote:

TRANSMISSION OF LIGHT by projecting the image of an artificial star on the cell with a photometer, we have been able to measure the variations of transmission between the different eyepieces. The results obtained are rather good, with very low differences found, at most 0.08 magnitude




Babylon 10 French to English

So should we accept that the Delos 10 and XW 10 have essentially equal light transmission, since they both received a 6/6 on the French report? How does this square with field reports which indicate the Delos have greater light transmission? Personally, I tend to put more weight on field reports from experienced observers rather than lab tests. For instance, would the photometer be sensitive to the same range and peaks of light frequencies that a dark-adapted eye would have in actual field conditions? Mike




I always go with my own viewing tests and trust what I see. I also respect the results of carefully conducted lab tests. I am buying a few small glass, high throughput eyepieces to see if I can tell any differences. I am looking forward to BillP's book and his thoughts on this matter.


Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6037067 - 08/20/13 06:18 PM

I can't get Google translate to work on this. http://www.cieletespace.fr/files/InstrumentTest/201306__6_oculaires_10mm.pdfDoes
Does anyone have a direct link for this article in English?


Post Extras: Print Post   Remind Me!   Notify Moderator  
dscarpa
Post Laureate
*****

Reged: 03/15/08

Loc: San Diego Ca.
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6037082 - 08/20/13 06:28 PM

For nighttime use your impression of the T6s vs the Delos and XWs mirror my own. My three T6s are as good which is to say very good for HA however and see a lot of use in my Lunt 60. I've recently bought more than a few simple glass eyepieces with a 5 XO being the most recent and am comparing them to the widefields for day and night. David

Edited by dscarpa (08/20/13 06:33 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6037089 - 08/20/13 06:33 PM

Quote:


-Yes, the wider the better. if the eye relief is sufficient, and you have developed the skill of holding the pupil fixed while the head rolls around to look at the edges (say, after several years of using 82 degree eyepieces), who wouldn't prefer a picture window to a pinhole? Especially if it comes with increased sharpness and better star color renditions.




Quote:

-I don't know what you're talking about. The objects I view don't show colors. Everything is gray.




OK, so color is rendered better, or not there at all?

But about this pinhole business. The smallest AFOV in a production eyepiece is about 40 degrees (30 degree on a special order Monocentric from Markus at APM). Even the relatively small Monocentric AFOV is comparable to the AFOV most us experience sitting in their customary seat watching our lovely big screen TVs. If you don't believe it grab a tape measure and do the math.

AFOV is of course purely a personal preference, 70 degrees appears to be a very popular place to be. Wide fields without unusual and un-ergonomic head or neck contortions in the dark.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: GeneT]
      #6037099 - 08/20/13 06:39 PM

Quote:

I always go with my own viewing tests and trust what I see. I also respect the results of carefully conducted lab tests. I am buying a few small glass, high throughput eyepieces to see if I can tell any differences.




Yes, that is always the ultimate test because you buy equipment with your money, not the Lab's money.

It is amazing how we all seem to react differently to different scope and eyepiece combinations.


Post Extras: Print Post   Remind Me!   Notify Moderator  
JustaBoy
Post Laureate
*****

Reged: 06/19/12

Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6037178 - 08/20/13 07:21 PM

*AFOV is of course purely a personal preference, 70 degrees appears to be a very popular place to be. Wide fields without unusual and un-ergonomic head or neck contortions in the dark.*

Very well said, Jeff - Thanks for this!


Don - I know that you are correct in what you say, you're just not correct for all of us:-)

Thank you,
-Chuck


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: JustaBoy]
      #6037210 - 08/20/13 07:46 PM

Quote:

AFOV is of course purely a personal preference, 70 degrees appears to be a very popular place to be. Wide fields without unusual and un-ergonomic head or neck contortions in the dark.




I agree that 70° is a nice place to be, however, I use 82-100° eyepieces. I don't have to use any unusual "un-ergonomic head or neck contortions" to see the entire FOV in any of my eyepieces.


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6037247 - 08/20/13 08:14 PM



-I don't know what you're talking about. The objects I view don't show colors. Everything is gray. Is this really an issue for anyone except the Moon viewer? I've noticed that a good yellow filter brights out small details on the Moon incredibly. That's not "neutral". Is complete neutrality always good? And is any eyepiece tinted to the degree of even a light filter, or we talking about the difference in degrees of white? Do you still see any hint of coloration after 10 seconds?






Don, but when you look at star clusters, older cluster contain stars with different colors. I found that these colors were more vivid with the XW and delos (as well as the 17 ethos) than with the T6s. Star clusters do have colors (and planetaries have a blue-green tint).


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Pentax XW versus Delos, an informal comparison new [Re: Scanning4Comets]
      #6037297 - 08/20/13 08:52 PM

Quote:

I don't have to use any unusual "un-ergonomic head or neck contortions" to see the entire FOV in any of my eyepieces.



Agreed. The usual ergonomic contortions are the ones i use, personally.







Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Pentax XW versus Delos, an informal comparison new [Re: Mike B]
      #6037304 - 08/20/13 09:13 PM

Quote:

Quote:


-Yes, the wider the better. if the eye relief is sufficient, and you have developed the skill of holding the pupil fixed while the head rolls around to look at the edges (say, after several years of using 82 degree eyepieces), who wouldn't prefer a picture window to a pinhole? Especially if it comes with increased sharpness and better star color renditions.




Quote:

-I don't know what you're talking about. The objects I view don't show colors. Everything is gray.




OK, so color is rendered better, or not there at all?

But about this pinhole business. The smallest AFOV in a production eyepiece is about 40 degrees (30 degree on a special order Monocentric from Markus at APM). Even the relatively small Monocentric AFOV is comparable to the AFOV most us experience sitting in their customary seat watching our lovely big screen TVs. If you don't believe it grab a tape measure and do the math.

AFOV is of course purely a personal preference, 70 degrees appears to be a very popular place to be. Wide fields without unusual and un-ergonomic head or neck contortions in the dark.




OK, I can see where it looks like I was being inconsistent.

It is true that colored stars do show up better in certain eyepieces, but it is not, by and large, relevant to the galaxy and nebula viewing I do a lot of. And the tiny amounts of tint often described as "coffee tint" are irrelevant to the observing I do, even colorful nebulae.

You're right about watching TV and viewing angle, but that is really constrained compared to looking out a picture window and an ultrawide eyepiece is closer to the latter. But even a 70 degree field is a bit like a stage where our 30 degree direct vision is more like the spolight that moves from side to side to "see" it all. The only difference is that the wider eyepieces have a larger stage.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6037333 - 08/20/13 09:30 PM

François,
My observations correspond to yours as well.
I don't think we're talking about tint here, but the ability to see color more easily (or at all). I was a little too flippant in my remark about color, as there definitely are some colors visible through eyepieces, including on planets. And that is, in my opinion, a huge step beyond the minute coloration differences that people here ascribe to various eyepieces.

One test I read said that as the illumination on a white panel lessens that the human eye starts seeing yellows in the white, and that the reason is that we lost our ability to see the ends of the spectrum as illumination reduced, making yellow more prominent. So I wonder if the coloration some viewers see is actually a spectral difference in the light passing through the eyepiece, or merely a reduced transmission? And if it's the spectrum of transmission, if it's attributable to one specific glass type.

Here is something that might answer the question:
http://www.amateurastronomie.com/Astronomie/tips/tips3.htm


Post Extras: Print Post   Remind Me!   Notify Moderator  
ibase
Vendor Affiliate
*****

Reged: 03/20/08

Loc: Manila, Philippines 121*E 14*N
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6037500 - 08/20/13 11:38 PM

Quote:


As for the t6 nagler, i never had the spacewalk feeling .. .. and using them with glasses turned them into plossls.




That explains it. The Nagler T6 was never really meant for eyeglass wearing observers where one of its most salient features, the spacewalk sensation it affords, will be lost on them and not fully appreciated because the eyeglasses get in the way of seeing the entire field. The Delos/Pentax with its more generous eye relief are better suited for eyeglass use.

Best,


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: ibase]
      #6037808 - 08/21/13 07:20 AM

Hernando,

I must specify that i always used the T6 without glasses and did not have the spacewalk effect. I,was impressed by how small and ligth they were and sharp but the spacewalk effect i had only wwith the T4 and T5. I always considered the T5 are the best naglers


Post Extras: Print Post   Remind Me!   Notify Moderator  
dscarpa
Post Laureate
*****

Reged: 03/15/08

Loc: San Diego Ca.
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6038318 - 08/21/13 01:02 PM

No spacewalk with the T6s for me. On the plus side they are less seeing sensitive than the XWs and Delos when it came to seeing low contrast detail on Jupiter. For lunar it's the big boys hand down. They give a white highlands when clear and gray when there are thin clouds vs gray and a very off putting yellow with the Ts under the same conditions. David

Edited by dscarpa (08/22/13 04:01 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
kkokkolis
Carpal Tunnel
*****

Reged: 09/23/09

Loc: Piraeus, Greece
Re: Pentax XW versus Delos, an informal comparison new [Re: dscarpa]
      #6038453 - 08/21/13 02:28 PM

Maybe we use the marketing invented (I think, please correct me if wrong) term spacewalk with a personal approach and mean different things. Personally I can't imagine how a 20mm eye lens resembles a spaceship's scattle or a spacesuit's visor. It's like comparing a sprat to a tuna fish. My spacewalk is possible with an XW, Delos, T4, LVW, Hyperion etc, because they have a window- like lens you don't need to apply as a contact lens. I understand that different people have different eyes and preferences. I, for example, could never stand contact lenses and never tried one, while my wife and kids used them a lot. My family might be able to experience a spacewalk feeling even with a 4mm Plossl (but that has to be tested).

Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman81
Carpal Tunnel
*****

Reged: 03/06/08

Loc: Metro Detroit, MI, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: kkokkolis]
      #6038568 - 08/21/13 03:27 PM

The Type 4 Naglers are the only Naglers I have tried and they are all in the 'Spacewalk' class, no doubt about it.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman81]
      #6038599 - 08/21/13 03:42 PM

Agreed! The Ethoi are nice- VERY nice, with fantastic optics, and FoV horsepower like gangbusters... but they don't have the spacewalk *sense* the T4 Naglers do. And there's nothin' wrong with the T4 optics, either!

I like the throw-you-OUT-the-window explanation!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Pentax XW versus Delos, an informal comparison new [Re: kkokkolis]
      #6038619 - 08/21/13 03:50 PM

Quote:

Maybe we use the marketing invented (I think, please correct me if wrong) term spacewalk with a personal approach and mean different things. Personally I can't imagine how a 20mm eye lens resembles a spaceship's scattle or a spacesuit's visor. It's like comparing a sprat to a tuna fish. My spacewalk is possible with an XW, Delos, T4, LVW, Hyperion etc, because they have a window- like lens you don't need to apply as a contact lens. I understand that different people have different eyes and preferences. I, for example, could never stand contact lenses and never tried one, while my wife and kids used them a lot. My family might be able to experience a spacewalk feeling even with a 4mm Plossl (but that has to be tested).



Quite right. Even the 120 degree Explore Scientific eyepiece doesn't really resemble looking through a spacesuit helmet. It resembles, uh, looking through a really wide view eyepiece.
There is something kind of special about looking through a high power eyepiece with a really wide angle apparent field, though--when the field stop, though visible with peripheral vision, isn't noticeable with direct vision. You can really look around and see other stuff in the field up there and down there, and everything is at a relatively high magnification. When looking at a galaxy cluster, for instance, it gives more of a sensation of "space" between the objects. And it can aid identification (example: Stephan's Quintet, where 6 galaxies are readily visible when the close pair is magnified enough to see them as separates).

By the way, to see the full field of view of a 4mm Plossl requires, you know, a corneal implant. You remove the contact lens and attach the eye lens to the cornea. It's the only way to conquer that 2.8mm eye relief.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6038658 - 08/21/13 04:10 PM

Yeah, a 4mm Plossl soooooo ain't hap'nin'!


Ultra & hyperwides permit levels of magnification that enable SEEING many objects, all-at-once, where a standard 50* view would require panning the entire scope around to see- at least at the same magnification. I'd much prefer simply panning my eyeball around in order to look directly at, in turn, any number of objects in such a field... while still preserving the entire picture for an indirect, simultaneous view.

They also enable higher-mag views in a non-tracking scope, where a 50* view would be a constant pain to keep the object within... or worse, find it again when it sails off the edge between peeks. This cannot be stressed enough where sketching is concerned, or when sharing the views with other folks. Try puttin' a newb at the wheel of a Dob at 500x with a 50* Plossl!... an exercise in frustration- for you BOTH! Needless, too.


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6038728 - 08/21/13 04:50 PM

Quote:

Quote:



By the way, to see the full field of view of a 4mm Plossl requires, you know, a corneal implant. You remove the contact lens and attach the eye lens to the cornea. It's the only way to conquer that 2.8mm eye relief.




ouch, i will keep my delos!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman81
Carpal Tunnel
*****

Reged: 03/06/08

Loc: Metro Detroit, MI, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Mike B]
      #6038804 - 08/21/13 05:38 PM

Quote:

Agreed! The Ethoi are nice- VERY nice, with fantastic optics, and FoV horsepower like gangbusters... but they don't have the spacewalk *sense* the T4 Naglers do. And there's nothin' wrong with the T4 optics, either!

I like the throw-you-OUT-the-window explanation!




Whoa! That's not quite what I meant! The Nagler T4's are quite nice indeed but the Ethos is definitely spacewalk as well, how could it not be, unless we are defining the term differently.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman81]
      #6039133 - 08/21/13 08:47 PM

Well, as has been stated- and correctly so- there is some margin for personal impressions on this "spacewalk" thing.

The T4's, for me, do a much better job of simply vanishing... leaving me in space. I suspect it's due to their large eyelens, plus their gracious eye-relief; and i DO wear eyeglasses.

The Ethoi, for all their field, do not "vanish"... i'm always cognizant of looking THRU an eyepiece. But that's me. YMMV. And quite possibly so if you're a bare-eyed observer.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: t.r.]
      #6039418 - 08/22/13 12:41 AM

Quote:

Quote:

So should we accept that the Delos 10 and XW 10 have essentially equal light transmission, since they both received a 6/6 on the French report? How does this square with field reports which indicate the Delos have greater light transmission? Personally, I tend to put more weight on field reports from experienced observers rather than lab tests. For instance, would the photometer be sensitive to the same range and peaks of light frequencies that a dark-adapted eye would have in actual field conditions?

Mike




That is the real point. But, there hasn't been enough reports that agree to arrive at a consensus on this. Hence, we are left only with human bias.
Myself and a friend compared the views between the 10 Delos and 10 XW in a TEC 180 FL targeted on comet Garradd and M71. It presented an opportunity to show any contrast/limiting magnitude differences at this scale. There were none. My friend liked the eyecup positioning better on the Delos. I liked the positioning better on the XW. It came down to ergonomics.




I don't think that a consensus would necessarily rule out human bias, but might merely represent that bias which is held by the majority. However, such quibbling concerns have too much of the odor of postmodernist deconstruction for my taste. If an observer gives an honest report of superior light transmission in one eyepiece over another, based on comparisons of threshold objects (defined as very faint objects barely seen in a given telescope by a given observer under given conditions), I will give them the benefit of the doubt, dependent on further observations.

I'm sure M71 is not a threshold object in a 6" telescope. I'm not so sure about comet Garradd at the time it was near M71, but it doesn't seem so very dim at least in the photo. I'm also not sure if a 6" telescope would be a large enough aperture to show light transmission differences between a Delos and an XW. Now, maybe personal preferences on the eyecup differences between two eyepieces do show the observer's bias, but a good comparo of light transmission between eyepieces ought to be more straightforward and obvious. Maybe I'm too optimistic.


Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: Mike B]
      #6039457 - 08/22/13 01:16 AM

Quote:

They also enable higher-mag views in a non-tracking scope,





Well there's the problem.

Non-tracking is like going back to stone knives and bear skins.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6039477 - 08/22/13 01:40 AM

... or maybe THERE's the solution!


Quote:

...like going back to stone knives and bear skins.




Hey, it'll git 'er done.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: Mike B]
      #6039485 - 08/22/13 01:48 AM

Quote:

Well, as has been stated- and correctly so- there is some margin for personal impressions on this "spacewalk" thing.

The T4's, for me, do a much better job of simply vanishing... leaving me in space. I suspect it's due to their large eyelens, plus their gracious eye-relief; and i DO wear eyeglasses.

The Ethoi, for all their field, do not "vanish"... i'm always cognizant of looking THRU an eyepiece. But that's me. YMMV. And quite possibly so if you're a bare-eyed observer.





Yes, the 17T4 was a very visceral eyepiece as very few others are. At one time I said if I could only have one eyepiece, just weld the 17T4 into my focuser.

Then I tried the 13 Ethos. Optically, it was better and after careful comparison between myself and a neutral observer there was just no doubt about it. So I reluctantly sold off the 17T4 (and the 12T4).

But the 13 Ethos just wasn't an enjoyable eyepiece to use once the AFOV novelty wore off. What you said rings absolutely true. To see the field requires lots of (for lack of a better term) work. The longer the observing session is, the more you notice it.

But what to do at that point? I knew that I could not go back to the 17T4 since I had found a sharper eyepiece, any thought of doing so was merely nostalgia working against experience and better judgment.

Then Delos came along. After trying the 10 mm I knew this was the line I was waiting for. As many others have reported, I found it even better optically than Ethos. So it was merely a waiting game for the Tele Vue to release all of the focal lengths.

No, Delos is still not the visceral experience of the T4. But in the end the sharpness and contrast wins the day and I didn't have to bob my head like a pigeon to see everything. The slightly smaller size is easier on both of my scopes and greater eye relief was nice. And best yet, it did it about half the price. What's not to like?

And I still might go back for that 17T4


Post Extras: Print Post   Remind Me!   Notify Moderator  
Traveler
Pooh-Bah


Reged: 08/19/07

Loc: The Netherlands
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6039576 - 08/22/13 04:27 AM

"Then i tried the 14mm. Many complain about the FC with the 14 and 20 Pentax XW. Personally, i do not have any issue with these eyepieces with my refractor as there is no FC visible with these EP with that refractor."

Your experience is the same as mine: i don't see any fc in my AP refractor. In fact, the 14XW is my most used ep when observing.

Besides: what an excellent review you wrote here!


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Traveler]
      #6039682 - 08/22/13 07:50 AM

Quote:

"Then i tried the 14mm. Many complain about the FC with the 14 and 20 Pentax XW. Personally, i do not have any issue with these eyepieces with my refractor as there is no FC visible with these EP with that refractor."

Your experience is the same as mine: i don't see any fc in my AP refractor. In fact, the 14XW is my most used ep when observing.

Besides: what an excellent review you wrote here!




thanks, just wanted to share my initial impressions. surprisngly, the sky was clear ehen i got my deloi. now they started rolling in, delox or pentax , they all sit in my case


Post Extras: Print Post   Remind Me!   Notify Moderator  
t.r.
Post Laureate
*****

Reged: 02/14/08

Loc: Upstate NY
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6039743 - 08/22/13 08:59 AM

Quote:

Quote:

Quote:

So should we accept that the Delos 10 and XW 10 have essentially equal light transmission, since they both received a 6/6 on the French report? How does this square with field reports which indicate the Delos have greater light transmission? Personally, I tend to put more weight on field reports from experienced observers rather than lab tests. For instance, would the photometer be sensitive to the same range and peaks of light frequencies that a dark-adapted eye would have in actual field conditions?

Mike




That is the real point. But, there hasn't been enough reports that agree to arrive at a consensus on this. Hence, we are left only with human bias.
Myself and a friend compared the views between the 10 Delos and 10 XW in a TEC 180 FL targeted on comet Garradd and M71. It presented an opportunity to show any contrast/limiting magnitude differences at this scale. There were none. My friend liked the eyecup positioning better on the Delos. I liked the positioning better on the XW. It came down to ergonomics.




I don't think that a consensus would necessarily rule out human bias, but might merely represent that bias which is held by the majority. However, such quibbling concerns have too much of the odor of postmodernist deconstruction for my taste. If an observer gives an honest report of superior light transmission in one eyepiece over another, based on comparisons of threshold objects (defined as very faint objects barely seen in a given telescope by a given observer under given conditions), I will give them the benefit of the doubt, dependent on further observations.

I'm sure M71 is not a threshold object in a 6" telescope. I'm not so sure about comet Garradd at the time it was near M71, but it doesn't seem so very dim at least in the photo. I'm also not sure if a 6" telescope would be a large enough aperture to show light transmission differences between a Delos and an XW. Now, maybe personal preferences on the eyecup differences between two eyepieces do show the observer's bias, but a good comparo of light transmission between eyepieces ought to be more straightforward and obvious. Maybe I'm too optimistic.


Mike




Exactly my point Mike and why I posted the specific size used for the evaluation. Technically it is a 7" high quality apo, which many would equate with perfection and the limit of practical refractor aperture. It takes LARGER aperture to see the differences of limiting magnitude in these eyepieces as Alvin Huey and others demostrate. The target, IMHO provided an excellent combination of contrast variation with stars at the limit of visibility in the cluster and streamer contrast variations of the comet. There was no difference in these eyepieces with this level of quality gear and aperture. Why are the rest of us even worried about it if we have smaller aperture and perhaps lesser quality? There is no consensus with smaller aperture that differences exist. Use what is comfortable to YOU and don't fuss over the extreme ability that few of us ever get to enjoy was my point.


Post Extras: Print Post   Remind Me!   Notify Moderator  
ibase
Vendor Affiliate
*****

Reged: 03/20/08

Loc: Manila, Philippines 121*E 14*N
Re: Pentax XW versus Delos, an informal comparison new [Re: t.r.]
      #6039929 - 08/22/13 11:11 AM

All so true from a practical point of view, but may have missed one maybe inconsequential detail (or maybe not so), i.e. the natural propensity to want to own/buy the very best, never mind whether it can or cannot be discerned with one's own instruments or scopes (marketers of all sorts of products know this too well and can readily be seen in the preponderance of advertising copies touting "the best").

Best,


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6039988 - 08/22/13 11:45 AM

Quote:

Yes, the 17T4 was a very visceral eyepiece as very few others are. At one time I said if I could only have one eyepiece, just weld the 17T4 into my focuser.

Then I tried the 13 Ethos....

And I still might go back for that 17T4



Am myself in the same boat. Managed to pull together the full T4 set, "used"... then tried the 13 Ethos. The 17T4, having almost the same TFoV, went bye-bye very soon thereafter; the magnification factor of the 13E was notably better for my own, personal use.

However, i kept both the 12 & the 22T4's- the 12T4 for secondary scopes, and the 22T4 for the "visceral" plus wide-field combination.

I doubt i'll go back to the 17T4, but must admit that, while the 13E is better for my use in a clinical sense, the seat-of-the-pants aspect is just not there like with the T4.

Of course, it helps that i can always slap a pair of 22LVWs in the Denk where, OC'd in the Dob, they produce the identical magnification of the 17T4+Paracorr... and feeding both eyes simultaneously produces a viewing experience that buries even the T4 for immersion!

So it's just possible my optical "bucket-list" might include one day pairing up longer FL Deloi for the BVer...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Mike B]
      #6040087 - 08/22/13 12:56 PM

Quote:

Well there's the problem.

Non-tracking is like going back to stone knives and bear skins.




Tracking is nice, as I always tell my friends who have it....but w/o tracking one can really get personal with the sky and learn everything you possibly can about it. My tracking buddies are always asking me which star is which and where they are in the sky. IMO, it's good to know the sky, and what you are aiming at w/o the tracking....but at the same time, I'd love to just love to punch in a few buttons on the keypad and take a look!

Sorry for going off topic !!!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: t.r.]
      #6040091 - 08/22/13 12:58 PM

Quote:

Quote:

I don't think that a consensus would necessarily rule out human bias, but might merely represent that bias which is held by the majority. However, such quibbling concerns have too much of the odor of postmodernist deconstruction for my taste. If an observer gives an honest report of superior light transmission in one eyepiece over another, based on comparisons of threshold objects (defined as very faint objects barely seen in a given telescope by a given observer under given conditions), I will give them the benefit of the doubt, dependent on further observations.

I'm sure M71 is not a threshold object in a 6" telescope. I'm not so sure about comet Garradd at the time it was near M71, but it doesn't seem so very dim at least in the photo. I'm also not sure if a 6" telescope would be a large enough aperture to show light transmission differences between a Delos and an XW. Now, maybe personal preferences on the eyecup differences between two eyepieces do show the observer's bias, but a good comparo of light transmission between eyepieces ought to be more straightforward and obvious. Maybe I'm too optimistic.


Mike




Exactly my point Mike and why I posted the specific size used for the evaluation. Technically it is a 7" high quality apo, which many would equate with perfection and the limit of practical refractor aperture. It takes LARGER aperture to see the differences of limiting magnitude in these eyepieces as Alvin Huey and others demostrate. The target, IMHO provided an excellent combination of contrast variation with stars at the limit of visibility in the cluster and streamer contrast variations of the comet. There was no difference in these eyepieces with this level of quality gear and aperture. Why are the rest of us even worried about it if we have smaller aperture and perhaps lesser quality? There is no consensus with smaller aperture that differences exist. Use what is comfortable to YOU and don't fuss over the extreme ability that few of us ever get to enjoy was my point.




For myself, I'm not certain that the Delos would show superior light transmission versus XW's even in my 10" Dob. So far I've only bought a Delos 4.5 and 6 to fill in those slots among my XW's and lone LVW 8. I have seen transmission differences among XW, Sterling Plossl, Brandon and BGO when observing the Horsehead, a threshold object at my dark site for my 10" Dob. (The Sterling won!)

Judging from reports with instruments having apertures less than the 22" or so that Alvin Huey and friends are using, I might not see much if any difference in light transmission between Delos and XW. That's why I haven't replaced my XW 10 and 3.5 with the equivalent Delos. Now, maybe I should replace my LVW 8 with a Delos 8. But the LVW is just so nice and comfortable to my eye, I can't bear to do it.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: Scanning4Comets]
      #6040092 - 08/22/13 12:59 PM

In the time of stone knives and bear skins....they had dark skies...........

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6040108 - 08/22/13 01:05 PM

I'd rather have darker skies and no tracking.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6040152 - 08/22/13 01:29 PM

Quote:

I'd rather have darker skies and no tracking.

Mike




oh yes, big time


Post Extras: Print Post   Remind Me!   Notify Moderator  
t.r.
Post Laureate
*****

Reged: 02/14/08

Loc: Upstate NY
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6040197 - 08/22/13 01:52 PM

Quote:

The Sterling won!



I have heard good things about their transmission...I've never looked through or seen one.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: t.r.]
      #6040249 - 08/22/13 02:24 PM

They're good ... and cheap! I keep the Sterling Plossl 12.5, 17, 20 and 25 in my deep sky case. (I've removed the Brandons for use here at home. )

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6040592 - 08/22/13 06:18 PM

Quote:

They're good ... and cheap! I keep the Sterling Plossl 12.5, 17, 20 and 25 in my deep sky case. (I've removed the Brandons for use here at home. )

Mike




Exactly what i did with thecsterlings but have them in pairs for binoviewing


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6040675 - 08/22/13 07:19 PM

Quote:

They're good ... and cheap! I keep the Sterling Plossl 12.5, 17, 20 and 25 in my deep sky case. (I've removed the Brandons for use here at home. )

Mike




Speaking of Sterlings, I had a look at the Helix Nebula through a friend's 10" reflector with a 25mm Sterling Plossl and a Lumicon O-III filter and it's the brightest view of the Helix I have ever seen in my life.

I walked away from the scope wondering what kind of magic went on when I saw it. It really was that bright!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Scanning4Comets]
      #6040709 - 08/22/13 07:47 PM

I had a similar impression of the Horsehead with a Sterling 25 and H-Beta filter. An obviously brighter and more contrasty view.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
NHRob
Post Laureate
*****

Reged: 08/27/04

Loc: New Hampshire
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6040862 - 08/22/13 09:49 PM

I had a 40mmm Sterling plossl ... very nice and bright ep.

Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Pentax XW versus Delos, an informal comparison new [Re: kkokkolis]
      #6040870 - 08/22/13 09:54 PM

Quote:

Quote:

"This might save me from a new eyepiece shopping spree." There's a cure for that...




Spending all my money on an expensive apo?
I suggested that to my wife but she prefers diamond earings.




This is a 'both', not an either or situation.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6041110 - 08/23/13 01:14 AM

Quote:

In the time of stone knives and bear skins....they had dark skies...........




And a 30 year life expectancy.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6041124 - 08/23/13 01:37 AM

Quote:

I had a similar impression of the Horsehead with a Sterling 25 and H-Beta filter. An obviously brighter and more contrasty view.

Mike




I think getting one of these is in order! I remember reading about your experience with the Horsehead Nebula Mike, and at the time I just couldn't believe it because it was a cheaper eyepiece, then I tried it on the Helix and I was dumbfounded!

You were right all along and I retract whatever it was I said about your experience. I was WRONG.

Cheers!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6041128 - 08/23/13 01:39 AM

Quote:

Quote:

In the time of stone knives and bear skins....they had dark skies...........




And a 30 year life expectancy.



If they survived childhood, they lived generally longer than that.
Though there are fossil hominids that died younger, there are significant numbers of Neanderthal and early moderns that died in the 55-75 range.

Even after the cultivation of plants and the start of the Iron Age it was thought that "3 score and ten" (as written) was a reasonable expectation of life IF you didn't die of an accident, or warfare, or disease, etc. Though a lot of people died from disease when we started living in cities, this eased a lot after multiple generations because those prone to death from contagious diseases died. Though Smallpox was a horrible disease, at most 1/3 died from it and the rest survived.
For some reason, life expectancy plummeted with the fall of the Roman Empire, and it did, indeed, reach very low levels and didn't really climb back to "normal" until the industrial revolution. Was it hygiene? The foods eaten?
Warfare? The Plagues? Probably all of the above.

Sorry for the segue. Oh, to have seen the dark skies back then.

Edited by Starman1 (08/23/13 01:41 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
kkokkolis
Carpal Tunnel
*****

Reged: 09/23/09

Loc: Piraeus, Greece
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6041152 - 08/23/13 02:16 AM

Quote:

For some reason, life expectancy plummeted with the fall of the Roman Empire, and it did, indeed, reach very low levels and didn't really climb back to "normal" until the industrial revolution. Was it hygiene? The foods eaten?
Warfare? The Plagues? Probably all of the above.




Add lead chronic intoxication for Romans (lead was used excessively in their aquaducts) and lots of criminality in the dark ages (sea piracy and land armed thieves) later in the Middle ages. And underdeveloped obstetrics. Also, civilian life. Too many people living in crowded conditions, drinking from the same public taps etc.
This is among the first things taught in the medical school here. Hygiene (and prevention in general) is much better and cheaper for the community and the individual.
Sorry for off topic, but a comment about prevention can't hurt.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: kkokkolis]
      #6041362 - 08/23/13 07:57 AM

Quote:

Quote:

For some reason, life expectancy plummeted with the fall of the Roman Empire, and it did, indeed, reach very low levels and didn't really climb back to "normal" until the industrial revolution. Was it hygiene? The foods eaten?
Warfare? The Plagues? Probably all of the above.




Add lead chronic intoxication for Romans (lead was used excessively in their aquaducts) and lots of criminality in the dark ages (sea piracy and land armed thieves) later in the Middle ages. And underdeveloped obstetrics. Also, civilian life. Too many people living in crowded conditions, drinking from the same public taps etc.
This is among the first things taught in the medical school here. Hygiene (and prevention in general) is much better and cheaper for the community and the individual.
Sorry for off topic, but a comment about prevention can't hurt.




Drastic and relatively sudden changes in climate certainly have had effects on life expectation. During just the last millenium, mankind has experienced the Medieval Warming Period and the Little Ice Age. There must have been many other periods of climate change during the last 30,000 years.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Scanning4Comets]
      #6041389 - 08/23/13 08:18 AM

Quote:

Quote:

I had a similar impression of the Horsehead with a Sterling 25 and H-Beta filter. An obviously brighter and more contrasty view.

Mike




I think getting one of these is in order! I remember reading about your experience with the Horsehead Nebula Mike, and at the time I just couldn't believe it because it was a cheaper eyepiece, then I tried it on the Helix and I was dumbfounded!

You were right all along and I retract whatever it was I said about your experience. I was WRONG.

Cheers!




You never really know how good or bad an eyepiece is until you look through one yourself. You should know that better than anyone!


Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
t.r.
Post Laureate
*****

Reged: 02/14/08

Loc: Upstate NY
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6041467 - 08/23/13 09:13 AM Attachment (39 downloads)

Quote:

Sorry for the segue. Oh, to have seen the dark skies back then




I have had the opportunity to experience this...I deployed for Operation Restore Hope in '93 to the middle of Somalia, Africa where there was NO electricity or lights anywhere. Not even light domes on the horion. Look at the horn of Africa. I vividly recall looking out of my tent the first night we touched down at Baledogle airport at midnight, looked straight up and gazed upon the milky way...It was obvious that I was in the arm of a spiral galaxy that was all around me!!! I have never encountered as dark a sky since. My trusty C80SS got a workout that deployment. You can still experience it Don...Travel to it!


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: t.r.]
      #6041486 - 08/23/13 09:24 AM

Never been to Somalia (not sure I'd want too right now either), but the darkest skies I've seen were when I was stationed at Thule, Greenland.....no light domes, and for a few months, no light...period. Of course in summer, no darkness either!

Post Extras: Print Post   Remind Me!   Notify Moderator  
JustaBoy
Post Laureate
*****

Reged: 06/19/12

Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6041545 - 08/23/13 10:03 AM

Hi Guys,

If the Sterling 25mm is really something as special as some say, then that does not bode well for the rest of us:-(

They have been out of stock for quite some time (along with the 2" 40mm), and you know how it goes - If something is really good 'they' will quit making em:-)

Happens to me all the time...

Have a great day!
-Chuck


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: Pentax XW versus Delos, an informal comparison new [Re: t.r.]
      #6041641 - 08/23/13 10:52 AM

Quote:

Quote:

Sorry for the segue. Oh, to have seen the dark skies back then




I have had the opportunity to experience this...I deployed for Operation Restore Hope in '93 to the middle of Somalia, Africa where there was NO electricity or lights anywhere. Not even light domes on the horion. I vividly recall looking out of my tent the first night we touched down at Baledogle airport at midnight, looked straight up and gazed upon the milky way...It was obvious that I was in the arm of a spiral galaxy that was all around me!!! I have never encountered as dark a sky since. My trusty C80SS got a workout that deployment. You can still experience it Don...Travel to it!



Yup.
I'm going to Coonabarabran in Australia next March for a week under the stars. It's reputed to be quite dark.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman1]
      #6042761 - 08/24/13 12:35 AM

Quote:

Quote:

Quote:

In the time of stone knives and bear skins....they had dark skies...........




And a 30 year life expectancy.



If they survived childhood, they lived generally longer than that.
Though there are fossil hominids that died younger, there are significant numbers of Neanderthal and early moderns that died in the 55-75 range.

Even after the cultivation of plants and the start of the Iron Age it was thought that "3 score and ten" (as written) was a reasonable expectation of life IF you didn't die of an accident, or warfare, or disease, etc. Though a lot of people died from disease when we started living in cities, this eased a lot after multiple generations because those prone to death from contagious diseases died. Though Smallpox was a horrible disease, at most 1/3 died from it and the rest survived.
For some reason, life expectancy plummeted with the fall of the Roman Empire, and it did, indeed, reach very low levels and didn't really climb back to "normal" until the industrial revolution. Was it hygiene? The foods eaten?
Warfare? The Plagues? Probably all of the above.

Sorry for the segue. Oh, to have seen the dark skies back then.




To be honest I was don't know if the number was 25, 30, 45, or something else. Aside from the romanticized Hollywood view of aboriginals living in harmony with Nature, the reality of life was "nasty, brutish, and short" for the bulk of humanity before the availability of electricity and the modern hygiene it provides. Of course injury, warfare, and substenance living all pulled the average down quite a bit.

Not that we are free of those ills today, but at least Dobsonian owners have easy access to tracking solutions. Perhaps those that use them will be freed from the risk of Tracking Injuries, and live longer. Or we will become soft from our ease of life, less fit, and be more vulnerable to disease?

But enough of my segue. Yes the skies must have been great even until the time of say, Charles Messier.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6042831 - 08/24/13 01:36 AM

Quote:

...but at least Dobsonian owners have easy access to tracking solutions.



Yes, all i've gotta do is kill a bear with my stone-knife, and the tracking drive is mine!

I absolutely love the looks of the "SlipStream" drive on the SpicaEyes Dobs, but the pricing is a bit large & hairy. The ability to move the scope by hand, at will, and then let go to automatic tracking... schweet! Would certainly make EP comparos, like the Pentax vs. Delos, far easier to bear.

But given the budget i had to work with, i opted for (in descending order) aperture, premium optics, premium build, and DSCs... and then the dough ran out. Maybe someday, an upgrade?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Doc Willie
Carpal Tunnel
*****

Reged: 03/31/10

Loc: Mid-Hudson Valley, NY, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Mike B]
      #6043062 - 08/24/13 07:00 AM

Topic?

Post Extras: Print Post   Remind Me!   Notify Moderator  
MRNUTTY
Carpal Tunnel
*****

Reged: 11/22/11

Loc: Mendon, MA
Re: Pentax XW versus Delos, an informal comparison new [Re: Mike B]
      #6043106 - 08/24/13 07:44 AM

Quote:

I absolutely love the looks of the "SlipStream" drive on the SpicaEyes Dobs, but the pricing is a bit large & hairy.




"Eek!", to say the least! But lovely builds to be sure - envy...

On topic, I love my XW's and Delos, hard to let either go if needed someday.

Edited by MRNUTTY (08/24/13 05:16 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
A6Q6
professor emeritus


Reged: 05/31/11

Loc: Stroudsburg,Pa,U.S.A
Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6043546 - 08/24/13 12:43 PM

"Not that we are free of those ills today, but at least Dobsonian owners have easy access to tracking solutions. Perhaps those that use them will be freed from the risk of Tracking Injuries, and live longer. Or we will become soft from our ease of life, less fit, and be more vulnerable to disease?" Thanks I like that!!!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Scott in NCAdministrator
80mm Refractor Fanatic
*****

Reged: 03/05/05

Loc: NC
Re: Pentax XW versus Delos, an informal comparison new [Re: A6Q6]
      #6051288 - 08/28/13 06:54 PM

Okay, everyone--how about we get back to the topic of Pentax XW vs. Delos eyepieces?

Post Extras: Print Post   Remind Me!   Notify Moderator  
dvb
different Syndrome.
*****

Reged: 06/18/05

Loc: Vancouver, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Scott in NC]
      #6051391 - 08/28/13 07:50 PM

A link to my daylight comparison of 6mm Delos, 7mm Pentax, and 5mm Nagler. (I liked the Delos best.)

http://tinyurl.com/pw6ormw


Post Extras: Print Post   Remind Me!   Notify Moderator  
coutleef
Post Laureate
*****

Reged: 02/21/08

Loc: Saint-Donat, Quebec, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: dvb]
      #6052864 - 08/29/13 03:58 PM

thanks for the link

i have not tried them during the day yet.


Post Extras: Print Post   Remind Me!   Notify Moderator  
George9
sage


Reged: 12/11/04

Re: Pentax XW versus Delos, an informal comparison new [Re: Jeff Morgan]
      #6055250 - 08/30/13 10:39 PM

Quote:

Yes, the 17T4 was a very visceral eyepiece as very few others are. At one time I said if I could only have one eyepiece, just weld the 17T4 into my focuser.

Then I tried the 13 Ethos. Optically, it was better and after careful comparison between myself and a neutral observer there was just no doubt about it. So I reluctantly sold off the 17T4 (and the 12T4).

But the 13 Ethos just wasn't an enjoyable eyepiece to use once the AFOV novelty wore off. What you said rings absolutely true. To see the field requires lots of (for lack of a better term) work. The longer the observing session is, the more you notice it.

But what to do at that point? I knew that I could not go back to the 17T4 since I had found a sharper eyepiece, any thought of doing so was merely nostalgia working against experience and better judgment.

Then Delos came along. After trying the 10 mm I knew this was the line I was waiting for. As many others have reported, I found it even better optically than Ethos. So it was merely a waiting game for the Tele Vue to release all of the focal lengths.

No, Delos is still not the visceral experience of the T4. But in the end the sharpness and contrast wins the day and I didn't have to bob my head like a pigeon to see everything. The slightly smaller size is easier on both of my scopes and greater eye relief was nice. And best yet, it did it about half the price. What's not to like?

And I still might go back for that 17T4




Wow. What a great thread. Thanks for all the information. I've been away from the forum for a while.

I am living this now. My favorite eyepiece of all time, 17T4. My recent purchase, 13 Ethos, mainly to reduce eyepiece swapping in an 18" Dob. I am finding the exact same clinical improvement but not emotional impact.

My second favorite eyepiece of all time, 5.2 Pentax XL. (I love finding Mars's moons by using the field stop as an occulting bar with the moon just in and Mars just out.)

So you're telling me I will end up with a line of Delos or XWs. You guys are killing me.

But I'm not selling the 17T4.


Post Extras: Print Post   Remind Me!   Notify Moderator  
MRNUTTY
Carpal Tunnel
*****

Reged: 11/22/11

Loc: Mendon, MA
Re: Pentax XW versus Delos, an informal comparison new [Re: George9]
      #6056745 - 08/31/13 09:29 PM

Quote:

So you're telling me I will end up with a line of Delos or XWs. You guys are killing me.

But I'm not selling the 17T4.




it's OK! you can live with both the 17T4, XW's and Delos too!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman81
Carpal Tunnel
*****

Reged: 03/06/08

Loc: Metro Detroit, MI, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Scanning4Comets]
      #6169546 - 11/01/13 01:24 AM

Quote:

Quote:

Well there's the problem.

Non-tracking is like going back to stone knives and bear skins.




Tracking is nice, as I always tell my friends who have it....but w/o tracking one can really get personal with the sky and learn everything you possibly can about it. My tracking buddies are always asking me which star is which and where they are in the sky. IMO, it's good to know the sky, and what you are aiming at w/o the tracking....but at the same time, I'd love to just love to punch in a few buttons on the keypad and take a look!

Sorry for going off topic !!!




Markus, I think you assumed in your statement that tracking necessarily goes hand-in-hand with go-to. You can have a tracking platform (for a dob of course) that requires you to find objects and learn the sky by yourself.

BTW, this was a great thread and I hope to compare the Delos with my current XWs, starting with the 14mm focal length.. A good number of them are hitting the used market with regularity, so you can snag a deal with some diligence.

Edited by Starman81 (11/01/13 01:52 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scanning4Comets
Markus
*****

Reged: 12/26/04

Loc: Ontario, Canada
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman81]
      #6169554 - 11/01/13 01:32 AM

I said the above almost three months ago, LOL!

Yes, I did mean Go-to, however, I have a few friends who have tracking & Go-To and still ask where a lot of things are.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Starman81
Carpal Tunnel
*****

Reged: 03/06/08

Loc: Metro Detroit, MI, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: Scanning4Comets]
      #6169574 - 11/01/13 01:55 AM

Yes, it was a little while back but that doesn't mean I can let you off the hook!

There have been too many ortho threads in this forum recently so I needed to bring back a thread heavy on the wide-fields.


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman81]
      #6169778 - 11/01/13 08:24 AM

Ordered a 6mm Delos to fit between my Pentax 7 & 5mm...I believe they will play well together...No reason not to have both. For the hairs difference either way (depending on whose writing) they both perform brilliantly. I think its great they both come mostly in different f/ls, especially at the short f/ls, so we all benefit...

Post Extras: Print Post   Remind Me!   Notify Moderator  
kkokkolis
Carpal Tunnel
*****

Reged: 09/23/09

Loc: Piraeus, Greece
Re: Pentax XW versus Delos, an informal comparison new [Re: Starman81]
      #6169913 - 11/01/13 09:59 AM

Perhaps mr Delechie could combine some Ethos and T4 properties to provide a new eyepiece not even XWs could compare with. I'll propose a name. The closest island to Delos is called Myconos (but has not much to do with ethos I'm afraid).

Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: kkokkolis]
      #6169922 - 11/01/13 10:04 AM

I'd kinda like to see a Moe, Larry, and Curly Joe lines of eyepieces.

A 120*, 20mm eye relief, and the XW immersiveness would be hard to beat....or afford. But I'd love to look thru one.


Post Extras: Print Post   Remind Me!   Notify Moderator  
JustaBoy
Post Laureate
*****

Reged: 06/19/12

Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6169948 - 11/01/13 10:25 AM

How *BIG* do you think it would be? :-)

-Chuck


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: JustaBoy]
      #6169979 - 11/01/13 10:46 AM

Ok, and the size of a Meade RGO....

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6170003 - 11/01/13 10:58 AM

The eyepiece would have to be like a Tardis: bigger on the inside than on the outside. Maybe it would also allow you to travel in time and space. Wait a minute... My eyepieces already do that.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6170024 - 11/01/13 11:08 AM

The only problem I'm gonna have with mixing the Delos and XWs is I'm gonna need a bigger case.....

Down the road I may add the 8 Delos, that autta do it for the 68-72* fov (between Delos/XW/ES68/Pans, I'll have 3.5-34mm pretty well covered). I'm really finding I like the 68-72* fovs.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6170031 - 11/01/13 11:14 AM

Since getting a Leica ASPH, I'll probably sell my XW 5 and 7, and LVW 8. I think the XW 3.5, 10 and 20 will stay. Also, the Delos 4.5 and 6 aren't going anywhere in the near future.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Pentax XW versus Delos, an informal comparison new [Re: Sarkikos]
      #6170108 - 11/01/13 12:03 PM

Mike, I have a 6mm Delos on the way...how do you find it compares to the 5 & 7mm XW. I planned on using it to "fill" the 6mm slot as here 7mm is usually good for viewing, but 5mm can be a *BLEEP* shoot. Thought the 6mm Delos might get more use then the 5mm XW.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Scotophobe Maryland, USA
Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6170142 - 11/01/13 12:24 PM

So far, I like the "feel" of the XW 5 and 7 better. To my eyes, the exit pupil position is easier to find and maintain in the XW's. I know that some observers say the exact opposite. eh... I'm just giving my own experience.

I haven't done any direct comparison between my Delos 6 and the XW 5 and 7, since they are not the same focal lengths. I'm selling the XW 5 and 7 because I have compared them to my Leica ASPH, and found them close equivalents, though the Leica does exhibit that EOFB sometimes.

Mike


Post Extras: Print Post   Remind Me!   Notify Moderator  
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Pentax XW versus Delos, an informal comparison new [Re: coutleef]
      #6170214 - 11/01/13 12:58 PM

Quote:

here is no clear winner between these EP lines. I think the clear winner here is the amateur astronomer community : more choice and possibly some competition on price.




I agree! We are fortunate to have so many excellent choices of excellent eyepieces.


Post Extras: Print Post   Remind Me!   Notify Moderator  
MRNUTTY
Carpal Tunnel
*****

Reged: 11/22/11

Loc: Mendon, MA
Re: Pentax XW versus Delos, an informal comparison new [Re: csrlice12]
      #6170696 - 11/01/13 05:15 PM

Quote:

I'd kinda like to see a Moe, Larry, and Curly Joe lines of eyepieces.




which eyepiece is Shemp?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | (show all)


Extra information
27 registered and 32 anonymous users are browsing this forum.

Moderator:  ausastronomer, droid, Scott in NC 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 5090

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics