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14 Delos vs. 14 XW--has anyone compared?

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#1 Deep13

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Posted 11 October 2012 - 10:06 PM

I really like the 14 Pentax XW except in my f/5 12.5" scope at a dark site, the field curvature is pretty obvious. I wonder if anyone has had a chance to compare it to the 14 Delos.

#2 Scanning4Comets

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Posted 11 October 2012 - 10:10 PM

I'd LOVE to see that shootout too! :jump:

Delos would be corrected better I would guess.

#3 Doug Culbertson

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Posted 12 October 2012 - 05:20 AM

Is the 14mm Delos available yet?

As much as I have liked the XWs over the years, I would bet on the Delos at 14mm.

#4 coutleef

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Posted 12 October 2012 - 11:58 AM

I really like the 14 Pentax XW except in my f/5 12.5" scope at a dark site, the field curvature is pretty obvious. I wonder if anyone has had a chance to compare it to the 14 Delos.


have you tried it with a paracorr?

#5 Deep13

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Posted 12 October 2012 - 03:17 PM

It appears that it is not available yet. Guess I jumped the gun.

#6 Starman81

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Posted 12 October 2012 - 04:12 PM

Yeah that's the showdown I'm waiting on reading about as well. The Delos and XW only intersect in terms of focal lengths at 14mm, 10mm and 3.5mm... I think the Delos 10 and the XW 10 have been compared, can't remember at the moment how that one ended up. The other two Deloi have not been released yet.

#7 Deep13

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Posted 12 October 2012 - 08:51 PM

It seems the Delos has just a tad more transmission. That's what I got from the 10mm comparisons. The 14 under certain situations has noticeable field curvature, though not enough to be unusable and in the 8" f/6 not enough to really notice.

I don't have a Paracorr, responding to an earlier post. I don't have any ultrawide EPs and the 12.5" is pretty weight sensitive.

#8 Phillip Creed

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Posted 13 October 2012 - 10:01 AM

I really hope the 14mm Delos is what everyone else expects--just as sharp as an Ethos, just with 72-deg AFOV, more eye relief, and little/no field curvature

I know what I'm about to say this isn't going to please a lot of Pentax users, but here goes--I don't quite understand why the 14XW and the 20XW were released at all at full price given their field curvature. Yes, they've got great transmission and contrast, but field curvature to that magnitude is inexcusable for the price they command.

Sure, a Paracorr cleans it up. But a coma corrector shouldn't have to clean up anything *but* coma if you need three Benjamins to take home a 70-deg eyepiece.

It's mysterious that, among eyepiece lines where certain focal lengths are better than others, that the "dog" in the line-up is often in the ~14mm focal length (e.g. Meade 5000 UWA, ES-82, Pentax XW). That is a *critical* focal length if you've got a Dob. Your "clutch"/"money" eyepiece, for lack of a better term.

Clear Skies,
Phil

#9 Starman81

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Posted 13 October 2012 - 12:12 PM

I really hope the 14mm Delos is what everyone else expects--just as sharp as an Ethos, just with 72-deg AFOV, more eye relief, and little/no field curvature

I know what I'm about to say this isn't going to please a lot of Pentax users, but here goes--I don't quite understand why the 14XW and the 20XW were released at all at full price given their field curvature. Yes, they've got great transmission and contrast, but field curvature to that magnitude is inexcusable for the price they command.

Sure, a Paracorr cleans it up. But a coma corrector shouldn't have to clean up anything *but* coma if you need three Benjamins to take home a 70-deg eyepiece.

It's mysterious that, among eyepiece lines where certain focal lengths are better than others, that the "dog" in the line-up is often in the ~14mm focal length (e.g. Meade 5000 UWA, ES-82, Pentax XW). That is a *critical* focal length if you've got a Dob. Your "clutch"/"money" eyepiece, for lack of a better term.

Clear Skies,
Phil


I agree Phil. I recently picked up the XW 14 & 20 and find that the FC is very minor in the 20 but more prevalent in the 14, which is in agreement with other's observations. I have relatively young eyes (31) so I find that I am able (so far) to accommodate for it, but it is there. I guess it comes down to how much your eyes can accommodate for it and if that is acceptable to you.

With that being said, it puts a lot of pressure on the Delos 14. It can either join the pack as 'good but not great' or cement itself at the top as the premier 14mm eyepiece in the 68*-72* AFOV range. With its ~30% MSRP premium over the XW's, it has no choice--it better be the best!

#10 RAKing

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Posted 13 October 2012 - 02:16 PM

I know what I'm about to say this isn't going to please a lot of Pentax users, but here goes--I don't quite understand why the 14XW and the 20XW were released at all at full price given their field curvature. Yes, they've got great transmission and contrast, but field curvature to that magnitude is inexcusable for the price they command.


I guess your statement just goes to prove how different we all are. Some of my friends and I consider the 14 XW to be the best eyepiece of the line. :)

Mine is so good on double stars, it relegated my 13mm Ethos to the bench.

Life happens and I'm sorry the 14 didn't work for you as well as it (and the 20 XW) work for me.

Cheers,

Ron

#11 SeattleScott

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Posted 13 October 2012 - 02:56 PM

Not to get sidetracked, but there is always the 13mm LVW. No field curvature there (that I can see at least) and lower price than the XW and Delos with similar features and Japanese quality. But if price is not the object, or you really want 14mm, then yeah, wait for the Delos and see how it does.

#12 slack

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Posted 13 October 2012 - 03:19 PM

I know what I'm about to say this isn't going to please a lot of Pentax users, but here goes--I don't quite understand why the 14XW and the 20XW were released at all at full price given their field curvature. Yes, they've got great transmission and contrast, but field curvature to that magnitude is inexcusable for the price they command.


Or...

I know what I'm about to say this isn't going to please a lot of Tele Vue users, but here goes--I don't quite understand why the Nagler X and the Nagler Y were released at all at full price given their pincushion distortion. Yes, they've got great transmission and contrast, but pincushion distortion to that magnitude is inexcusable for the price they command.

You can also substitute color tint for pincushion distortion, or whatever you perceive as a flaw with a particular eyepiece. Btw, Pentax actually publishes the field curvature data for their eyepieces so that they might be well matched to a given scope.

#13 ausastronomer

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Posted 13 October 2012 - 06:08 PM

I know what I'm about to say this isn't going to please a lot of Pentax users, but here goes--I don't quite understand why the 14XW and the 20XW were released at all at full price given their field curvature. Yes, they've got great transmission and contrast, but field curvature to that magnitude is inexcusable for the price they command.

Sure, a Paracorr cleans it up.

Clear Skies,
Phil


Hi Phillip,

Thats drawing a pretty long bow. There have been plenty of eyepieces from numerous manufacturers, including Televue, which have been far from perfect, yet still sold at full price.

On that basis the 17mm and 22mm Televue Naglers should be more heavily discounted than the 14mm and 20mm Pentax XW's. I actually own the 14mm and 20mm Pentax XW's and the 17mm and 22mm Televue Nagler 4's and I can guarantee you that in all 3 of my newtonians when used without a paracorr the edge of field performance of the two T4 Naglers is clearly inferior to the two Pentax eyepieces. In fact it isn't even close. Granted the T4 Naglers have a larger AFOV but they still go to *BLEEP* closer to the central axis than both Pentax eyepieces.

When used with a paracorr, all 4 eyepieces perform superbly.

I also own a 13mm ETHOS and my preference is in fact to use the 14mm Pentax XW with Paracorr than use the 13mm ETHOS.

The field curvature issue of the 14mm and 20mm Pentax XW's is IMO way overplayed in a lot of cases. In my 10"/F5.3 newtonian the field curvature of the 14mm Pentax XW is barely detectable. If I tight focus on stars 1/2 way to the edge the entire FOV is very good. Sure I can tighten up the EOF or center a touch by rolling the fine focus either way but it is so minor as to not be an issue to me.

Cheers,

#14 johnnyha

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Posted 13 October 2012 - 06:36 PM

Field curvature though is different than say, pincushion. Younger eyes can usually accomodate for quite a bit of field curvature, and then most people start to gradually lose their range of accomodation as they get older. So while some people will always argue that it's not so bad for eyepiece X, it's a very real issue with many people.

#15 ausastronomer

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Posted 13 October 2012 - 06:39 PM

Field curvature though is different than say, pincushion. Younger eyes can usually accomodate for quite a bit of field curvature, and then most people start to gradually lose their range of accomodation as they get older. So while some people will always argue that it's not so bad for eyepiece X, it's a very real issue with many people.


I am 53, so my eyes aren't all that young.

Cheers,

#16 johnnyha

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Posted 13 October 2012 - 06:52 PM

You are lucky John, and that's why I said "most people". I certainly am not doubting your experience! Actually I was replying to slack's "pincushion post" above yours, sorry. But your post reinforces my point, all eyes are different. I am also 53 and my eyes are not nearly as good at accomodation. But it's still kinda like arguing that "nothing beats binoviewing" to a one-eyed person. ;) Exaggerating obviously. But accomodation for field curvature depends on individual physiology. Perhaps it is overstated as you say, but there are people who have reported it to be quite bothersome in the 14 XW and their experiences are just as valid. Anyway my original point was simply that field curvature is one aberration the effect of which truly varies from individual to individual. It can be designed out but evidently not with the 14XW.

#17 Phillip Creed

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Posted 13 October 2012 - 09:04 PM

Most people notice pincushion distortion when scanning around through the eyepiece. Field curvature, though, is something you notice at all times if you're susceptible to it.

To me, it's not the just the price the 14XW commands. Rather, it's that it was released at all given its level of field curvature. For a 70-deg eyepiece that commands around $300 new, that's a pretty serious flaw having an eyepiece that a lot of folks can't bring into focus throughout the entire FOV.

And, no, I'm not trying to dis Pentax, BTW. I've looked through several Pentax XW's and XL's, including the 14XW. I appreciate the long eye relief of both series, and their amazing contrast. Off-axis astigmatism correction is outstanding as well.

It's just frustrating knowing that the field curvature on the 14XW couldn't have been eliminated or greatly reduced in the design phase. I'm hoping Televue has done just that with the 14mm Delos. If the 14D is as sharp as the Ethos, I can see a lot of folks swapping out a 13T6 for the 14D (~same TFOV).

Clear Skies,
Phil

#18 Deep13

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Posted 13 October 2012 - 11:59 PM

Well, I notice the field curvature only on my biggest, fastest scope and only at a truly dark site. About 25% of the radius of the fov appears distorted then. I notice it when scanning around. Otherwise, it is sharp and contrasty. Having said that my TV Ploessls show just a tiny tad more on axis. The 14xw is also a very good solar H-alpha with the TV-101. I may have noticed pincushioning on my Panoptics, but I can't say for sure.

So the Delos would have to be just as good as the XW and either correct the edge distortion or be a lot lighter in weight for me to switch.

#19 ausastronomer

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Posted 14 October 2012 - 01:01 AM

To me, it's not the just the price the 14XW commands. Rather, it's that it was released at all given its level of field curvature. For a 70-deg eyepiece that commands around $300 new, that's a pretty serious flaw having an eyepiece that a lot of folks can't bring into focus throughout the entire FOV.

Clear Skies,
Phil


Phillip your missing the whole point. Straight out of the box without a paracorr the 14mm and 20mm Pentax XW's are better across 70 degrees than both the 17mm and 22mm Naglers and they cost a lot less money than either of those eyepieces. To be truthful the 17mm and 22mm Naglers without a paracorr are pretty ordinary off axis. With a paracorr they are excellent.

Cheers,

#20 t.r.

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Posted 14 October 2012 - 06:16 AM

I think alot of people miss the point of XW eyepieces...

" The XW series lenses are 1.25-inch, telescope eyepieces designed for Pentax’s 65-, 80- and 100-mm ED spotting scopes. These versatile lenses are made with the same ED glass as the scopes themselves to provide high-resolution images."

It just so happens they are darn good in other astronomical scopes. The Delos had better beat them for the money they command IMHO! :smirk:

#21 RAKing

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Posted 14 October 2012 - 07:06 AM

I think alot of people miss the point of XW eyepieces...

" The XW series lenses are 1.25-inch, telescope eyepieces designed for Pentax’s 65-, 80- and 100-mm ED spotting scopes. These versatile lenses are made with the same ED glass as the scopes themselves to provide high-resolution images."

It just so happens they are darn good in other astronomical scopes. The Delos had better beat them for the money they command IMHO! :smirk:


And to get this thread back on track -- I am very happy with my current lineup of Pentax XW eyepieces and have no plans to buy the Delos eyepieces with the same focal length (10 or 14).

I am interested in the other Delos eyepieces and hope to try out the 8mm and 12mm when they finally start shipping.

If the Delos line proves to be as comfortable to use as the Pentax, they will be very successful, IMHO. There are many of us who like comfortable, easy to use eyepieces, with what I want to call "comfortable FOV". :cool:

Cheers,

Ron

#22 RolandHeadless

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Posted 14 October 2012 - 07:13 AM

I don't know the source of that quote, but I've read Pentax spotting scope literature that suggest the opposite -- that Pentax XW "astronomical eyepieces" will also work in spotting scopes.

My impression is that the Pentax XWs were designed primarily for the astronomy market, and the zooms for the spotting scope market. The overlap in usage is a nice bonus.

#23 Jeff Morgan

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Posted 14 October 2012 - 11:39 AM

I know what I'm about to say this isn't going to please a lot of Pentax users, but here goes--I don't quite understand why the 14XW and the 20XW were released at all at full price given their field curvature. Yes, they've got great transmission and contrast, but field curvature to that magnitude is inexcusable for the price they command.


Ditto the 40XW. I had high hopes for it to supplant the 31 Nagler in my collection, but the field curvature was a killer. The outer 2/3 of the field was so bad I might as well have been using a $100 Erfle. At $500 I expected much better.

Oh well, the delivery truck travels in both directions.

#24 Deep13

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Posted 14 October 2012 - 12:59 PM

According to the Astronomics website the 14 Delos will be a bit heavier than the Pent. 14XW.

#25 johnnyha

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Posted 14 October 2012 - 01:58 PM

Perhaps the XWs 14 and 20 were made for spotting scopes and the rest were added after people started using them in telescopes?

And this is interesting, I did not realize Hoya which had bought Pentax in 2007, sold the imaging division to Ricoh last year. So these eyepieces are apparently owned and distributed by Ricoh now.






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