87 replies to this topic

[iKMN]

I've considered the Ethos, especially as it weighs the same as the Delos. That bothers me. New price is not an option.  I just put out a wanted ad, you never know, you're not gonna catch any fish if you don't cast the line. I also have a wanted ad for a 3.5mm Delos, but no bites so far in 3 weeks.  The Ethos would make a sensible progression to my Morpheus with its FOV. 

 

Definitley consider the Ethos.  I've had both the Delos and XWs.  I prefer the XWs but both are excellent and as others say most people have a hard time seeing any difference. Having a case full of XWs or Delos you have some of the best eyepieces around. I only prefer XW over Delos because it was more comfortable for me.  But I moved on from my XWs because my most used scopes are my small refractors and ergonomic wise a Pan 24 and the T6s work better "for me".  But I am thinking a long the same lines as you that for my bigger scopes I might as well get Ethos over XW or Delos because the size/wt is relatively the same and you get 100 AFOV.  The 15mm eye relief is perfect for non-glasses.  I only have the 17E right now but I'm working on the rest.  Not cheap but worth it.  

[TayM57]

Visual astronomy will have to last another 50 years, and I'm not so sure it will.

It will.

[oatmeal]

Took advantage of some pretty good seeing here just after sunset and a 6 day old moon (maybe my favorite lunar age, for its dramatic views of Theophilus)

 

Spent time comparing the 3.5 XW and 3.5 Delos in my 12" Dob with Paracorr in place (guest appearances also made by the 3.5 XWA and 4 LHD). 

 

Tonight, I preferred what the XW was showing me. In their best moments, both were super sharp, more limited by seeing, I think, than anything. However, the Delos has a funky quality to its presentation that I'm having difficulty cogently verbalizing: it seems to have a slightly more watery, nervous, jittery character to its views. It's not just the turbulence of seeing coming through, but something in the optics of the eyepiece which are seemingly additive to the seeing. I did half a dozen repeat A/B comparisons vs the XW, and though all of the same challenging craterlets were eventually identifiable in both pieces, they were consistently more readily acquired and more easily maintained in the XW. Both were excellent, and the difference was subtle, but the XW had the edge.

 

At its best, the Delos may have a smidgen more contrast than the XW, though it's very close. The XW seems to have more neutral color, while the Delos certainly skews a little warmer with a soft amber cast.

 

Not entirely germane to this comparison, but I have reaffirmed my affection for the 3.5 XWA/Lunt, especially for lunar viewing. It's not perfect: there's probably some wash-out/contrast loss vs the sublime Pentax XW, but it's still impressively sharp, with tame ergonomics for a hyperwide, and by my lights a somewhat steadier presentation than the Delos. In above average seeing, skimming the lunar surface with a 110° field at 430x really is something special.

[oatmeal]

Oh, and getting absolute best focus seemed more challenging with the Delos. It was easy to get close to best focus, making my eye strain and twitch to accommodate, but sharpest focus entailed some hunting, hoping to get lucky and get it right. The XW was easier to snap to a clear, forgiving focus point; the XWA easier still.

Edited by oatmeal, 13 June 2024 - 01:13 AM.

[SeattleScott]

I noticed that shimmering effect when comparing a 5LVW to a 5LE. Like you I didn’t really know what to make of it. My only thought was the LVW is a much larger eyepiece, and maybe there was some sort of cool down issue going on inside the eyepiece. I know the Delos is a little larger but doesn’t seem substantially larger than the XW.

[PJBilotta]

I love the 17.3-12 Delos, but from 10mm on down, I find the XWs best them. The 10 and down Delos might have a slight edge in contrast and correction, but I consistently find I can tease out finer detail and faint nebulously in the 10, 7 and 5mm XWs than comparable Delos or Morpheus.

I can't speak for the 3.5mm, as I don't have any use for one.

[oatmeal]

Yes, I was curious if I was missing anything, as I do note some flaws in the XWs, e.g. chromatic aberration near the edge of field, a bit of mild EOFB in light-polluted skies. But the gestalt of the XWs may still win out over the Delos, for my use anyway. I have high regard for my 14 Delos, which has led to my recent acquisition of the 10 and 3.5 Delos, as well as an inbound 6mm. I'll need a few truly good dark, steady nights over the next few months to develop a fully formed opinion (and the return of some planetary targets), but I'm open to the possibility of either line besting the other. Some of my recent comparisons have reaffirmed in my mind just how excellent the 10-3.5 XWs are though, so the bar for the Delos is rather high.

[gnowellsct]

Yes, I was curious if I was missing anything, as I do note some flaws in the XWs, e.g. chromatic aberration near the edge of field, a bit of mild EOFB in light-polluted skies. But the gestalt of the XWs may still win out over the Delos, for my use anyway. I have high regard for my 14 Delos, which has led to my recent acquisition of the 10 and 3.5 Delos, as well as an inbound 6mm. I'll need a few truly good dark, steady nights over the next few months to develop a fully formed opinion (and the return of some planetary targets), but I'm open to the possibility of either line besting the other. Some of my recent comparisons have reaffirmed in my mind just how excellent the 10-3.5 XWs are though, so the bar for the Delos is rather high.

I think the preferred term for off axis color in an eyepiece is lateral color. If it were chromatic aberration it would be like an achromatic refractor and you would see the color, even multiple colors, on any bright thing you looked at anywhere in the field. If I am wrong I'm sure someone will correct me.

The delos is what I would use if the xws did not exist but they do exist. When I went through my 16 mm and 17 mm testing phase, probably the only time I bought a bunch of eyepieces and compared them, in the Delos was a strong contender. But I went with the Nikon.

I had something like $2,000 in 17 mm eye pieces during that phase. But sold off most and recovered my funds. The 16.5 Pentax came out some years later. Had it existed, I probably would not have had the contest at all, I was trying to fill a gap in the Pentax line.

As with most of the Televue lines I had problems with blackout. Not as bad as some of the older options though.

Greg N

[oatmeal]

Similar experience again tonight in good-to-very-good seeing utilizing my 4" refractor in the neighborhood of Eratosthenes. Beyond the effects of seeing alone, details in the Delos 3.5 just seemed a bit more watery/wavy/jiggly/uncertain than those in the 3.5mm XW or 4mm LHD; though a similar level of detail was discernible in all 3 pieces, it was more quickly settled upon in the XW & LHD.

 

I also compared the recently arrived Delos 6 to my 6 LHD and the Ethos 6, as well as the bracketing 5 & 7 XWs, where the same phenomenon was at play. The Ethos, LHD, and XWs seemed to have more steady presentation of details than the Delos. I don't think this is just a psychological projection on my part. I cycled back and forth for about an hour and a half between these five pieces, and each time the Delos 6 was in the focuser, I struggled slightly to tease out and keep hold of the details I knew were there. The Ethos was probably the sharpest of the bunch; the XWs the most comfortable to use; the LHD not far behind in either sharpness or comfort. At certain angles & alignments of the exit pupil, the LHD suffered from reflections of the bright moon in the concave eye lens, but nevertheless retained sharpness and excellent contrast. These reflections were tamed when using an ND moon filter, but I preferred the views without the filter, so dispensed with it for the majority of tonight's session.

 

The Delos are rather warm in tone to my eyes, a characteristic they share with the LHDs. The XWs and Ethos were noticeably cooler/neutral.

[ABQJeff]

I have both the Pentax 3.5 XW and TV Delos 3.5. Count me as another one who prefers the 3.5 XW. While the optical performance between these two EPs is very close, it is the ergonomics of the XW line that I really prefer over Delos.

The whole TV loosen and lock eye cup adjustment seems too difficult to use and keep set (especially in the cold). Meanwhile the XWs more intuitive “stiff rotating” eye cup adjustment just works and barely moves use after use (and you can adjust it with one hand when EP locked in an eyepiece clamp).

Due to this I rarely use my two Delos (3.5 and 12).

[Starman1]

I have both the Pentax 3.5 XW and TV Delos 3.5. Count me as another one who prefers the 3.5 XW. While the optical performance between these two EPs is very close, it is the ergonomics of the XW line that I really prefer over Delos.

The whole TV loosen and lock eye cup adjustment seems too difficult to use and keep set (especially in the cold). Meanwhile the XWs more intuitive “stiff rotating” eye cup adjustment just works and barely moves use after use (and you can adjust it with one hand when EP locked in an eyepiece clamp).

Due to this I rarely use my two Delos (3.5 and 12).

Why not identify where the eyecup needs to be set for you on the Delos and then lock the eyeguard in place at that position (use two hands and really tighten)?

Then, you wouldn't need to adjust them at all from that point forward.

I did that with Delites and the only issue there was that the bottom caps were too tight.  But, as I recall, they aren't that tight on the Delos.

[ABQJeff]

Why not identify where the eyecup needs to be set for you on the Delos and then lock the eyeguard in place at that position (use two hands and really tighten)?
Then, you wouldn't need to adjust them at all from that point forward.
I did that with Delites and the only issue there was that the bottom caps were too tight. But, as I recall, they aren't that tight on the Delos.

Hi Don, I tried that and it just didn't hold well, especially after a couple uses, so then I would be back at the scope ‘tuning the top’ with two hands instead of just using my scope…maybe it requires more practicing. But one shouldn’t have to practice to use an eyepiece. My Morpheus, Pentax, ES, AT/SV, Tak EPs aren’t so finicky.

The Delite mechanism isn’t great either BUT it is my only 3mm (and one of my best planetary EPs) so I deal with it.

[payner]

Interesting, my Delos are adjusted for me and hold with no issues. It was easy to tighten them, twisting with both hands.

[ABQJeff]

Interesting, my Delos are adjusted for me and hold with no issues. It was easy to tighten them, twisting with both hands.

Guess I have to practice more. :-/

[payner]

[oatmeal]

I do adjust the Delos eye guards to where they're perfectly positioned for me and tension the mechanism tightly, but they still often manage to slip when replacing end caps or just putting them back into their slots in a foam case. The Delos mechanism is okay, but the XWs are just better - it's impossible to make them slip.

[CrazyPanda]

I do adjust the Delos eye guards to where they're perfectly positioned for me and tension the mechanism tightly, but they still often manage to slip when replacing end caps or just putting them back into their slots in a foam case. The Delos mechanism is okay, but the XWs are just better - it's impossible to make them slip.

When I had Delos, and when my DeLites were still cloaked, I would always lower the eye guard to the lowest position since they took up less room in the case and I could fit more gear in.

 

Setting the rough height was a form of muscle memory that would happen as I lifted the eyepiece from the case to the focuser.

 

But what I've learned is that brightness of the target influences where I like to put the eye guard. For deep sky, my pupils are dilated, and I find the effective eye relief to be greater than when they're constricted and looking at a bright object. So I would set the eye guard a bit higher for deep sky than for lunar or even planetary viewing. Making adjustments with the Delos/DeLite eye guards is easy.

Pentax XW requires about 2-3 turns between "lunar mode" and "deep sky mode" for me.

 

I would say the ability to collapse the eye guard to the lowest point to save space, and the ability to make rapid adjustments, gives the Delos/DeLite approach the UX edge over the XW approach. But on the flip side, the XW eye guard can be adjusted with one hand.

[HellsKitchen]

I have an opportunity to buy a Pentax 3.5mm XW for AUD $350, used and as new condition from a dealer. Tempted to pull the trigger. 

 

I don't think I'll ever find a used 3.7mm Ethos, and a new one costs $1,299 locally, which is absolute malarky and not worth consideration.  A new Delos is also $769, which is also Malarky and  beyond the realm of sanity. 

Edited by HellsKitchen, 25 October 2024 - 07:54 PM.

[Starman1]

I have an opportunity to buy a Pentax 3.5mm XW for AUD $350, used and as new condition from a dealer. Tempted to pull the trigger.

I don't think I'll ever find a used 3.7mm Ethos, and a new one costs $1,299 locally, which is absolute malarky and not worth consideration. A new Delos is also $769, which is also Malarky and beyond the realm of sanity.

It would be cheaper to buy Tele Vue from the U.S. and pay shipping.

[HellsKitchen]

It would be cheaper to buy Tele Vue from the U.S. and pay shipping.

 

I crunched the numbers, and I won't really be gaining anything. Even from the US, that 3.7mm Ethos is gonna be well over AU $1,100. I just keep getting stooged on the shipping, paying $100 US for posting an eyepiece. Even the base price in the US, when converted, is $1000 AUD.  And plus, when the value is over $1000 AUD, I'm gonna get done for tax and import duties. Happened to me when I ordered a trifecta of Morpheus from FLO. Lesson learned. 

Edited by HellsKitchen, 26 October 2024 - 07:18 PM.

[HellsKitchen]

Well, I decided to bite the bullet and order the Pentax 3.5mm. US $243 shipped, snap up this deal while it lasts, last eyepiece in stock too. Don't have much to lose I figure. Ain't gonna come across any reasonably price Ethos or Delos any time soon it seems. 

Edited by HellsKitchen, 25 October 2024 - 09:11 PM.

[csrlice12]

And the 3.5XW is a fine eyepiece.

[25585]

Interestingly its not got an XL predecessor. I have a Vixen LVW 3.5mm which is fine, but not used much.

[ji4m]

I have both the Pentax 3.5 XW and TV Delos 3.5. Count me as another one who prefers the 3.5 XW. While the optical performance between these two EPs is very close, it is the ergonomics of the XW line that I really prefer over Delos.

The whole TV loosen and lock eye cup adjustment seems too difficult to use and keep set (especially in the cold). Meanwhile the XWs more intuitive “stiff rotating” eye cup adjustment just works and barely moves use after use (and you can adjust it with one hand when EP locked in an eyepiece clamp).

Due to this I rarely use my two Delos (3.5 and 12).

This is where I am.  I want a 3.5mm extension to my Morpheus EPs.  I bought a used Delos.  Fantastic view, but it feels "demanding" on eye placement distance.  I continually adjust the eye cup.  When I get it perfect (if ever), I am going to hot glue it in place.  I have accidentally shifted the eye cup while taking the EP out from the case foam.  Perhaps the 3.5 XW will better fit my use model.  I haven't tried it yet.

I comfortably use a Meade 14mm UWA smoothie, so I have experience with exacting eye placement.

[Starman1]

This is where I am.  I want a 3.5mm extension to my Morpheus EPs.  I bought a used Delos.  Fantastic view, but it feels "demanding" on eye placement distance.  I continually adjust the eye cup.  When I get it perfect (if ever), I am going to hot glue it in place.  I have accidentally shifted the eye cup while taking the EP out from the case foam.  Perhaps the 3.5 XW will better fit my use model.  I haven't tried it yet.

I comfortably use a Meade 14mm UWA smoothie, so I have experience with exacting eye placement.

Remove the Delos eyecup and clean the barrel and collet with alcohol.

Reassemble.

Once you've found the right placement for the eyeguard in the field, note the line on the side of the eyepiece that corresponds to your perfect position in case the eyeguard moves.

Remove the eyepiece from the focuser and "gorilla tighten" the two parts of the eyecup using both hands and a lot of strength.

I experienced this movement on the Delites (same eyeguard design) until I did this, and the eyeguard got tight enough it would have taken a hammer to move it.

 

There may be a machining variance from eyepiece to eyepiece, but after I did this I could even remove the super-tight Delite bottom caps without moving the eyeguard.

I did, however, change the bottom eyecaps on the Delites because they were just too tight.  A cap should come off easily, yet stay on.

I think rubber caps go on and off more easily, but they also tend to be looser, and not stay on well.  Plus, rubber caps on the bottoms can be pressed into contact with the bottom lens in the eyepiece,

so they are not desirable for eyepieces with lenses close to the bottom of the eyepiece.