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They aren't pricey compared to the Delos and I prefer the XW regardless of price. It's the Goldilocks eyepiece and Televue just figured that out.

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You know, thats a good point. I wonder how many TV fanboys will be beating their chests about the superiority of the Delos design, when, in fact, Pentax figured out the perfect "Zen" of a do everything eyepiece long ago. GregN really was the "Pentax Buddah", even more so than Dr. D, and was ahead of his time in trying to get the word out. I took his advice a few years ago and glad that I did...I saw the light! I have read on CN that some Ethos pundits are dumping them for the greater transmission properties, aberration freedoms and comfort of the Delos. Hmmm...are they incidently admitting that there are some compromises in that design that many of us saw early on and didn't like? The "old school" XW's accomplished this "Zen" long ago, although the newer, modern Delos may in the end have an edge. And it should, it has the advantage of the latest technology and coatings!
I know that if I could only have one design series of eyepieces, it would be either the Pentax XW's or the TV Delos. But, fortunately in today's market, we have options.

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Not so fast on the knock on Ethos vs. Pentax XW's. I was a very early adopter of Pentax XW's following my ownership of XL's. I own them all except the 14mm up to the 30mm XW. It really depends on the types of scopes you use and especially their focal length. For my premium sub f/4 Newtonians with a Paracorr II, the Ethos ep's are much more aesthetically pleasing than the XW's for many objects. That being said, in direct comparisons between my 10mm Ethos and 10mm XW for planetary detail, the XW eeks out just a bit more detail for my eyes than the Ethos. I also enjoy the added eye relief. However, the TV Ethos are so intoxicating in large, fast Newtonians that I ended up getting every single one of them and have never had a moment of buyer's remorse. All of my refractors/reflectors can track so the FOV is not as beneficial as it is for some other folks. However, I have two eyepiece boxes, one populated with Ethos ep's and the other populated with XW's and there are times when I use both boxes and there are other times when I only use one or the other. It depends on the scope being used and the object(s) being viewed. I certainly could not make a blanket statement about either brand given the diverse uses that they provide. I also have an extra set of 5mm, 10mm and 20mm XW's for outreach with my 10" f/5 outreach Newt on a tracking platform. The reason I use the XW's in this application is that they are waterproof and have excellent eye relief and if they get "gooked up", I can easily clean them as they are waterproof. Bob

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Not so fast on the knock on Ethos vs. Pentax XW's. I was a very early adopter of Pentax XW's following my ownership of XL's. I own them all except the 14mm up to the 30mm XW. It really depends on the types of scopes you use and especially their focal length. For my premium sub f/4 Newtonians with a Paracorr II, the Ethos ep's are much more aesthetically pleasing than the XW's for many objects. That being said, in direct comparisons between my 10mm Ethos and 10mm XW for planetary detail, the XW eeks out just a bit more detail for my eyes than the Ethos. I also enjoy the added eye relief. However, the TV Ethos are so intoxicating in large, fast Newtonians that I ended up getting every single one of them and have never had a moment of buyer's remorse. All of my refractors/reflectors can track so the FOV is not as beneficial as it is for some other folks. However, I have two eyepiece boxes, one populated with Ethos ep's and the other populated with XW's and there are times when I use both boxes and there are other times when I only use one or the other. It depends on the scope being used and the object(s) being viewed. I certainly could not make a blanket statement about either brand given the diverse uses that they provide. I also have an extra set of 5mm, 10mm and 20mm XW's for outreach with my 10" f/5 outreach Newt on a tracking platform. The reason I use the XW's in this application is that they are waterproof and have excellent eye relief and if they get "gooked up", I can easily clean them as they are waterproof. Bob

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They aren't pricey compared to the Delos and I prefer the XW regardless of price. It's the Goldilocks eyepiece and Televue just figured that out.

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You know, thats a good point. I wonder how many TV fanboys will be beating their chests about the superiority of the Delos design, when, in fact, Pentax figured out the perfect "Zen" of a do everything eyepiece long ago. GregN really was the "Pentax Buddah", even more so than Dr. D, and was ahead of his time in trying to get the word out. I took his advice a few years ago and glad that I did...I saw the light! I have read on CN that some Ethos pundits are dumping them for the greater transmission properties, aberration freedoms and comfort of the Delos. Hmmm...are they incidently admitting that there are some compromises in that design that many of us saw early on and didn't like? The "old school" XW's accomplished this "Zen" long ago, although the newer, modern Delos may in the end have an edge. And it should, it has the advantage of the latest technology and coatings!
I know that if I could only have one design series of eyepieces, it would be either the Pentax XW's or the TV Delos. But, fortunately in today's market, we have options and I love using a little bit of everything.

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I think my posting history shows that I'm not a TV fanboy. I've been quite critical of certain aspects of TV eyepieces. But I do think TV nailed it with the Delos eyepieces based upon my experience with the 10mm Delos.
And I do think that the Delos is better than the XW for reasons that have nothing to do with coatings.

I've owned every XW from 7mm to 40mm. The 20mm and 40mm were my favorites. At the time I had the 20mm XW I tried the 17.5mm Nikon NAV out. The Nikon NAV was better than the 20mm XW in several regards. First, the stars were sharper pinpoints. Second, there was absolutely zero issues with blackouts - including when barlowed.

With XW's there are very minor blackout issues that grow with barlowing. For lunar observations the 17.5mm Nikon NAV barlowed with a 3x TV barlow was absolutely the best eyepiece I've ever used. Precision sharpness of the view, no blackouts, no glare. When I barlowed the XW's for lunar observations it was not as sharp. Details were definitely crisper with the NAV.

The 17.5mm Nikon NAV was essentially perfect except for one thing - there was fairly significant edge of field brightening- which really ticked me off given it was a $520 eyepiece. The XW's have milder edge brightening - enough that I feel it saps away some of the contrast of the view with deep sky objects.

Enter the Delos. I found that the 10mm Delos brings to the table all the great qualities of the Nikon NAV without the edge of field brightening. It is essentially perfect. It is as sharp as the Nikon NAV. It is as free from blackouts as the Nikon NAV. It barlows without blackouts appearing. And it is sharp to the edge with no edge of field brightening.

So that is my take. I loved the XW's, but I think the Delos is better. And I'm no TV fanboy - the Delos is the only TV eyepiece that I have ever wanted to keep. The only reason I sold the 10mm Delos was that I knew the 17.3mm was coming out and would get a lot more use.

Dave

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The 17.5mm Nikon NAV was essentially perfect except for one thing - there was fairly significant edge of field brightening- which really ticked me off given it was a $520 eyepiece. The XW's have milder edge brightening - enough that I feel it saps away some of the contrast of the view with deep sky objects.

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With XW's there are very minor blackout issues that grow with barlowing. For lunar observations the 17.5mm Nikon NAV barlowed with a 3x TV barlow was absolutely the best eyepiece I've ever used. Precision sharpness of the view, no blackouts, no glare. When I barlowed the XW's for lunar observations it was not as sharp. Details were definitely crisper with the NAV.

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As far as blackouts go with the XW's and barlows, I just raise the eye cup to the desired level and there are zero blackouts, plus a TV Powermate does not increase the ER on eyepieces, so it would not happen at all with a long ER EP and a powermate!

As far as the Delos being superior to the XW....I don't agree at all. I think they are BOTH incredible eyepieces. I traded my 6mm Delos for the 7mm XW for lower power and a slightly larger field......plus I found the XW easier on the eyes....three people agreed that the Delos had a different feel than the XW, but they are still both excellent EP's!

I am interested in the 14mm Delos myself! I wanted a 14mm XW / XL, but the FC sways me towards the 14mm Delos!...I would rather get used to the Delos being that it has a different "feel" than the XW because more than likely, the 14mm Delos will have no FC.

Cheers,

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The 17.5mm Nikon NAV was essentially perfect except for one thing - there was fairly significant edge of field brightening- which really ticked me off given it was a $520 eyepiece. The XW's have milder edge brightening - enough that I feel it saps away some of the contrast of the view with deep sky objects.

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Dave,

You have reported "edge of field brightening" with hordes of eyepieces. I had some of the ones you mentioned and could not see it. Maybe it's your scope? Maybe it's your skies? Whatever it is, I have not seen it!

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Hi Markus,

I've reported it with eyepieces that show it at any level that attracts my attention. To summarize the list that has shown it:

42mm GSO superview (strong) - reported by others too.
17.5mm Nikon NAV (moderate)
Pentax XW's - milder than NAV but noticeable
Pentax XL's - a little more than the XW
14mm Denkmeier (strong) - could be traced directly to highly reflective annodizing
8mm and 17mm Vixen LVW (very mild)
19mm Celestron Luminos (moderate)
8.8mm Meade 5000 UWA - very mild
12mm Celestron X-cel LX - (moderate) - other users have reported this as well.
14mm Meade UWA smoothside (mild-moderate when skies are have a lot of scatter, very mild when skies are highly transparent, non-existent when barlowed).

Those that have not shown any edge of field brightening:

27mm TV Panoptic
17mm TV T4 Nagler
22mm Vixen LVW
10mm TV Delos
Celestron Vixen Silvertop plossls
Meade smoothside plossls
Brandons

That is not a complete list, but it hits the ones that jump out at me at the moment. It is internal to the individual eyepiece and I believe it comes from poor scatter control on internal surfaces. How can it be my scope or my skies when I see it with some widefield eyepieces but not others?

I tried addressing it when I had the 17.5mm Nikon NAV with the following efforts: Flocking of the dewcap and internal surfaces and repainting the focuser drawtube on my refractor. That did nothing. I tried switching diagonals and flocking diagonals. Did nothing. I tried observing straight through - did nothings.

Keep in mind that if I see any change in the blackness of the sky background across the field of an eyepiece consistently I am reporting that eyepiece as exhibiting edge of field brightening. It doesn't necessarily mean the eyepiece has a "bright" background at the edge - although the 42mm GSO and the 14mm Denk did. It just means that the background is not uniform.

I cannot report a single TV eyepiece that has this problem. So I'm inclined to place the blame on individual manufacturers failing to properly baffle and blacken internal surfaces.

Dave

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Don,

1) The 4 longest XWs--40/30/20/14 have positive field curvature. In short focal length dobs used without a Paracorr, this field curvature may be noticeable because it will add to the same sign of field curvature in the scope.

How does the curvature of these longer focal length XWs react to an f7 refractor . . . say, the TEC 140?

Thanks,
Brent

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Don, FYI, for some of us, the 14mm in both the XL and XW versions has had WAY too much field curvature for taste and is not sufficiently damped by a Paracorr I or Paracorr II. The 20mm Pentax XW has always been just at the threshold of me not liking it but is good enough where I have used it frequently because of the parfocal issues with the other XW's and the overall color-neutral presentation and excellent throughput. I use both slow and fast refractors and reflectors and the 14mm is just not usable for my perceptual system. As you mentioned, the 3.5-10mm ep's are spot on! The 30mm XW is not bad but I enjoy my 31mm Nagler as much or more and love the 21mm Ethos to death! Bob

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This is interesting...and makes me think that lens prescriptions might have changed. I purchased a used 20mm XW and like you characterize, it is almost at the threshold of me not liking it but is so good otherwise that it is a keeper. And I use it in both fast and slow scopes. So we have the same reaction to the eyepiece.

Now for the 14mm XW I decided to purchase that one new. It shows incredibly little FC, even in my Dob. So makes me curious with all the reports on the 14mm as having a lot of FC...for me mine has about 1/3 of what the 20mm shows.

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Bill

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The points DonP brought up encourage me to try a pair of Delos for binoviewing...now which focal length?

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