ES82° or Nagler T4 or Delos

[slickfonzy]

I am looking to make my first foray into the world of "premium" eyepieces, by which I mean my first eyepiece that I will have purchased separately from a scope.  I have a Revelation 10-inch f/5 dob, for which I have been using the Revelation 9mm Plossl and the 30mm Superview.  To start with, I have been looking at something around the 11mm or 12mm mark, which should give me useful options unbarlowed and barlowed.

To this end, I have been considering the ES 11mm 82°, the 12mm T4, and the 12mm Delos - I will cautiously say that budget isn't a problem, although I will have to justify the cost to my wife, so the cheaper the better, hence why the ES is in the list!  However, I've been going round in circles for so long now that I get a headache at the thought of trying to decide 

My main constraint is my astigmatism for which I need correction while observing, so my questions probably come down to:

• Is the 15.6mm eye relief on the ES likely to be too tight for glasses?
• If so, will a TV Dioptrx fit the ES, and if so will the eye relief be sufficient for that?
• If the ES is out of the question, will the 17mm eye relief on the T4 be OK for glasses?
• If not, should I go for the T4 with Dioptrx, or the Delos with glasses?

Apologies for asking so many questions, and I appreciate that the answers are probably subjective, but any input will be most appreciated! 

[Louis D]

Skip the ES-82 line unless you can find the older 30mm ES-82 with the flush mounted eye lens (also sold as the Meade 5000 UWA and Celestron Axiom).  The rest just don't have enough eye relief and the eye lens is inexplicably recessed.

The 12mm and 17mm Nagler T4s are usable with eyeglasses, but tricky to hold the view.  Both are sharp across the field with no kidney-beaning.

The Delos and Pentax XWs are easy to hold the view with eyeglasses and are incredibly well corrected across the field (only 10mm and below for XW due to 14mm and 20mm having field curvature).  I'd give the edge to the Delos line.

The new Baader Morpheus line is supposed to be superb other than their fuzzy field stops and flimsy, nonadjustable eyecups.

There's also the new ES-92 line that I'm considering to replace my T4s with.  They're supposed to be superb with an XW/Delos-like eyeglass experience.

If you can find them used, the Vixen LVW line is just a notch below the XW/Delos lines, but overpriced new.

The TV DeLites are praised as being superb at 62 degrees, edging even the Delos line.

[jetstream]

The recessed eyelens might cause you problems with the ES, its hard to beat a Delos for all around viewing experience.

[Louis D]

2 hours ago, jetstream said:

The recessed eyelens might cause you problems with the ES, its hard to beat a Delos for all around viewing experience.

Not only recessed, but geometrically, you need at least a 30mm eye lens diameter to see an 82 degree field with a mere 16mm of usable eye relief (the absolute minimum I've found).  It's tight on the T4s for this reason.  The only ES-82 with an eye lens that big is the 30mm, thus the only one usable with eyeglasses.

The Delos (and XWs) all have 35mm eye lenses and 72 (70 for XW) degree fields of view.  As a result, there's eye relief to spare, thus the comfort level with eyeglasses.

[slickfonzy]

Thank you both for your replies.

32 minutes ago, Louis D said:

Not only recessed, but geometrically, you need at least a 30mm eye lens diameter to see an 82 degree field with a mere 16mm of usable eye relief (the absolute minimum I've found).  It's tight on the T4s for this reason.  The only ES-82 with an eye lens that big is the 30mm, thus the only one usable with eyeglasses.

This is interesting, so presumably even if the Dioptrx is compatible with the ES-82, there still won't be enough eye relief to see the full field.

I guess that leaves the T4s, which have the 82° field but might need the Dioptrx for more comfortable use, or the Delos with a slightly narrower field but easy to use with glasses.  Thanks for helping me narrow it down, a choice of two is much easier!  I'm leaning towards the Delos mainly for cost (cheaper than T4 + possible cost of Dioptrx).

Thanks again.

[Paul73]

Delos all the way with your scopes and eyepiece requirements. They have a very neat adjustable locking eyecup so that you can set the effective ER exactly to your needs.

I have 3 and consider them the most comfortable that I have used.

Paul

[Louis D]

If you're in the UK, the new Baader Morpheus are a cheaper, but very viable alternative to the Delos.  They have been favorably reviewed on both sides of the pond.  They yield a 76 degree field with the same size eye lens as the Delos, so slightly tighter eye relief.  The main complaints have been that their field stops are slightly fuzzy and the eyecups are flimsy and nonadjustable.

[jetstream]

The Delos are a step up in evolution from the Naglers IMHO, they have some seriously good coatings and glass. Another eyepiece that does intrigue me is the 10mmXW, rumored to be one of the best DSO eyepieces if it matches ones scope...

[Louis D]

1 minute ago, jetstream said:

The Delos are a step up in evolution from the Naglers IMHO, they have some seriously good coatings and glass. Another eyepiece that does intrigue me is the 10mmXW, rumored to be one of the best DSO eyepieces if it matches ones scope...

The Delos are definitely sharper and easier to use than the T4 Naglers, but that 82 degree field is a bit more immersive, yet somewhat tiring on the eye to hold.

I find the XWs a bit harder to hold the view in than the Delos, possibly because the eye lens is recessed 3mm for no particular reason.  I find the older XLs to be much more comfortable than the XWs in this regard because their eye lenses are mounted flush to the top.  It's just that they have a 65 vs 70 degree field and a slightly lighter sky background.

[Charic]

On 7/8/2016 at 16:16, slickfonzy said:

............My main constraint is my astigmatism for which I need correction while observing..............

With regards to slickfonzy's  comment,  do you  still need glasses with a Dioptrx fitted Delos ?

It was my assumption that the 20mm of  eye relief afforded by the Delos was an ideal option for  any spectacle  wearer.  I have prescription glasses that I don't wear at the eyepiece,  knowing that focusing alone fixes my myopia, and have been,  thus far, happy with the images I see, but there are still the odd times where I think maybe it could be my eye that is at fault concerning the sharpness/contrast in resolving the image,  to the extent that my eye feels like it's still trying to get more from the image, could this be my astigmatism?  and reading more today, on the DIOPTRX™ page, it would appear that the Dioptrx  could improve my  1.00 dioptre astigmatism.

Has anyone tried or still using this method, and is there a difference worthy of the upgrade to dioptrx? 

[slickfonzy]

Thanks to everyone for the replies, I'm settling on the Delos now 

3 hours ago, Charic said:

 do you  still need glasses with a Dioptrx fitted Delos ?

The Dioptrx is intended to correct for astigmatism so that you don't need your glasses for observing.  I suspect that for eyepieces where eye relief is tighter, such as the T4s, it makes eye placement easier than with glasses; I guess with Delos this is less of a problem.  However, I'd also be interested to hear of people's experiences with Dioptrx + Delos, and whether it's any better than using glasses.

[michael.h.f.wilkinson]

I have the full set of T4s and they are fine, especially the 22 and the 17. I also have the 14mm Delos, which is great, and definitely a touch better than the 12T4. I may well replace the latter with a Delos 12mm.

[F15Rules]

If budget allows, the Delos makes good sense.

As it doesn't for me, I went for the Morpheus 14mm and am delighted with it. And the field stop in mine is NOT fuzzy! I replaced my XW14 with the Morpheus and much prefer it on all counts.

The eyecup rubber is a little thin but ok..for interest I swapped the eyecup of my ES24mm 68 with the Morpheus one, and it fits nicely (the Morpheus one also fitting the ES eyepiece of course..there is actually not much difference in the two in use.

Good luck with your choice..for £149 brand new for an excellent 76deg eyepiece I am well pleased indeed : -).

Dave

[michael.h.f.wilkinson]

I sold my Morpheus 14 mm, as the stars were not entirely sharp at the edge (seemed to be field curvature). This may be a personal thing, as I seem particularly sensitive to it. If they had reduced the field stop to 70° I would probably have kept it. The inner part of the FOV is excellent. The Delos 14 is pin sharp to the edge. 

[slickfonzy]

Thank you both for the further feedback, I did settle on the Delos in the end, my first one should be arriving today 

When thinking about building a set I felt that the 10mm and 14mm would probably be more useful than the 12mm with my scope, so I've ordered the 10mm to start with.

[F15Rules]

4 hours ago, michael.h.f.wilkinson said:

I sold my Morpheus 14 mm, as the stars were not entirely sharp at the edge (seemed to be field curvature). This may be a personal thing, as I seem particularly sensitive to it. If they had reduced the field stop to 70° I would probably have kept it. The inner part of the FOV is excellent. The Delos 14 is pin sharp to the edge. 

I suspect that Baader went for the wider field to compete with the Nagler and ES 80+ deg ranges.

As I use a driven EQ mount I tend to view for the vast majority of the time in the centre, where the 76 deg field does frame backgrounds very nicely. And in my F7.7 ED frac I'd say only the very last 2-3 degrees shows any aberrations, and then only on very bright stars like Vega, where a slight blue "spike" pointing inwards could be seen (lateral colour?). But the double double Epsilon Lyrae showed 2 beautiful points (not split at x56 in my scope), right to the edge.

If Baader had settled for "just" 72 degrees as for the Delos, I think the comparison would have been very very close..

Congratulations on the incoming Delos, do let us know how you find it:-).

Dave

[Louis D]

I've never bought a Dioptrx because of the following:

1. High cost of about $100 per eyepiece to add.  Could be moved from eyepiece to eyepiece, but it isn't quick or simple to do.

2. Can only add to certain compatible eyepieces.   If it was mounted on the filter threads, it would be a different story.

3. Won't help with short eye relief, wide field eyepieces where you need it most because it needs about 15mm of usable eye relief minimum.  Again, if it was mounted on the filter threads, it would be a different story.

4. Messes up sharing the view with viewing partners or at public star parties who don't have the same correction as you.  If the correction was variable, it could be tuned for each observer, but it isn't.

5. Even without Dioptrx, not wearing your eyeglasses at the eyepiece when sharing the view forces others to refocus even if they are wearing eyeglasses because not everyone's native vision is infinity corrected.  Novices in particular are reluctant to touch the focuser for fear of breaking something or messing up the aiming and therefore settle on an out-of-focus image without realizing it.

5. Have to buy new Diotrx whenever eye's astigmatism correction significantly changes.  For me, that's about 1/4 diopter every 5 years.  Over the last 35 years, I've gradually gone from practically no astigmatism to 2 diopters.  I typically use dedicated astronomy glasses that I have to change the lenses in about every 5 years for less than $50 to keep up.  Toward the end of a prescription, I curse at my eyepieces for having slight astigmatism in the center until I realize what's going on and swap in my daily wear eyeglasses for a quick peep as confirmation.

6. Never noticed quality eyeglasses decreasing contrast or increasing reflections.  In regards to the latter, if there is enough ambient light that reflections off your eyeglasses are an issue, it's usually also an issue with the eye lens of the eyepiece unless you have a good, tight fit of the eye guard into your eye socket.  If so, you're likely to get fogging, eyelash goo on the eye lens, or shift the aim if it's an undriven scope.  I have noticed spurious lateral color when looking at an angle through my eyeglasses at the edge of field in ultrawides.  I correct this by tipping my head to realign my glasses with my line of sight.  I don't know if Dioptrx can overcome this on ultrawide fields since it is rigidly aligned to the eyepiece's optical axis, not to your eye's optical axis like a contact lens would be.

For all of the reasons above, I restrict myself to long eye relief eyepieces.

[alan potts]

I have had most of the Televue ranges apart from the latest De-lite. Personally I found Delos excellent and a joy to use and would say they hold a slight, and I stress slight edge over Naglers. So that would be my choice. As one member also said the Pentax XW are also good though for me 10mm and below are the jewels in the crown.

Alan

[astronymonkey]

I have the three nagler t4 eyepieces plus a couple of delos for higher powers and would say the delos have the edge when it comes to viewing comfort. T4 and delos both are fine with glasses and a joy to use with easily enough eye relief to be able to see the full field. With older and cheaper designs I often found higher power meant a dimmer and grainier image with very tight eye relief but the delos has changed this for me completely and moving from 12mm t4 up to 8mm delos even seems to give an improvement.

 

You will love the delos, great choice.

 

Cheers

[slickfonzy]

I've had a chance to get out under clear skies a couple of times this week, and so far I'm in love with the Delos (although my wallet has gone to hide in the corner)!  Without the adjustable eye guard I think it would be hard to hold the view, but once I'd worked out where to put the eye guard for use with my glasses it was so easy to use.  The way the eye guard adjusts is also very easy, and the markings on the barrel have made it a two second job to change between my setting for use with glasses and fully extended for my wife to use without.  Once the Moon has disappeared I will try it under darker skies and write a longer review for the review section, but a quick peek at M13 under the full Moon has already shown me more detail than I've seen before 

[AstroSylv1]

Don't forget the great eye relief and comfort of the Nagler 22 T4, very easy to use, great immersion 

[Piero]

The delos are great eyepieces for both comfort and view quality. To me they are a bit better that Naglers T6 as far as optical transmission. Last spring my Delos 8mm allowed me to spot all the Messier galaxies in Virgo with a mere 60mm aperture under ~19.5 mag skies. No other eyepiece (Vixen SLV, Nagler T6) I have tried went so deep. For planetary targets, the only other eyepiece which I found matches the details provided by the Delos (although tints are different), is the Vixen SLV, whose optical quality is generally considered at the level of Pentax XW. All this on and off axis.

Of course there are better eyepieces than the Delos, but the quality of the latter is very high and far cheaper than the very top. Also, considering the sky in the UK, differences might not even be noticeable. As far as comfort concerns, the Delos and Pentax XW are among the best out there I would say. 

So I think you made a very good choice and a 10mm is also a great match with your telescope.

A fine 24-28mm 68-82 deg as low power, and either a top barlow 2x to get a 5mm from your 10mm or a Delos 6mm/4.5mm as high power, might be all what you need with your telescope.

Have fun!

[Charic]

15 hours ago, slickfonzy said:

I've had a chance to get out under clear skies a couple of times this week,

I wish!........... my weather and conditions are far from perfect this season, so taking a few days out  to settle a few household chores,  but  hopefully  if the weather allows,  I may get a peek through the scope, but my  night skies are still very bright  for any serious comparison tests,  it feels  and looks like April outside, with the showers to prove it!
Enjoy the new Delos.

[alan potts]

Congratualations on you new eyepieces and good see the weather was kind to you.

The eyeguard system on the Delos is really a selling point in my books, it is a big step up in design from the Radian system, some of mine almost colapsed under their own weight when I had a few of them, others were fine.

Alan

[slickfonzy]

7 hours ago, Charic said:

I wish!........... my weather and conditions are far from perfect this season, so taking a few days out  to settle a few household chores,  but  hopefully  if the weather allows,  I may get a peek through the scope, but my  night skies are still very bright  for any serious comparison tests,  it feels  and looks like April outside, with the showers to prove it!
Enjoy the new Delos.

I probably shouldn't say this on here, but I'm hoping for some rain, it's been hot and dry down here for as long as I can remember now!  I hope you get some clear skies soon.