TV Delos 12mm vs 13mm Nagler T6

[jetstream]

On 18/03/2023 at 16:59, Pixies said:

Anyone here have experience with the 12mm Delos and 13mm Nagler (T6)?

I havnt had either but own a few Delos. They are very high transmission eyepieces with great contrast. Greater than my 16T5 Nagler and sharper. The 13mm Nagler is considered a very desirable eyepiece including by me and I will own one soon, for my refractors. Even if it doesnt "beat" a Delos it will still be in my refractor EP case, whereas the Delos are in my dob cases.

We are lucky to be able to make these decisions IMHO, Gerry

[jetstream]

On 03/04/2023 at 09:56, nicholasastro said:

I suspect the 12.5mm Docter would take things a tiny step further forward,

The only EP's that go deeper than this EP are orthos IMHO.

[nicholasastro]

12 hours ago, jetstream said:

The only EP's that go deeper than this EP are orthos IMHO.

Yes, I can fully appreciate that. For a while I used to use the longer focal length (16, 14 and 12mm) TMB Supermonocentrics for teasing out every last detail within DSOs, despite the very narrow 30 degree apparent field of view. I did this whilst placing my dob on an equatorial platform to assist with tracking objects.

Anticipating possible replies to this response in the thread, I'm fully aware of off-axis issues related to field curvature, which never really bothered me too much with these eyepieces, particularly as I like to observe and focus on what can be seen in the centre of the field of view 🤣😁

[jetstream]

6 minutes ago, nicholasastro said:

as I like to observe and focus on what can be seen in the centre of the field of view

Me too! 100%.

I wish I had a set of real TMBs...

Normally I observe with comfortable eyepieces like my zooms or Delos and then for a bit during a session get the specialists out.

[Pixies]

OK - now I can compare.

Just have to wait until August for dark skies again....

[Highburymark]

3 hours ago, Pixies said:

OK - now I can compare.

Just have to wait until August for dark skies again....

We’ll need a report sooner than that I’m afraid 😄 An interesting contest. Personally I love the Delos and Delites. I do think they have the edge over most other medium widefields in sharpness. But I thought the 11mm T6 Nagler came very close - never tried a 13mm. 

[Louis D]

The 12mm Delos should be fantastic if my 10mm Delos is any indication.

A more appropriate comparison for the 12mm Delos would be against other long eye relief eyepieces in this range: 12.5mm Morpheus, 12.5mm Docter/Noblex, 12.5mm APM Hi-FW, 12mm Nagler T4 and 12mm ES-92 (did I miss any?).  I have the last three, and really like the APM for 1.25" use in smaller scopes and the ES for 2" use in larger scopes.  I can't afford the Docter/Noblex and consider the Morpheus too redundant with the APM and my 14mm Morpheus.  I should pass along the NT4 sometime because I never use it anymore.

[John]

I used the 14mm Delos and the 13mm Ethos tonight. Both really nice but I find the Ethos view the most engaging. I don't wear glasses when observing though.

 

[Louis D]

34 minutes ago, John said:

I used the 14mm Delos and the 13mm Ethos tonight. Both really nice but I find the Ethos view the most engaging. I don't wear glasses when observing though.

I know you briefly had the 12mm ES-92.  How did the engagement differ between it and the 13mm Ethos?  I vaguely recall you had difficulty holding the exit pupil of the ES-92.

Wearing glasses, the ES-92s feel to me like the Delos/XW/Morpheus/Hi-FW taken up a notch in engagement without losing any of the ease of taking in the entire view at once.  There's no comparison to the 12mm/17mm NT4s which are both very difficult to hold the entire view while wearing eyeglasses.

[Highburymark]

I’ve been toying with idea of trading in my one very wide binoviewing pair (Morpheus 12.5mm) for a pair of Delos 14mm. Mostly used for solar Ha, the Morpheus pair are incredible for showing a full solar disc at around 125x, but my Delite pairs are a noticeable step up in sharpness. On the Moon, the difference between them is closer. The Morpheus are excellent all-rounders though, and terrific value at the moment in the U.K. - £180 or so.

[John]

51 minutes ago, Louis D said:

I know you briefly had the 12mm ES-92.  How did the engagement differ between it and the 13mm Ethos?  I vaguely recall you had difficulty holding the exit pupil of the ES-92.

Wearing glasses, the ES-92s feel to me like the Delos/XW/Morpheus/Hi-FW taken up a notch in engagement without losing any of the ease of taking in the entire view at once.  There's no comparison to the 12mm/17mm NT4s which are both very difficult to hold the entire view while wearing eyeglasses.

I found the 12mm ES-92 optically extremely good but ergonomically very difficult. The eye relief for me, as a non glasses wearer, meant that I needed to "hover" my eye well off the top of the eyecup which is not a relaxed position and let stray light onto the eye lens of the eyepiece, which reduced contrast. I moved the eyepiece on to a new owner quite quickly. I found the 17mm ES-92 a bit easier in this respect so held onto it for longer. The only NT4 that I have owned is the 22mm which is reputedly the easiest Nagler for glasses wearers to get on with.

Having read many accounts of experiences of eyepieces from folks who wear glasses when observing I have come to the conclusion that the experiences of glasses wearers vs non glasses wearers is very often going to be different where eyepieces are concerned.  

 

[Louis D]

20 minutes ago, John said:

The only NT4 that I have owned is the 22mm which is reputedly the easiest Nagler for glasses wearers to get on with.

Correct.  It is usable thanks to it's SAEP being the mildest of the line.

21 minutes ago, John said:

Having read many accounts of experiences of eyepieces from folks who wear glasses when observing I have come to the conclusion that the experiences of glasses wearers vs non glasses wearers is very often going to be different where eyepieces are concerned.  

No doubt.  Eyepieces that appeal to non-eyeglass wearers don't generally appeal to eyeglass wearers and vice-versa.  There are those with long eye relief and adjustable eye guards which seem to appeal to both.

As an example of the first case, having looked through a 21mm Ethos at a star party while wearing eyeglasses, I was very much "Meh" about it.  If I could see 70 degrees AFOV, I'd be surprised.  I took my glasses off, put my eye socket against the eye cup, and was greeted with loads of astigmatism (at least with bright stars) across the 100 degree field.  All of the faint stars disappeared thanks to my eye astigmatism.  I was completely underwhelmed by it.  I'm sure if I didn't have 2+ diopters of astigmatism, I'd have been more impressed by it.

Perhaps if ES added an adjustable eye guard to the ES-92 line, it would have more general appeal.

[Don Pensack]

11 hours ago, Louis D said:

Perhaps if ES added an adjustable eye guard to the ES-92 line, it would have more general appeal.

And if they removed a lot of the weight.

12mm ES 92--1017g

11mm TeleVue Apollo 11 85°--612g, or 405g lighter, or about 0.9 lbs!

Yes, 92° is wider than 85°, but not by that much.

Both are usable with glasses.

 

[Louis D]

10 hours ago, Don Pensack said:

And if they removed a lot of the weight.

12mm ES 92--1017g

11mm TeleVue Apollo 11 85°--612g, or 405g lighter, or about 0.9 lbs!

Yes, 92° is wider than 85°, but not by that much.

Both are usable with glasses.

 

And the TV Apollo 11mm would be a lot more popular if they had cut about $800 off the cost.  I'm not sure how well it would have sold without the caché of being a limited edition eyepiece.

[Don Pensack]

13 hours ago, Louis D said:

And the TV Apollo 11mm would be a lot more popular if they had cut about $800 off the cost.  I'm not sure how well it would have sold without the caché of being a limited edition eyepiece.

Without the fancy box or medallion, and fast air freight and speeded-up production costs, it could have been in the Ethos price range.

A line of them might be at the Ethos price points, and I, for one, would buy every focal length they make up to maybe 16-17mm.  My eyepieces longer than that right now are just fine.

[Louis D]

I'd probably like a 22mm to 25mm Apollo to replace the 22mm NT4 which needs better eye relief and less SAEP.  I'd pay up to $600 for one, possibly more, if absolutely perfectly corrected, flat of field, 18mm of usable eye relief, and no SAEP at all.

I'm good with the ES-12 and ES-17, so no desires for Apollos there.  I can always Barlow these two to easily get to 8.5mm and 6mm focal lengths.  I've done this, but I have never felt like I wanted to use that amount of FOV at those focal lengths.

[Don Pensack]

3 hours ago, Louis D said:

I'd probably like a 22mm to 25mm Apollo to replace the 22mm NT4 which needs better eye relief and less SAEP.  I'd pay up to $600 for one, possibly more, if absolutely perfectly corrected, flat of field, 18mm of usable eye relief, and no SAEP at all.

I'm good with the ES-12 and ES-17, so no desires for Apollos there.  I can always Barlow these two to easily get to 8.5mm and 6mm focal lengths.  I've done this, but I have never felt like I wanted to use that amount of FOV at those focal lengths.

Interesting.  I prefer wider and wider fields of view the higher the magnification.  I have non-tracking scopes.

A 22mm Apollo, if scaled, would be the weight of an ES 92.

The 23mm Pentax 85° shows how hard it is to push a design that far without optical consequences.

The 25mm EX 100° also shows the same thing.

One thing I would count on Tele Vue not to do is to make serious compromises in design.

But will we see an entire line?

First, Al is retired and Paul is gone.

Second, their factory is completely maxed out and they would have to sacrifice something else for the factory to fit in another eyepiece, and they are already in the 4 to 6 month delay status on some of their eyepieces and other items.

It would also represent a huge investment--maybe $125k per focal length.

[Louis D]

At higher powers, I'm generally looking at smaller objects, and 70 to 78 degree AFOVs seem plenty wide enough for my non-tracking observing of such objects.

[John]

28 minutes ago, Louis D said:

At higher powers, I'm generally looking at smaller objects, and 70 to 78 degree AFOVs seem plenty wide enough for my non-tracking observing of such objects.

For me, I like as wide as possible. The 110 degree AFoV Ethos SX 4.7 was (again) invaluable as I observed (un-tracked) the quasar 3C 273 tonight. For glasses wearers when observing, <15mm of eye relief is "no go" I appreciate 🙂

Edited May 16, 2023 by John

[Piero]

To me, it really depends on the required magnification. 

I am fine with 70-80 deg AFOV with my refractor (4" f/7.4) at high power (~200-250x), but when I use my 16" f4 + PC2 at > 300x, 70 deg AFOV starts being a pain to me and things get just worse when the target is invisible in the finder. That's one of the reasons why I decided to move from 8-6-4.5mm Delos to 9-7-4.77mm APM XWA. For completeness, the other reasons are: a) I prefer 9, 7mm f.l. to 8, 6mm with that telescope, b) the APM XWA feel a touch lighter but offer more view, c) the AFOV of Docter and N22T4 feels closer to APM XWA than Deloi.