2" seeker / wide FOV EP showdown: APM UFF 30mm vs Meade UWA 24mm vs Skywatcher Myriad 20mm

[MetroiD]

I recently had the opportunity to put these three side by side. Considering their TFOV is almost exactly the same, I was slightly surprised by my findings so I thought I'd share with you guys. 
tl;dr: The APM UFF 30mm is bloody amazing.

Meade's 24mm UWA was the very first widefield EP I purchased almost as soon as I'd laid eyes on this holy hand grenade of an eyepiece. And I did learn to love it - much more so in my bottom-heavy 12" flex tube dob than the smaller ones that preceded it - but I was always bothered by its ergonomics (which had admittedly attracted me in the first place). The widefield 24mm was in regular use as my lowest-magnification "seeker" eyepiece - but then earlier this year the EP itch saw me grab an APM UFF 30mm from Germany - which coincidentally was the direction in which the Meade later departed. But not before I'd had the opportunity to test these two side by side and confirm that the much newer design in APM's UFF series trumps Meade's variation on the Nagler.

Field curvature was present as a shift in focus in the outer ~10% of the field in the Meade even when simply looking at star fields. With a clear target in sight, things did seem a tad better, no doubt due to the UWA's rather engaging 'spacewalk' view. However, when the same object was seen through the 30mm UFF, things immediately looked much crisper and yes, even more 'exciting'. I know that the latter is a poor marker for any eyepiece's performance but it's still part and parcel of the whole starry skies experience. Colour transmission in the APM was decidedly more neutral and contrast was on a different scale altogether - apart from the fact that the field was... well, ultra flat - there's a reason they called it that. Regardless whether I was looking at random star fields, larger targets (think M31), clusters, nebulae or the moon, the results remained unchanged. Better design, better optics and definitely better coatings - the APM won hands down. 

Shortly after the 30mm UFF had carved itself a firm place in my EP case, I stumbled upon a 100-degree Skywatcher Myriad 20mm. Buoyed by the fact that my flex-tube telescope had already proven it had a way with heavy eyepieces, I jumped at the opportunity - especially seeing as I'd been casting glances at the rebranded APM XWAs for a while.

By the time I could take my two lowest-magnification eyepieces out for a spin, the Hercules Cluster was high enough to provide a wonderful arena for the battle between the UFF and XWA's ancestor-of-sorts. Considering how it cost almost twice as much as the UFF (both used), I was looking forward to amazing feats from the Myriad. I aimed my f/4.9 reflector at the Hercules cluster and was half-expecting something along the lines of an Obsession Telescopes ad. In went the 600-gram EP - but my jaw remained very much undropped. I had already peered through a 21mm Ethos at that point so I knew what 100 degrees looks and feels like but on this occasion, I was immediately transported to the feeling that my old 24mm Meade used to give me. Very nice indeed - but still a performance that could be upgraded upon. The UFF readily revealed a much more crisp layout within M13, and I felt as though I was even seeing more stars within the globular cluster. By the time my eyes had gotten used to the improving conditions, I was already convinced that the lightweight UFF was the one to keep. I tried a quick glimpse at low-lying M31 - not a good view by a long shot so neither eyepiece seemed to perform particularly well. Clearly though, the UFF showed better transmission. 9 elements in 6 groups for the Myriad vs 9 elements in 5 groups for the UFF - apparently, it does make a difference in terms of transmission so it would be interesting to see actual values on this. 

Curious to find out whether there was any discernible field distortion with either, I then started randomly starhopping and taking in the widefield views. I still wanted to be amazed by the Myriad but kept confirming that, in this telescope, the UFF was simply superior. In the end, the Skywatcher/OVL EP didn't drop my jaw - but it definitely made my head spin quite a bit. That night I'd driven about 40 minutes away from home to enjoy better viewing conditions- but by the time I decided to call it a night, I was so nauseated by all the starhopping that it took me about two hours before I could finally crawl into bed. Lesson learnt the hard way: "floating in space" is not all it's cracked up to be.

A few months later, I had the opportunity to test the Myriad vs the UFF once again, this time in a 14" f/4.3 Newtonian. As I'd expected, the field distortion I'd already sensed in the 20mm Skywatcher was far more discernible. But what sealed the deal for me was the view of M57. In the UFF, despite the very low magnification, the Ring Nebula almost showed some level of detail. The 20mm Myriad should have made for a much clearer view given its 50% increase in magnification vs the 30mm - but I just didn't feel like I was able to see any more detail than with the UFF. After this session, the Myriad found a new home - along with my 12" dob. The featherweight UFF's performance in the rather quick f/4.3 truss tube convinced me that I could get away with using my current EP collection without a Paracorr - so we quickly made friends with the 14" scope, and by the looks of it, my 30mm APM has cemented its place as my go-to widefield EP.

Overview
Conditions: Bortle 4>3 skies
Observer: no issues w/ vision, don't wear glasses
Telescope: 12"/305cm f/4.9 Newtonian; later 14"/350cm f/4.3 Newtonian
Focuser: Omegon Monorail Steel track 
Corrector / Barlow: None
Filter: None

Specs for each eyepiece based on 12" Newtonian parameters: 
Meade UWA 24mm: AFOV 82 / 78.7 arcmin; magnification 63x; exit pupil 4.9mm; eye relief 17mm; calculated field stop 34.3mm
Skywatcher Myriad 20mm: AFOV 100 / 80 arcmin; magnification 75x; exit pupil 4.1mm; eye relief 15mm; calculated field stop 34.9mm
APM UFF 30mm: AFOV 70 / 84 arcmin; magnification 50x; exit pupil 6.9mm; eye relief 22mm; calculated field stop 36.7mm

Meade UWA 24mm: 
+ Cheap(er than the other two)
+ Very engaging views
+ That big cloak really does its job well and helps find / retain the perfect eye relief
? Decloakable - you could slim it down if you're so inclined
- Very bulky and heavy
- Noticeable field curvature when compared to more modern designs
- Can get greasy: Meade have gone slightly overboard with the oil on the cloaking mechanism

Skywatcher Myriad 20mm:
+ Huge field of view
+ Great eye guard - I've always been a fan of twist-up rather than fold-up, especially with such big EPs
- The sheer size of it
- Some field curvature - nothing too dramatic considering the AFOV.
- Pricey and hard to find - long lead times when new, a rare Pokemon on the second-hand market

APM UFF 30mm:
+ Brilliant, sharp and engaging view
+ Light transmission and contrast on par with the best EP's I've ever used
+ Ergonomic: light and compact EP, great fit for truss-tube dobs
+ Quite affordable given its performance

Edited October 17, 2022 by MetroiD

[badhex]

Nice comparison. I have the 24mm UFF and it is a fantastic EP, so your findings with the 30mm don't surprise me at all. 

If you are looking at supplementing your EP collection with any of the others in the range, FLO have recently launched their own StellaLyra branding of the UFF range which are identical to the original APMs. 

[MetroiD]

Thank you for your kind words! The way I look at the 30mm UFF is more or less like a first cousin to my current collection of Morphei. With the longest FL among those clocking in at 17.5mm, I can't really say I need an additional EP between that and the 30mm - however if I were at any point to add one, it would certainly be the 24mm UFF. 

Funnily enough, "uff" in Bulgarian is just a grunt you'd normally utter in annoyance. Thankfully, my stargazing mates still haven't started getting annoyed at the amount of praise I keep throwing at this EP - all thoroughly deserved. All things considered, I can safely say that the extended German family of Morphei + UFFs should provide stellar stellar views (bad pun intended :P) in any Newtonian. And as a sidenote - in a quite literal 'pound for pound' aka 'bang for your buck' matchup, sadly I'd have to say the Myriad would be a non-starter.

[badhex]

The Morpheus range is awesome, and I particularly like the 17.5mm. I also tend to jump often from lowest power (usually 35mm or 40mm) straight to the 17.5mm because the difference in mags is very small, but there are some moments when the 24mm wins out (it's also a slightly better EP than the lowest power ones I own. 

I have only come across Myriad range as a different brand actually, TS-Optics amongst other do versions of them but hadn't realised SW did them too. I quite like the 64-75 deg.-ish AFOV so never really played with EPs much wider than that. 

[Mr Spock]

So far I've only had a look through the 30mm StellaLyra UF in the 60mm Tak. Daytime only, but it was razor sharp. I can't wait to try it in my bigger scopes. I did note a little field curvature, but I believe that to be from the scope given the low power, wide field, view.

[cajen2]

I recently bought the Celestron Ultima Edge 30mm, which is yet another clone of the UFF. I was extremely impressed by its clarity, contrast and ability to show targets sharp right to the edge of the FOV. I also have several higher-mag Morpheii and you're right: it's very reminiscent of a Morph view.

Once again note that the new StellaLyra UF is the same EP (apart from cosmetic differences) but is £40 cheaper than the CUE.

[Don Pensack]

The StellaLyra makes the 9th label of the 30mm available.

But it is quite cost-effective.  Kudos to FLO.

[johnturley]

On 05/10/2022 at 21:07, MetroiD said:

I recently had the opportunity to put these three side by side. Considering their TFOV is almost exactly the same, I was slightly surprised by my findings so I thought I'd share with you guys. 
tl;dr: The APM UFF 30mm is bloody amazing.

Meade's 24mm UWA was the very first widefield EP I purchased almost as soon as I'd laid eyes on this holy hand grenade of an eyepiece. And I did learn to love it - much more so in my bottom-heavy 12" flex tube dob than the smaller ones that preceded it - but I was always bothered by its ergonomics (which had admittedly attracted me in the first place). The widefield 24mm was in regular use as my lowest-magnification "seeker" eyepiece - but then earlier this year the EP itch saw me grab an APM UFF 30mm from Germany - which coincidentally was the direction in which the Meade later departed. But not before I'd had the opportunity to test these two side by side and confirm that the much newer design in APM's UFF series trumps Meade's variation on the Nagler.

Field curvature was present as a shift in focus in the outer ~10% of the field in the Meade even when simply looking at star fields. With a clear target in sight, things did seem a tad better, no doubt due to the UWA's rather engaging 'spacewalk' view. However, when the same object was seen through the 30mm UFF, things immediately looked much crisper and yes, even more 'exciting'. I know that the latter is a poor marker for any eyepiece's performance but it's still part and parcel of the whole starry skies experience. Colour transmission in the APM was decidedly more neutral and contrast was on a different scale altogether - apart from the fact that the field was... well, ultra flat - there's a reason they called it that. Regardless whether I was looking at random star fields, larger targets (think M31), clusters, nebulae or the moon, the results remained unchanged. Better design, better optics and definitely better coatings - the APM won hands down. 

Shortly after the 30mm UFF had carved itself a firm place in my EP case, I stumbled upon a 100-degree Skywatcher Myriad 20mm. Buoyed by the fact that my flex-tube telescope had already proven it had a way with heavy eyepieces, I jumped at the opportunity - especially seeing as I'd been casting glances at the rebranded APM XWAs for a while.

By the time I could take my two lowest-magnification eyepieces out for a spin, the Hercules Cluster was high enough to provide a wonderful arena for the battle between the UFF and XWA's ancestor-of-sorts. Considering how it cost almost twice as much as the UFF (both used), I was looking forward to amazing feats from the Myriad. I aimed my f/4.9 reflector at the Hercules cluster and was half-expecting something along the lines of an Obsession Telescopes ad. In went the 600-gram EP - but my jaw remained very much undropped. I had already peered through a 21mm Ethos at that point so I knew what 100 degrees looks and feels like but on this occasion, I was immediately transported to the feeling that my old 24mm Meade used to give me. Very nice indeed - but still a performance that could be upgraded upon. The UFF readily revealed a much more crisp layout within M13, and I felt as though I was even seeing more stars within the globular cluster. By the time my eyes had gotten used to the improving conditions, I was already convinced that the lightweight UFF was the one to keep. I tried a quick glimpse at low-lying M31 - not a good view by a long shot so neither eyepiece seemed to perform particularly well. Clearly though, the UFF showed better transmission. 9 elements in 6 groups for the Myriad vs 9 elements in 5 groups for the UFF - apparently, it does make a difference in terms of transmission so it would be interesting to see actual values on this. 

Curious to find out whether there was any discernible field distortion with either, I then started randomly starhopping and taking in the widefield views. I still wanted to be amazed by the Myriad but kept confirming that, in this telescope, the UFF was simply superior. In the end, the Skywatcher/OVL EP didn't drop my jaw - but it definitely made my head spin quite a bit. That night I'd driven about 40 minutes away from home to enjoy better viewing conditions- but by the time I decided to call it a night, I was so nauseated by all the starhopping that it took me about two hours before I could finally crawl into bed. Lesson learnt the hard way: "floating in space" is not all it's cracked up to be.

A few months later, I had the opportunity to test the Myriad vs the UFF once again, this time in a 14" f/4.3 Newtonian. As I'd expected, the field distortion I'd already sensed in the 20mm Skywatcher was far more discernible. But what sealed the deal for me was the view of M57. In the UFF, despite the very low magnification, the Ring Nebula almost showed some level of detail. The 20mm Myriad should have made for a much clearer view given its 50% increase in magnification vs the 30mm - but I just didn't feel like I was able to see any more detail than with the UFF. After this session, the Myriad found a new home - along with my 12" dob. The featherweight UFF's performance in the rather quick f/4.3 truss tube convinced me that I could get away with using my current EP collection without a Paracorr - so we quickly made friends with the 14" scope, and by the looks of it, my 30mm APM has cemented its place as my go-to widefield EP.

Overview
Conditions: Bortle 4>3 skies
Observer: no issues w/ vision, don't wear glasses
Telescope: 12"/305cm f/4.9 Newtonian; later 14"/350cm f/4.3 Newtonian
Focuser: Omegon Monorail Steel track 
Corrector / Barlow: None
Filter: None

Specs for each eyepiece based on 12" Newtonian parameters: 
Meade UWA 24mm: AFOV 82 / 78.7 arcmin; magnification 63x; exit pupil 4.9mm; eye relief 17mm; calculated field stop 34.3mm
Skywatcher Myriad 20mm: AFOV 100 / 80 arcmin; magnification 75x; exit pupil 4.1mm; eye relief 15mm; calculated field stop 34.9mm
APM UFF 30mm: AFOV 70 / 84 arcmin; magnification 50x; exit pupil 6.9mm; eye relief 22mm; calculated field stop 36.7mm

Meade UWA 24mm: 
+ Cheap(er than the other two)
+ Very engaging views
+ That big cloak really does its job well and helps find / retain the perfect eye relief
? Decloakable - you could slim it down if you're so inclined
- Very bulky and heavy
- Noticeable field curvature when compared to more modern designs
- Can get greasy: Meade have gone slightly overboard with the oil on the cloaking mechanism

Skywatcher Myriad 20mm:
+ Huge field of view
+ Great eye guard - I've always been a fan of twist-up rather than fold-up, especially with such big EPs
- The sheer size of it
- Some field curvature - nothing too dramatic considering the AFOV.
- Pricey and hard to find - long lead times when new, a rare Pokemon on the second-hand market

APM UFF 30mm:
+ Brilliant, sharp and engaging view
+ Light transmission and contrast on par with the best EP's I've ever used
+ Ergonomic: light and compact EP, great fit for truss-tube dobs
+ Quite affordable given its performance

Nice report, I'm seriously think of getting the 30mm StellaLyra variant (from FLO), and selling both my ES 24 mm 82 (which I understand is similar if not the same as the Meade 24 mm UWA), and Baader Aspheric 36 mm). The only thing putting me off is that I had for a short period a 50 mm StellaLyra eyepiece, which claimed an APFOV of 60 degrees, but in reality it was around only 45 degrees.

John 

Edited December 31, 2022 by johnturley

[Don Pensack]

9 minutes ago, johnturley said:

Nice report, I'm seriously think of getting the 30mm StellaLyra variant (from FLO), and selling both my ES 24 mm 82 (which I understand is similar if not the same as the Meade 24 mm UWA), and Baader Aspheric 36 mm). The only thing putting me off is that I had for a short period a 50 mm StellaLyra eyepiece, which claimed an APFOV of 60 degrees, but in reality it was around only 45 degrees.

John 

The 30mm is in a different league.  It's truly a high-end eyepiece.  You won't be disappointed.  It's a real 70°.  And sharp down to f/4.

KUO really has a superb eyepiece here, with the 30mm--contrast and sharpness are excellent.

[johnturley]

Ordered a StellaLyra 30mm UFF from FLO last week, and it arrived by express courier the next day, and since than have been able to try it out a couple times through my 14 in Newtonian, and overall quite impressed. As mentioned in another thread, I have been looking for some time for a low power wide field eyepiece that is both not excessively bulky and heavy, and will be sharp to the edges of the field of view in an f5 instrument, and the StellaLyra 30 mm UFF comes close to achieving both these aims. At 550g (not including lens caps, 570g with) it is no lightweight, but this is about 2/3rds of that of my ES 24 mm 82 degree eyepiece or 35mm Panoptic, and about half that of a 31mm Nagler, or a 30 mm ES 82 degree.

Although the star images at the edge of the field of view through my f5 Newtonian were by no means perfect, they were noticeably superior to those in my ES 24 mm 82 degree eyepiece, and vastly superior to my 36 mm Baader Hyperion Aspheric. Although in the case of the former I was comparing an APFOV about 15% smaller, one thing I liked about the StellaLyra was that it had a sharply defined edge compared to the rather mushy edge of the ES 82 degree, and the whole of the field of view was immediately visible, as opposed to having to move the eye around in the case of the latter. 

If anything the claimed 70 degree APFOV of the StellaLyra was a bit on the modest side, holding the two eyepieces side by side, the APFOV was noticeably larger than that of my 24mm 68 degree Panoptic, similar to that of my 36mm 72 degree Hyperion Aspheric, and very close to that of my 17.5 mm 76 degree Morpheus. Before purchasing I was a bit worried that the actual APFOV might be significantly smaller that that claimed, as was the case with a StellaLyra 50mm Superview eyepiece that I once owned, which originally claimed to have an APFOV of 60 degrees, but turned out to be only around 45 degrees. With hindsight, I don't think that it is actually possible to produce a 50mm eyepiece with a 60 degree (or greater) APFOV in a 2in barrel.

Furthermore at £179 (from FLO) the 30 mm StellaLyra UFF, although not cheap and having a smaller APFOV, is quite modestly priced being just over half that of a 30 mm ES 82 degree, or 1/4 that of a 31 mm Nagler. 

John 

Edited January 21, 2023 by johnturley

[Louis D]

You don't say which coma corrector you were using with your f/5 Newtonian.  I've found my 30mm APM UFF to be sharp to the edge with a GSO CC in my f/6 Dob.

I've measured its AFOV to be 73 degrees.  It's eAFOV (to plug into TFOV calculators) is indeed 70 degrees due to slight distortion.

[johnturley]

1 hour ago, Louis D said:

You don't say which coma corrector you were using with your f/5 Newtonian.  I've found my 30mm APM UFF to be sharp to the edge with a GSO CC in my f/6 Dob.

I've measured its AFOV to be 73 degrees.  It's eAFOV (to plug into TFOV calculators) is indeed 70 degrees due to slight distortion.

I don't usually use a coma corrector with my f5 Newtonian, although I do have an Explore Scientific HR Coma Corrector, no doubt the results would be better if I used it, as I tried once with my Baader 36 mm Hyperion Aspheric, and it gave improved results. I don't usually use the coma corrector as its fiddly to use, and the weight of it causes balance issues with my fork mounted Newtonian. The whole point of getting the StellaLyra 30 mm UFF, was to get a well corrected eyepiece which doesn't require a coma corrector, I'm really surprised that you find that there is significant coma with your 30mm APM UFF at f6. 

Interesting that you find the APFOV to slightly greater than the stated 70 degrees, which is unusual, with most eyepieces the APFOV tends to be less than what is claimed.

John 

Edited January 21, 2023 by johnturley

[Mr Spock]

I've recently been using the SL 30mm UF in my 12" f5 Dob. I can report that the last 2-3° needs refocusing to get it sharp, but, once focused there's no trace of coma. 

I was testing it last night on a few wide doubles and when refocused the stars were perfectly formed and very sharp.

[johnturley]

2 hours ago, Mr Spock said:

I've recently been using the SL 30mm UF in my 12" f5 Dob. I can report that the last 2-3° needs refocusing to get it sharp, but, once focused there's no trace of coma. 

I was testing it last night on a few wide doubles and when refocused the stars were perfectly formed and very sharp.

Agree, I find that with the StellaLyra 30mm UFF in my f5 Newtonian, stars at the edge of the field are not in as sharp focus as those in the centre, not that they suffer from coma, but can be re-focused.  With my Baader 36mm Hyperion Aspheric on the other hand, I get seagull shaped images at the edge, which cannot be brought into sharp focus, and which benefit from the coma corrector. 

John 

Edited January 21, 2023 by johnturley

[Mr Spock]

I think it's a case of wide and fast = issues of some kind. Some worse than others. I'll take the fact I don't need the extra expense of a coma corrector to get round stars.

[SuburbanMak]

This is a great shoot-out, thank you. I haven’t had the chance to look through the other eyepieces mentioned but have recently acquired the Stellalyra 30mm UFF, in a very short space of time it has revolutionised the performance of my 2” converted ST80 delivering the kind of views I’d hoped for on upgrading the focuser.  Can’t wait to get it in my f5 10” Dob! 

[Louis D]

1 hour ago, johnturley said:

I don't usually use a coma corrector with my f5 Newtonian, although I do have an Explore Scientific HR Coma Corrector, no doubt the results would be better if I used it, as I tried once with my Baader 36 mm Hyperion Aspheric, and it gave improved results.

 

1 hour ago, johnturley said:

Agree, I find that with the StellaLyra 30mm UFF in my f5 Newtonian, stars at the edge of the field are not in as sharp focus as those in the centre, not that they suffer from coma, but can be re-focused.

Give the ES HR CC a try with the 30mm UFF sometime, and see if both issues are minimized.  Most CCs not only correct coma, they also help to flatten the field.

If you can live with both issues, and the imbalance issues with the CC outweighs the sharpening effects, then definitely continue using the UFF straight into the focuser.

[Louis D]

I just got in from using my 90mm TS-Optics FPL-53 APO (f/6.7) with TSFLAT2 flattener on the Trapezium region, and I could only detect the very slightest amount of astigmatism and field curvature in the last 15% of the 30mm APM UFF's AFOV.  The 30mm ES-82 had vastly more astigmatism, and wasn't nearly as sharp on axis.  I had difficulty splitting the Trapezium anywhere in the field with the ES-82, but could split it everywhere except in that last 15% with the UFF.

My only two eyepieces that were absolutely sharp edge to edge without refocusing were the 12mm and 17mm ES-92s.  The 12.5mm APM Hi-FW was close behind losing just a bit of sharpness in the last 5% of the field.  The 14mm Morpheus had a bit more astigmatism and field curvature nearing the edge.

The 22mm NT4 was had noticeable astigmatism and some field curvature.  The 26mm Meade MWA was noticeably sharper on axis and held onto more of that sharpness nearing the edge without refocusing.

[Don Pensack]

Last night the seeing was too poor to use high powers, so I went back and forth with a 30mm UFF, 22mm T4 Nagler, and 17.5mm and 14mm Morpheus.

I have a 12.5" scope with Paracorr II, operating at f/5.75 with coma correction.

I watched stars leave the field of view on all 3.

In the 30UFF, the stars stayed tiny points right out of the field.  The stars at the field stop were identical to the center.

In the 22mm Nagler, some astigmatism became noticeable a few degrees in from the edge.

The 17.5mm Morpheus was the weakest of the group, with very minor astigmatism in the star images from the 80% point to the edge.

The 14mm Morpheus was seeing limited because of the magnification produced, but during some moments early in the evening I watched a star cluster leave the field still in tight focus with tiny pinpoint stars.

But, I'll repeat what I've said before: the 14mm Morpheus in a Paracorr yields near-perfect stars across the entire field.  I see no astigmatism or field curvature or chromatic aberration.

I do in the 12.5mm, but not the 14mm.

I trust that others do, but I just don't see it in the 14mm.  Is it the Paracorr that corrects the eyepiece to that level?  Or the f/ratio?

I keep going back to this eyepiece because it is so sharp.

Edited January 22, 2023 by Don Pensack

[PeterC65]

I waited for several months for the return of the Aero ED 35mm but when FLO put the Baader Hyperion's on discount before Christmas I bought the Aspheric 36mm instead. It does the job of widefield but clearly suffers from seagull shaped stars in the outer 30% which I find distracting. In part I went for the Aspheric because it can also be used in 1.25" mode as a large exit pupil eyepiece, replacing the Celestron 40mm Omni which I find difficult to use because of the long eye relief (31mm).

The StellaLyra UFF 30mm is tempting but just a bit too close to my existing ES 68° 24mm which I love. I wonder whether @FLO will also stock the 35mm variant in the future?

TS-Optics seem to offer a clone of the Aero ED 35mm but I would prefer to buy in the UK and I'm not completely sure this clone is the same as the well regarded Aero ED 35mm.

 

[Louis D]

3 hours ago, PeterC65 said:

The StellaLyra UFF 30mm is tempting but just a bit too close to my existing ES 68° 24mm which I love. I wonder whether @FLO will also stock the 35mm variant in the future?

35mm variant of which?  The UFF series stops at 30mm and the ES-68 series has 34mm and 40mm members.

3 hours ago, PeterC65 said:

TS-Optics seem to offer a clone of the Aero ED 35mm but I would prefer to buy in the UK and I'm not completely sure this clone is the same as the well regarded Aero ED 35mm.

I have both the 35mm Aero ED and 40mm Lacerta ED versions of these eyepieces.  The 35mm has a wider AFOV, slightly smaller TFOV, and poorer outer field correction than the 40mm.  In fact, last night, I went back and forth between my 40mm ED and 40mm Pentax XW-R, and I think the ED had less field curvature and basically the same level of field correction.  The Pentax does have a larger AFOV due to greater distortion, but basically the same TFOV.  I thought about bringing out the 35mm ED last night, but the tighter eye relief and poorer correction put me off that idea.  I had lots of other comparisons of newer equipment to make that had been queued up for a while, so my time was somewhat limited for revisiting the past.

Basically, I'd say skip the 35mm ED and get the 40mm ED.  The difference in exit pupil and sky brightness is minimal.  I'm pretty sure you've seen my write-up of all of them, but it bears worth repeating for those who haven't:

 

[Louis D]

8 hours ago, Don Pensack said:

The 14mm Morpheus was seeing limited because of the magnification produced, but during some moments early in the evening I watched a star cluster leave the field still in tight focus with tiny pinpoint stars.

 

8 hours ago, Don Pensack said:

I trust that others do, but I just don't see it in the 14mm.  Is it the Paracorr that corrects the eyepiece to that level?  Or the f/ratio?

That is so weird that you consistently get these results with your copy, and I get my results with my copy.  It doesn't matter which scope I use it in or how much edge refocusing I do, the Trapezium clearly loses its distinctive shape nearing the edge in my 14mm Morpheus while the 17mm ES-92 at an even lower power and wider AFOV continues to show it perfectly to the edge without any focus futzing.  I even tipped my head to look straight at the edge to make sure my eyeglasses weren't causing the issue by inducing chromatic aberrations by looking through them off axis, but the view remained the same.

[PeterC65]

38 minutes ago, Louis D said:

35mm variant of which?  The UFF series stops at 30mm and the ES-68 series has 34mm and 40mm members.

I'm assuming that the OEM eyepiece range from which the StellaLyra UFF is a branding includes the 35mm since other brandings (the TS-Optics one that I mentioned) seem to include longer focal lengths.

42 minutes ago, Louis D said:

I have both the 35mm Aero ED and 40mm Lacerta ED versions of these eyepieces.  The 35mm has a wider AFOV, slightly smaller TFOV, and poorer outer field correction than the 40mm.  In fact, last night, I went back and forth between my 40mm ED and 40mm Pentax XW-R, and I think the ED had less field curvature and basically the same level of field correction.  The Pentax does have a larger AFOV due to greater distortion, but basically the same TFOV.  I thought about bringing out the 35mm ED last night, but the tighter eye relief and poorer correction put me off that idea.  I had lots of other comparisons of newer equipment to make that had been queued up for a while, so my time was somewhat limited for revisiting the past.

Unfortunately the Lacerta 40mm seems to be in very short supply again, with little data available about it.

[Franklin]

10 hours ago, Louis D said:

I just got in from using my 90mm TS-Optics FPL-53 APO (f/6.7) with TSFLAT2 flattener

Can the TSFLAT2 be used for visual then? I was under the impression that it was intended for photographic use. I've got one somewhere, must give it a try in the Vixen FL55SS and see if it can flatten out the field curvature a bit.

[Don Pensack]

1 hour ago, Franklin said:

Can the TSFLAT2 be used for visual then? I was under the impression that it was intended for photographic use. I've got one somewhere, must give it a try in the Vixen FL55SS and see if it can flatten out the field curvature a bit.

A number of people use the field flattener for visual.  It works in scopes of f/4-f/9.

You will need spacers to get to its working distance.  Extension tubes will work if your scope has sufficient in travel left in the focuser.  Otherwise, barrel extenders if attached directly to an eyepiece.