Baader Hyperion 24mm vs. StellaLyra UFF/Altair Ultraflat/APM UFF etc. 24mm?

[Oscar23]

Hi all, new to the forum but not to reading it I've spent the last few evenings obsessively looking for info on these two eyepieces for my dad, he's an older fellow and always busy like a bee so I decided to do the research for him as we share telescopes. He's got a NexStar 4SE and we want a good wide-AFOV EP to max out the true field of view, without breaking the bank. It can only use 1.25" EPs so no 2" tomfoolery allowed. He also wears glasses, so that's a consideration. I've narrowed it down to the Hyperion 24 and the UFF 24, designed for APM but going by a splattering of different first names these days. Reviews indicate both are pretty good in their own right, and as I understand it actually yield a slightly-larger-than-normally-possible true field for 1.25" EPs thanks to some kind of optical wizardry. Something to do with the "virtual" field stop being in the main body of the EP instead of the nosepiece. Anyways, I haven't seen any direct comparisons drawn between the two on the same scope, closest I got was a thread on CloudyNights where someone asked this exact question but didn't get an answer and didn't follow up.

So, for anyone that has, or had, both: how do they compare, and what scope(s) did you try them with? Differences in optical quality, ease of viewing, etc? I think edge clarity would be the most important performance factor here. The Hyperion seems like it should be a tad worse, just looking at it externally, with the smaller eye lens and slightly wider AFOV. But I'm very open to being wrong, hence why I'm asking. I know the UFF 30 is very good, but of course can't put that in a 1.25" focuser...

Other names I'm aware of the UFF 24 being sold under, for reference: Celestron Ultima Edge, Meade Series 5000 UHD, Sky Rover UF, Technosky UltraFlatField (not sure if the CamelCase was intentional or not - it seems Technosky doesn't sell them anymore, so I can't check). Artesky and Svbony also sell UFFs, but not in 24mm.

All relevant information greatly appreciated!

Edited May 21 by Oscar23

[Ags]

Never used the UFF, but the Hyperion 24 was brilliant in my 4SE. Later I bought a 150 PDS, a much 'faster' scope obviously, and the Hyperion was abominable in that. I sold it in favor of a Explore Scientific 24/68, which performed perfectly in all my scopes.

[Nik271]

Welcome to SGL!

Same as Ags here: I have the Hyperion and it's great in my Maks I use it as the default wide field EP. It is very comforable to use with plenty of eye relief. At F12 the view is sharp to the edge. In my refractor at F7 it is so-so - starts to gets soft about 70% out from the centre, not terrible but for example I also have the 17.5mm Morpheus and that is way better at F7 than the Hyperion. In your Nextstar the Hyperion will work very well.  I have not used the UFF my guess is that it is more future proof, i.e. it will work in faster scopes if you decide to change in the future.

 

 

Edited May 21 by Nik271

[Oscar23]

Thanks for the replies, guys; I just finished reading through bosun21's thread here (which I slightly embarrassingly missed on the way in) and caught Don Pensack's comment comparing the two, so I think you might be right Nik. I do still wonder how they'd compare "head to head" on a slow scope equally suitable for both. But, given they're about the same price (at least with the cheaper iterations of the UFF), opting for the more broadly compatible UFF seems to make sense.

I briefly considered the ES 68 and Panoptic 24mm, but, even if budget could be stretched, neither could be used with glasses as I understand it, which I forgot to mention in the OP and will edit it in now - pops does wear glasses. I heard the Panoptic is kind of futzy to get a good view through as well, whereas the UFFs seem to be more forgiving, at least the ones with big eye lenses.

Come to think of it, he likes my 40mm plossl a lot, and likes barlows in general, which I realise now eye relief probably plays a part in...

Edited May 21 by Oscar23

[Oscar23]

To be honest, just the fact that I can get a UFF without an undercut/taper has me inclined towards it - my 40 plossl is an Omni and it has an undercut, which I've learned is a most effective innovation that provides the hapless stargazer with an infinite supply of time wasted and curses uttered whilst fumbling around in the dark with set screws and knocking his telescope off-target!

Maybe a very silly reason, maybe Baader undercuts are just better somehow, but I can't help but be wary.

Edited May 21 by Oscar23

[Louis D]

I've used plenty of eyepieces that are fuzzy due to astigmatism or chromatism from 50% or 70% out to the edge in slower (sub-f/6) scopes.  While they all somewhat sharpen up in slower f/10 to f/12 scopes like SCTs and Synta Maks, the better eyepieces which are nearly sharp to the edge in faster scopes completely sharpen up to the edge in slower scopes appearing like an ultra-premium eyepiece in a slower scope.  If you go to f/18 or f/24 with Barlows, GPCs, OCSs, etc., then the gap narrows considerably as with my Svbony 20mm 68 degree UWAs that I use in my BV.

I would go for the 24mm UFF over the 24mm Hyperion any day for about the same money.  I have the original APM version, and while not perfect at f/6. it is still quite good center to edge.  These images were taken through an f/6 72ED refractor:

At f/12 in a 127mm Synta Mak, it's very good:

As you can see, though, going with a 2-inch visual back and diagonal really opens up the true field of view (TFOV) with some vignetting toward the edge.

[Oscar23]

Hi Louis - I've seen your charts before, actually! One of the things that put me on to the UFF 24. Much appreciated. Too bad you don't have a pic of the Hyperion 24 in your testing setup to compare side-by-side, I'll have to take your word that it's the better of the two. As an aside, I recently learned that the Altair version of the UFF 24 is almost 100g heavier than the others, which is good to know... I was leaning towards the Altair for the safety kerfs, but really, they're not necessary, just neat.

[DAT]

I wear glasses and have not had a problem with with the es 24mm 68. The eye relief is about 18mm I think and just about enough. I like this ep but cannot comment on the others

[Don Pensack]

Get the 24mm UFF:

sharper in outer 50% of field

a bit more eye relief

more elements- better corrected

more true field

lower distortion

better contrast

For glasses, 24mm, and widest field, it is the one.  APM's version has a smooth lower barrel.  I'm not sure any of the others does--maybe Svbony.

[Mr Spock]

No undercut and down to £125 in the sale!
https://www.firstlightoptics.com/stellalyra-eyepieces/stellalyra-24mm-ultra-flat-field-125-eyepiece.html

[Oscar23]

Don, that's exactly the information I was looking for, thank you so much! Michael, I knew about that sale, but I do appreciate bringing it up. So, StellaLyra UFF it will be. Not sure exactly when we'll grab it but I'd guess it'll be before the sale is up.

I'm thinking we might throw in a 32mm plossl as well, specifically I'm eyeing the Badder classic plossl. FLO has it so we could throw it in with the UFF to save on shipping. Then we'd have a max-field range of 24-32-40mm, all with about the same true field, but at different brightness and power. What do you guys think?

[bosun21]

11 hours ago, Oscar23 said:

Hi Louis - I've seen your charts before, actually! One of the things that put me on to the UFF 24. Much appreciated. Too bad you don't have a pic of the Hyperion 24 in your testing setup to compare side-by-side, I'll have to take your word that it's the better of the two. As an aside, I recently learned that the Altair version of the UFF 24 is almost 100g heavier than the others, which is good to know... I was leaning towards the Altair for the safety kerfs, but really, they're not necessary, just neat.

I just bought the Altair 24mm UFF and for £30 cheaper than the SL I will happily accept the extra 100g. I don't think my AZ-EQ6 will complain much.

[Oscar23]

I could see it making a difference on the 4SE, depending. It's a small scope and the electronic mount kinda struggles as it is for slow-motion adjustments. Altair also doesn't sell the Baader plossl... though they do sell Celestrons. I suppose it might be splitting hairs, but still.

And, I'll admit it's vain, but the green on the Altair would clash pretty badly with the orange scope!

[Don Pensack]

The Baader 32mm Plossl is only 45° and does not have a "full" 1.25" field.  It does have good optics, though, and a glasses friendly eye relief.

Other 32mm Plossls will have a wider true field.  Look for a 27mm field stop or larger.

Edited May 22 by Don Pensack

[bosun21]

3 hours ago, Don Pensack said:

The Baader 32mm Plossl is only 45° and does not have a "full" 1.25" field.  It does have good optics, though, and a glasses friendly eye relief.

Other 32mm Plossls will have a wider true field.  Look for a 27mm field stop or larger.

What is a good 32mm plossl or the like Don? I just want it for a 180 Mak for outreach.

[Oscar23]

Status update: I have it  

However, the box it came in had a sticker on it saying "MAY CONTAIN CLOUDS", and they weren't kidding! It was sunny that morning, but by the time I got to unpacking it, clouds had rolled in, and have vehemently refused to go away, despite my best efforts at dissuading them. Maybe now that I post on the forum about it they'll decide to make a liar out of me? Does anyone know if reverse psychology works on clouds?

I almost forgot my initial impressions. Very spartan packaging, but of course as well-protected as you'd expect an eyepiece to be with generous amounts of bubble wrap, and an equally generous helping of scrunched-up paper in the shipping parcel. The only way the box could be more spartan is if was brown instead of black, just a white label with a barcode, part ID, and "QC PASSED" sticker on top, plus another big white label on the front-side with "UF24mm" written on it in a large font. I do appreciate the simplicity in this case... less waste. As for the eyepice itself, the Smyth lens might be the most transparent physical thing I've ever seen - at first invisible to me even though I knew it was there and was looking for it! Overall fit and finish is perfect, nothing to complain about there. I like what I see on the outside. Just need the clouds to part so I can see how it looks on the inside!

Edited June 4 by Oscar23

[John]

On 22/05/2024 at 11:05, bosun21 said:

What is a good 32mm plossl or the like Don? I just want it for a 180 Mak for outreach.

FWIW I use a Vixen NPL 30mm for that use. I got it for peanuts pre-owned but it works well in all my scopes, even at F/6.5. 

I compared the Vixen NPL 30 with a Baader 32 a while (over 10 years now 😬) back. Both were pretty decent but I preferred the Vixen:

Baader Classic 32mm Plossl meets Vixen 30mm NPL Plossl - Member Equipment Reviews - Stargazers Lounge

That was way before FLO introduced the UFF's and others to their range of course.

 

Edited June 4 by John

[Mr Spock]

I have an old Meade 4000 32mm I picked up used many years ago. I don't use it now but it is very sharp. I'm thinking of putting it in my new finder for x7 and 7°

[bosun21]

2 hours ago, John said:

FWIW I use a Vixen NPL 30mm for that use. I got it for peanuts pre-owned but it works well in all my scopes, even at F/6.5. 

I compared the Vixen NPL 30 with a Baader 32 a while (over 10 years now 😬) back. Both were pretty decent but I preferred the Vixen:

Baader Classic 32mm Plossl meets Vixen 30mm NPL Plossl - Member Equipment Reviews - Stargazers Lounge

That was way before FLO introduced the UFF's and others to their range of course.

 

I've owned the Vixen NPL30 and as you say I found it optically good, however I just couldn't get on with the plastic eye relief adjustment on it. It was very loose and kept slipping back down. I ended up putting an elastic band around it. It's a pity as I did like it.

[John]

1 hour ago, bosun21 said:

I've owned the Vixen NPL30 and as you say I found it optically good, however I just couldn't get on with the plastic eye relief adjustment on it. It was very loose and kept slipping back down. I ended up putting an elastic band around it. It's a pity as I did like it.

Yes, I can see that mine will wear out at some point. For the tenner that it cost though, I can live with an elastic band 🙂

Edited June 4 by John

[bosun21]

35 minutes ago, John said:

Yes, I can see that mine will wear out at some point. For the tenner that it cost though, I can live with an elastic band 🙂

I think I just had a particularly poor NPL30. I have however come across others who experienced the same problem and went about resolving the problem by differing means. I also have the Celestron Omni 32mm 50° plossl which to my eye is equally as good. It gets good feedback on CN as well. £20 plus £3.39 postage on flea bay for brand new specimens.

[John]

5 minutes ago, bosun21 said:

I think I just had a particularly poor NPL30. I have however come across others who experienced the same problem and went about resolving the problem by differing means. I also have the Celestron Omni 32mm 50° plossl which to my eye is equally as good. It gets good feedback on CN as well. £20 plus £3.39 postage on flea bay for brand new specimens.

The longer focal length Omni's are decent eyepieces. I've had a couple of really rotten short FL ones though, which rather put me off them. In one instance I dismantled the eyepiece to find that one of the doublet pairs had not been cemented together properly which led to blurring of the image whatever I tried. To be fair though I had a similar issue with a Meade 4000 short FL plossl many years back so these things do happen in mass production.

I agree that the eyecup implementation in the NPL 30 is not great though. They improved it a lot for the SLV range but the RRP of those is substantially more !

Optically I believe the NPL's use the Tele Vue plossl's approach of slightly concave outer lens surfaces to achieve slightly sharper views across more of field in faster scopes. Probably not as fast as F/4 though, which Tele Vue claim for their eyepieces !

 

[Roy Challen]

I did like the Vixen 30mm NPL optically, but like others, thought the eyecup could've been better. Also I got horrendous reflections when using it for solar. Maybe the eyecup design was even responsible for that too, although it was fine at night.

The Baader 32mm plossl on the other hand may as well be welded to my Daystar, it's better in every way imo.

I owned them at the same time so was able to make a direct comparison.

Edited June 4 by Roy Challen

[John]

1 hour ago, Roy Challen said:

I did like the Vixen 30mm NPL optically, but like others, thought the eyecup could've been better. Also I got horrendous reflections when using it for solar. Maybe the eyecup design was even responsible for that too, although it was fine at night.

The Baader 32mm plossl on the other hand may as well be welded to my Daystar, it's better in every way imo.

I owned them at the same time so was able to make a direct comparison.

Thats interesting. I tried my NPL  30 for white light solar with the 1.25 inch Lunt HW and my Vixen ED102SS refractor and it was good with no odd reflections, eye cup up and down. I tried it in a Lunt 60 H-alpha at the weekend and it didn't do well - I did see reflections in that. I wondered if it was the intense filtering used in the Lunt H-alpha scope ?

 

 

[Second Time Around]

With a Quark working at f/26 I did head to head tests between the 32mm Televue, a 32mm GSO clone, the Baader 32mm and the 30mm Vixen NPL Plossls.  Prominences are a very stiff test for eyepieces and I could see no difference between any of them.

The one I kept was the NPL because the adjustable eyecup makes it the most comfortable for me.   Everyone is different, but I need the eyecup about half way up.  

I found an elastic band works, but a doubled up hairgrip holds better and is easily adjustable.