Axiom LX 23mm..a real Dark Horse?

[F15Rules]

I used to own a wonderful Vixen LVW 22mm eyepiece..it was, IMHO a pretty much perfect low power, widefield eyepiece, and in my FS128 it gave me my best ever view of M42, just stunning.

Sadly, I had to sell it shortly after I got my Tak (in spring 2017), as part of my kit sell off to help fund the Tak scope and Tak mount. 

Since then, finding another has been pretty much impossible, and those that do have one seem determined to keep it, as they realise just what a gem they are.

This does sometimes happen: a readily available branded product can be somewhat overlooked, and only after it has been discontinued does it begin to be properly and widely acknowledged for the great performer it is..the Baader Genuine Ortho range also springs to mind, and I think the Vixen LVW range is another...all sizes were and are great performers, with a nice 65 degree fov and good eye relief.

Anyway, some months ago, I saw an advert for a Celestron Axiom LX 23mm 2" 82 degree eyepiece, and found some positive reviews/opinions both here on SGL and on the US site. I still really wanted a decent low power widefield giving me c 40-50x in the FS128 (FL 1040mm, F8.1), so I decided to give it a try and bought it.

Over the past few months I've had about half a dozen sessions using the Axiom 23mm, and I have to say I'm delighted with it. It's a big, heavy eyepiece, twice the heft of the Vixen LVW 22mm, and only useable in 2" focusers, but the key positives I've identified are:

- Excellent fit and finish. Built to last and optics have very good coatings.

- Built in rotating eyecup, which makes it easy to find a comfortable observing position

- very wide, immersive 82degree field of view, which is sharp virtually to the edge of the fov in the FS128 (95% plus).

- good colour rendition..eg Albireo, showing great contrast and beautiful colour shades in a "spacewalk" field

- comfortable in use

Potential issues:

- needs a robust focuser due to the weight (926g)

- 2" barrel so not useable straight into 1.25" focusers**

I spent time observing mainly M42, The Double Cluster in Perseus, and the Pleiades.

- in good clear, dark skies M42 was stunning. Just as sharp and contrasty as the LVW 22mm, but the extra 17 degree fov (82 vs 65) of the Axiom really added impact to the view..with M42 centred in the field, the Iota Orionis system was clearly visible out towards the edge of the field, with room to spare.

- we've all been entranced by the Double Cluster, I'm sure. I'm no different, it's always one of the first things I look at when it's well placed..but I've never seen it as I've seen it through the Ax 23mm. Both clusters superbly framed with room to spare, with hundreds of tiny, scintillating points of light all over the field. I think the phrase I've heard more often used to describe this object than any other is "diamonds sparkling on velvet"..I couldn't put it any better myself.

- The Pleiades. With an apparent field of 1.83 degrees I could just about fit the main asterism into the Axiom 23mm field (1.82 degrees)..

The nebulosity around Merope and the other brightest stars was quite evident, and the lovely line of 7th magnitude stars extending down to the southeast from the main grouping was beautifully sharp.

So, in summary, I do believe I've found a worthy replacement for the Vixen LVW22..actually, taking the extra field into account, even a little better?

Photo shows the eyepiece decloaked, but I've recloaked it for comfort reasons.

NOTE: **2" barrel so not useable straight into 1.25" focusers**.. I have found I can use this ep in a 1.25" focuser by using a Baader prism with 1.25" nosepiece on the scope end and a 2" Clicklock on the eyepiece end. This can cause some vignetting but the views are still very nice. Better still is if you can attach a T2 adapter to your focuser and thread the male T2 thread into a Baader BBHS Zeiss prism..this has a 34mm clear aperture vs 32mm on the standard T2 prism. The Axiom 23mm field stop is also  34mm, so the BBHS prism will fully illuminate the Axioms' fov with little or no vignetting.

Mine's definitely a keeper!👍

Dave 

PS: I see there's a 23mm Axiom LX for sale right now on UKABS..nothing to do with me, but sounds like a bargain!

 

 

Edited February 7, 2022 by F15Rules
Photo added, additional text info added

[Louis D]

23 minutes ago, F15Rules said:

Potential issues:

- Insufficient eye relief for eyeglass wearers.

I can just barely see the entire field of the original 30mm ES-82 mushroom top (same JOC made eyepieces as the Celestron Axiom LX and the original Meade 5000 UWA) wearing eyeglasses.  Being a scaled design, the 23mm would put the FOV just out of reach.

At least for the 30mm version, it has strong ring of fire and some very minor edge astigmatism in the last 10% of the FOV at f/6.  Stars are also not as pinpoint in the central 50% as the 27mm Panoptic or even the 30mm APM UFF.  Stars remain a bit bloated in comparison at best focus.  It's why I keep all of them.  Each has its strengths.  Have you compared the 23mm to a 24mm Panoptic or similar for central sharpness?

It does have a perfectly flat field even to my presbyoptic eyes.  I assume the 23mm is the same way.

[F15Rules]

Fair comment about possible eye relief issues..the quoted eye relief on the 23mm is 17mm, which as a non glasses wearers for observing is very comfortable for me.

The 23mm has no ring of fire that I can detect. The 31mm  Axiom LX has a bluish thin ring around the edge in daytime , but I can't detect it at night, which is what matters to me, plus I'm reviewing the 23mm here, not the 31mm.

9 hours ago, Louis D said:

Stars are also not as pinpoint in the central 50% as the 27mm Panoptic or even the 30mm APM UFF.

I've never used either of those eyepieces so can't comment on them.. However, I have 9mm and 17.5mm Morpheus and a Nagler 12mm T2, and I can say that the Axioms' on axis sharpness gives up nothing to any of these, it's every bit as sharp.

9 hours ago, Louis D said:

Stars remain a bit bloated in comparison at best focus.  It's why I keep all of them

Well, it's each to their own of course, but I couldn't afford to keep several different eyepieces of the same or very similar focal lengths..I'd just buy the one that got as near to being perfect for me and my scopes as I could afford🙂.

Dave

[Saganite]

2 hours ago, F15Rules said:

 

Well, it's each to their own of course, but I couldn't afford to keep several different eyepieces of the same or very similar focal lengths..I'd just buy the one that got as near to being perfect for me and my scopes as I could afford🙂.

Dave

Me neither, particularly as I need two of everything, but I agree,  just  what you consider the best of the ones tried would be enough for me also.

The Axion 23mm sound like a very good alternative .

Edited February 7, 2022 by Saganite

[Highburymark]

Nice report Dave.
I think we probably ask more of our 20-25mm widefield eyepieces than any other focal length. Framing open clusters right to the field stop makes aberrations very noticeable. Sounds like the Axiom is an excellent alternative to the LVW.

[F15Rules]

Thanks Mark.

Yes, I think you're right..every session I observe I follow a pattern to start with, of lowest power (finder scope!), then 23 - 31mm, 17.5mm, (12mm), 9mm to (5mm).

The two in brackets depends on the object I'm observing and the sky conditions. All of my eyepieces can also be barlowed if need be.

The main difference I noted with the 23mm Ax vs the 22mm LVW was the extra width of the sharp field. Although the LVW was sharp in my Tak right to the edge (ie the full 65degrees, the Ax23 is sharp to c 96-97%at least, and that percentage equates to at least 78, degrees, so right up with the best Morpheus field.

The 31mm also performs well, but I haven't used it as much as yet so will report on that later, when I've been able to put it through it's paces 

Dave

[F15Rules]

Further to this thread on the Axiom LX 23 and 31mm (both of which I have, and like very much, I found this really detailed review on CN USA. A really good read for its own sake, and very useful if you'd love a Nagler 31mm, will never be able to afford one, and can't decide if the Axiom LX could possibly be in the same league as the Terminagler 31...

https://www.cloudynights.com/articles/cat/user-reviews/eyepieces/eyepieces-14mm-55mm/the-ax-files-r1827

Enjoy,

Dave

[cajen2]

These EPs have been replaced by the Luminos range, I believe? Are they as good?

Anyone wanting a wide FOV 20ish mm 2" EP should also consider the StellaLyra (= Orion = Long Perng) 80°LER/UWA . I have one and it's one of my favourite EPs. Because it's 80°, it has almost exactly the same FOV as my 30mm Vixen NPL - the EP I used to start every session as a finder. Of course, the SL has more mag and is thus more versatile. Stars are pinpoints across the whole field and contrast is excellent.

Edited September 4, 2022 by cajen2

[Guest]

I can second what Cajen2 said about the SL 20mm.  The only issues i have with it is that weird screw on end cap, but for the views it returns, I can live with that oddity.   Some people complain about the eye relief with glasses, for the wife and i its a non-issue, we take them off and focus the scope.  

[cajen2]

The eye relief is 20mm. Even taking the slight recess of the top lens into account (which EP manufacturers strangely often don't 😉) it's well long enough even for glasses wearers - I estimate about 17mil.

The 'screw on end cap' is a normal screw up and down eyecap, which Mike doesn't like for some reason!🤣

Edited September 4, 2022 by cajen2

[Guest]

Its more screw on and off lol.  I don't get it.  They make the perfect eyepiece and put a [removed word] end cap on.  For 95% percent of people its a non-issue, but it drives me nuts. 

[cajen2]

You always were weird, Mike! 😉😄😄

Any number of manufacturers use the same system: it gives fine control of the eye relief.

Edited September 4, 2022 by cajen2

[Guest]

Oh you have met me lol

[F15Rules]

2 hours ago, cajen2 said:

These EPs have been replaced by the Luminos range, I believe? Are they as good?

Anyone wanting a wide FOV 20ish mm 2" EP should also consider the StellaLyra (= Orion = Long Perng) 80°LER/UWA . I have one and it's one of my favourite EPs. Because it's 80°, it has almost exactly the same FOV as my 30mm Vixen NPL - the EP I used to start every session as a finder. Of course, the SL has more mag and is thus more versatile. Stars are pinpoints across the whole field and contrast is excellent.

Yes, the Luminos were intended to replace the Axioms..however, the consensus is that while there is less visible difference between the short focal length Luminos' Vs their Axiom equivalents, the longer focal length Luminos' are not as good as the Axioms, especially in 23mm and 31mm versions. Different manufacturers, with the Luminos meant to look like the Axioms but different innards..

I did own a 7mm Axiom for a time and it was excellent..I'd buy another if one came up.

Dave

[Louis D]

IIRC, reports on the Luminos complained about excessive EOFB (Edge of Field Brightening) which makes the outer field appear brighter and cloudier than the inner area, and also excessive SAEP (Spherical Aberration of the Exit Pupil) or kidney beaning which makes holding the exit pupil tiring.  Some folks swear by them rather than at them, though, so YMMV.

As far as the Axiom LXs, they were the same optically as the Meade 5000 UWA and original ES-82 mushroom tops.  All were made by JOC.  I have the 30mm ES-82 decloaked, and it is just barely usable with eyeglasses.  While the 82 degree field is rewarding to look at, stars are a bit bloated across the field compared to others I have in this range, and especially near the edge as CAEP (Chromatic Aberration of the Exit Pupil) kicks in.  The moon turns orange in the outer field as a result, and planets split into red/blue slightly separated version of themselves.  Thus, for those of us with undriven scopes who enjoy observing objects drifting from edge to edge before nudging again, the 30m ES-82 doesn't really work for that use case.

[Louis D]

21 hours ago, Mike Q said:

 Some people complain about the eye relief with glasses, for the wife and i its a non-issue, we take them off and focus the scope.  

If only I could simply turn a knob and "focus" out my strong eye astigmatism.  I have no desire to get LASIK, either.

[Guest]

6 minutes ago, Louis D said:

If only I could simply turn a knob and "focus" out my strong eye astigmatism.  I have no desire to get LASIK, either.

Just out of curiosity have you ever tried using the weak eye?  I have tried it and had to use an eyepatch to make it work.   

Edited September 5, 2022 by Mike Q

[cajen2]

2 minutes ago, Mike Q said:

Just outnof curiosity have you ever tried using the weak eye?  I have tried it and had to use an eyepatch to make it work.   

I believe you're just waiting for the parrot and tricorne hat to complete the ensemble, Mike? 😉

[Guest]

1 minute ago, cajen2 said:

I believe you're just waiting for the parrot and tricorne hat to complete the ensemble, Mike? 😉

Dont forget the flintlock pistol and saber lol.  I gave it a go once, talk about different.  Did the same thing once with the rifles with optics.  That was a struggle

[Louis D]

5 minutes ago, Mike Q said:

Just out of curiosity have you ever tried using the weak eye?  I have tried it and had to use an eyepatch to make it work.   

The difference in astigmatism is minor.  2.00 on the left, 1.75 on the right.  I'm left eye dominant, which has made using SLRs/DSLRs a pain over the years because they shift the viewfinder left assuming right eye dominance to make room for the nose.

[Guest]

2 minutes ago, Louis D said:

The difference in astigmatism is minor.  2.00 on the left, 1.75 on the right.  I'm left eye dominant, which has made using SLRs/DSLRs a pain over the years because they shift the viewfinder left assuming right eye dominance to make room for the nose.

Left eye dominant here too, no real astigmatism at this point just need reading glasses at this point. I feel for you guys that have real issues. 

[Don Pensack]

On 04/09/2022 at 09:21, cajen2 said:

The eye relief is 20mm. Even taking the slight recess of the top lens into account (which EP manufacturers strangely often don't 😉) it's well long enough even for glasses wearers - I estimate about 17mil.

The 'screw on end cap' is a normal screw up and down eyecap, which Mike doesn't like for some reason!🤣

Its design sacrifices 8mm of the 20mm eye relief when all the way down!

It's a long eye relief eyepiece with the eyecup removed.

I would find another regular eyecup of 49-50mm I.D. to replace the original eyecup with glasses.

Without glasses, the OE eyecup works great.

[cajen2]

I'm sure you're right - all I can say is there's plenty of ER for me and I sometimes wear glasses. What concerns me more is that quoted ER in manufacturers' official specs is very often the distance above the lens, not above the eyecup.

Edited September 5, 2022 by cajen2

[Don Pensack]

3 minutes ago, cajen2 said:

I'm sure you're right - all I can say is there's plenty of ER for me and I sometimes wear glasses. What concerns me more is that quoted ER in manufacturers' official specs is very often the distance above the lens, not above the eyecup.

It is always the distance up from the center of the top surface on the eyelens, the paraxial eye relief.  I have also called it the Design eye relief, as the housing is usually not externally designed as the lens configuration is designed.

IF the manufacturer quotes the eye relief correctly, measuring the depth of the lens will tell you the eye relief from the folded down rubber eyecup to the exit pupil, the "effective" eye relief for glasses wearers.

See this discussion:

https://www.cloudynights.com/topic/837363-effective-eye-relief-a-few-measurements/

 

[cajen2]

My point precisely. "IF the manufacturer quotes the eye relief correctly..."