16 replies to this topic

[CQDDEMGY]

I have 2 refractors 120mm f/5 and a 102 f/7.  Looking to finish my eyepiece set while I still can.

 

I have:

Astro-Tech 28mm UWA 82°

Meade 20mm UWA 82°

Meade 8.8 UWA 82°

Meade 5.5mm UWA 82°

 

I will be getting an Agena 2" Super Wide Angle (SWA) Eyepiece - 38mm.  Yes I know what this eyepiece is, and I am good with it.

 

I will probably purchase Astro-Tech 4mm UWA 82°  and in the same line am not sure if the 16,13 or 10 would be the best choice.  The 28mm is a tremendous eyepiece, and the price is right on this line, that's why I am looking at them.  

[Jay_Reynolds_Freeman]

The 13 mm looks like the best fit between 20 and 8.8. How well do the Meade UWAs work at f/5?

 

Clear sky ...

[CQDDEMGY]

I enjoy them.  Field curvature is a bigger problem than issues with the eyepiece.

[vtornado]

Why are you getting a AA 38/70 when you have a 28/82?

 

The field of view will be a little bit wider in the 38, but that extra field will be very distorted at f/5.  Assuming you are in light pollution city being in Detroit, (I'm outside Chicago) the sky will be extremely grey.

 

A wider field will also have more field curvature.

 

I have all of the AAs 70 series.  I use them for public out reach because the exit pupil is easy for a novice to find and hold.  I don't use the 38 very often.  It's usually the 32 and 26.

[CQDDEMGY]

It weighs less than the 28/82.  I have to rebalance my scope to use the 28/82.  

 

My understanding is AA 70 is a GSO superview, in my experience they are solid at f/6.

 

And I want it for a 80mm f/5.

[Mark Lovik]

I started with AA 26mm and 32mm 70's for an SCT.  These were solid choices for my use at the time but are now relegated to outreach use.  The AT28mm 82 is that much better, and works well in my local suburban skies.  

 

I really like the AT28 on my F/6 and F/7 fracs.  It's about my measured exit pupil limit at F/6 and works well as a finder/sweeper eyepiece on all my scopes.

 

The longer focal length of the AA 38mm 70 seems inappropriate for an F/5 frac with an exit pupil over 7mm. Have you measured your exit pupil to see if your eyes can handle this combination?  If your eyes are not good enough ... it just drops the effective aperture of the eyepiece/scope combination, but it may not have the performance you are hoping for.

 

I have a number of the shorter AT UWA series of eyepieces, and these are all good choices.  I really like the eyepieces - 28mm down to the 4mm are very parfocal (at least with my AT diagonal and 2-1.25 adapter).  Almost no refocusing is necessary when swapping eyepieces in this line.  The optics are great ... but sometimes it's the little unexpected extras that make your day.

 

I also use these eyepieces on my Quattro 150P at F/4.  The 28mm is too long for my eyes and this focal ratio, but it works as a finder eyepiece.  The AT UWA's still perform reasonably well for this scope.  Yes this is not a frac ... but it's one of my two fastest scopes at F/4.

Edited by Mark Lovik, 19 May 2025 - 12:32 PM.

[SeattleScott]

If weight is the issue, and F5 is the F ratio, then the 30UFF would seem to be the answer. Approximately the same weight as the 38mm SWA, with better exit pupil and edge correction. It also won’t show as much field curvature from the scope due to the smaller field stop. Granted, the view will be a bit narrower than the 38mm, but it will be much cleaner and less washed out.

The 13UWA is the obvious fit between 8.8 and 20. I hear it isn’t as well corrected as some others in the series, but the OP doesn’t seem to care too much about edge correction as long as the price is right.

There is a 14mm 70 AFOV available under various brand names that is supposed to be a good value pick. I would guess it has a bit better ER and edge correction than the 13UWA, but at the cost of just 70 AFOV instead of 82. So does one want a wider field, or a cleaner field?

[CQDDEMGY]

Before I bought the 28/82 I considered the 30UFF. It was significantly more costly and I was unable to find a US source so it would have to be imported.

Looks like the 13/82 is it.

[Mike W]

Before I bought the 28/82 I considered the 30UFF. It was significantly more costly and I was unable to find a US source so it would have to be imported.

Looks like the 13/82 is it.

Celestron 30UFF on Amazon.

[T1R2]

The 38/70* will be a terrible match for the f5 80mm. I mean if you're viewing a 5* long comet it might be ok...but man-o-man it is gonna be ugly 1/2 way out from the center. 

[CQDDEMGY]

38/70 in a 80 f/5 will give a greater field of view than some binoculars I have owned.

I also have a f/7 scope.

[SeattleScott]

It will give a wide view, it will just be messy. As opposed to a narrower view but clean (for a bit more money). Really just personal preference, as long as you understand the trade off.

[Jon Isaacs]

38/70 in a 80 f/5 will give a greater field of view than some binoculars I have owned.

I also have a f/7 scope.

 

My thinking:

 

It won't be pretty, the exit pupil will be 7.6 mm.

 

But it will only cost about $100 and provide very wide, fields of view and will be most useful with O-lll, UHC and H-Beta filters where the edge correction doesn't really matter.

 

And it will maximize the TFoV of the 102 mm F/7.

 

It's not a 41 mm Panoptic but it doesn't cost $600... I've owned the 32 mm 70°, used it at F/5. It's not a 31 mm Nagler but that didn't prevent from enjoying the views. 

 

Jon

[jrmacl]

My thinking:

 

It won't be pretty, the exit pupil will be 7.6 mm.

 

But it will only cost about $100 and provide very wide, fields of view and will be most useful with O-lll, UHC and H-Beta filters where the edge correction doesn't really matter.

 

And it will maximize the TFoV of the 102 mm F/7.

 

It's not a 41 mm Panoptic but it doesn't cost $600... I've owned the 32 mm 70°, used it at F/5. It's not a 31 mm Nagler but that didn't prevent from enjoying the views. 

 

Jon

Totally agree. At first I was like what is he talking about- then I saw it was only a $100 eyepiece and thought why not, go for it.

[aeajr]

It weighs less than the 28/82.  I have to rebalance my scope to use the 28/82.  

 

My understanding is AA 70 is a GSO superview, in my experience they are solid at f/6.

 

And I want it for a 80mm f/5.

I have the AA 38/70.  Same as the Orion Q70 with a different label.  It has been my 2" low power wide view eyepiece for 8 years and I have no plans to replace it.  

 

It is not a GSO Superview.  I forget who makes them, but it is not GSO.  However I believe they are both considered Erfle type designs.  I have used the The Superview eyepieces.  They are lighter in weight.  However, I like the AA SWA better.

 

 

I use mine in F5 12" Dob and a 102 mm F7 ED refractor.  Gets the job done. 

 

My buddy has a 10" F4.7 Dob and after using mine he bought one.

 

I use it to:

• Max out the field of view
• Sweep the Sky
• Find my targets
• Observe very large targets at very low power. 

If I were to upgrade from this I would probably go for an ES 68/40, but I don't feel the need to spend all of that money for a low power wide view eyepiece.

 

I have read all of the criticisms of this eyepiece and, for the most part they are accurate, if you are a very discerning user.  However as a low cost wide view solution, it gets the job done for me.  But I don't typically spend a lot of my observing time with this eyepiece.  I go to my Baader Hyperion 8-24 zoom most of the time, or my Meade and ES 82s.

 

Most nights I pull out the AA 38/70, BH 8-24 Zoom and a Barlow as the only eyepieces I use for the session. I might switch to the ES 82s when I get above 300X, for more drift time. 

Edited by aeajr, 20 May 2025 - 03:00 PM.

[Jon Isaacs]

Totally agree. At first I was like what is he talking about- then I saw it was only a $100 eyepiece and thought why not, go for it.

 

 

I like some balance and perspective. I've been fortunate and been able to acquire eyepieces likes the 41 mm Panoptic. But one does not need eyepieces like that to enjoy viewing the universe.

 

40-50 years ago, eyepieces like that did not exist but people still observed with 5 inch F/5 Jaegers achromats.

 

I like to have eyepieces that are basic like the Q-70s. They help me keep that perspective.. 

 

I think you'll enjoy your 38 mm.. you have realistic expectations.

 

Jon

[Tropobob]

I recommend a 15mm as a useful supplement to the other eyepieces. 

 

Many observers enjoy using eyepieces with an exit pupil of 2mm or 3mm and a 15mm will tick both these boxes with the F7 and F5 scopes respectively. 

 

I have previously owned a 100mm F5 scope, and I found that I enjoyed it most when using a 15mm EP. 

 

That said, a 16mm EP will be much the same if that is preferred.