Orthoscopic vs wide field.

[quasar117]

8 hours ago, John said:

I've not used a UFF myself but I believe that the 30mm is a slightly better performer than the 24mm although that is also a very nice eyepiece. The 2 inch 30mm shows a considerably larger true field of view of course. 

I use 2 inch diagonals in all my refractors now so I can pop in a 2 inch eyepiece when I want a really wide view. For medium to high powers though I'm usually using 1.25 inch eyepieces, though not always.

That is the main benefit of the 2 inch fitting - the wider field of view than the 1.25 inch format can deliver.

 

Looking on FLO there is a £90 difference between the 30mm Celestron Ultima and Stellarlyra 30mm UFF. Correct me if I'm wrong but I believe the eyepieces are more or less identical save for the branding?

[Zermelo]

13 minutes ago, quasar117 said:

Looking on FLO there is a £90 difference between the 30mm Celestron Ultima and Stellarlyra 30mm UFF. Correct me if I'm wrong but I believe the eyepieces are more or less identical save for the branding?

Of the various UFF brandings, the Celestron versions are at the pricier end.
Compare the 10mm: Celestron £149; Svbony is currently a little under £50, but I bought mine for less than half of that, in one of their frequent sales.
Now, if only they offered the 24mm or 30mm...

[cajen2]

24 minutes ago, quasar117 said:

Looking on FLO there is a £90 difference between the 30mm Celestron Ultima and Stellarlyra 30mm UFF. Correct me if I'm wrong but I believe the eyepieces are more or less identical save for the branding?

Yes, I have the Ultima Edge 30mm, which I bought just before the SL range was introduced 🙄 and I'm reliably informed is optically the same EP, though the CUE is prettier! So yes, buy the SL: you won't regret it - an excellent EP.

[quasar117]

1 hour ago, cajen2 said:

Yes, I have the Ultima Edge 30mm, which I bought just before the SL range was introduced 🙄 and I'm reliably informed is optically the same EP, though the CUE is prettier! So yes, buy the SL: you won't regret it - an excellent EP.

Will the 30mm UFF vignette in a 2" William optics durabrite diagonal?

[Mr Spock]

3 minutes ago, quasar117 said:

Will the 30mm UFF vignette in a 2" William optics durabrite diagonal?

Should be fine. I use it in a Baader T2 which is an undersized prism and it's ok in that.

[cajen2]

36 minutes ago, quasar117 said:

Will the 30mm UFF vignette in a 2" William optics durabrite diagonal?

No, I have the same EP and 2" WO diagonal. It's fine.

[quasar117]

When testing the 30mm UFF on FOV simulator it's 24x mag with the Starfield. That certainly gives a wide view!  Would the 24mm UFF be a better option for framing the showpiece Messier objects and the moon? Or is the 30mm that much more superior in providing better correction and a flatter field?

[Mr Spock]

34 minutes ago, quasar117 said:

Or is the 30mm that much more superior in providing better correction and a flatter field?

Once you've seen the Pleiades through the 30mm you'll be convinced  As well as framing all the stars you can see the nebulosity too - even in my LP.

[quasar117]

Looks like I'll be getting the 30mm UFF then 😅 that blows the budget.... better not tell the wife haha

[Louis D]

I have both the 24mm and 30mm APM UFFs.  The 30mm is the better of the two.  The biggest issue I have with the 24mm is that the field stop is fuzzy and the last 3% or so of the field is also fuzzy and vignettes.  Basically, the designer pushed the design just a little to far for largest possible true field of view.  If I had a tracking mount, I might not notice the edges so much.

[Louis D]

7 hours ago, Roy Challen said:

This is what I do, no faff at all. Some say a manual alt-az is less faffy, I disagree 😁. My EQ mount is much heavier though...

I took a hard pass on a 127 Mak at a good price on an EQ mount with counterweights a decade ago.  I could barely lift it one handed due to the weight and top-heaviness of it.  I need to be able to pick up and move my mount and scope around the yard to dodge obstructions, so this weight and bulk issue was a non-starter for me.

[Roy Challen]

14 minutes ago, Louis D said:

I took a hard pass on a 127 Mak at a good price on an EQ mount with counterweights a decade ago.  I could barely lift it one handed due to the weight and top-heaviness of it.  I need to be able to pick up and move my mount and scope around the yard to dodge obstructions, so this weight and bulk issue was a non-starter for me.

My EQ setup is about 18-19kg so needs both hands to lift, as I also need to move around the garden occasionally. But actually setting up and tracking is just as quick as alt-az. I was being slightly tongue in cheek, hence the smiley face😉.

It's worth it as it allows high power tracking while using orthos, or other narrow field designs, even in strong winds.

Edited March 4 by Roy Challen

[Don Pensack]

16 hours ago, quasar117 said:

Since I'm planning on buying a 2" diagonal, would the Stellarlyra 30mm UFF be superior to the 24mm UFF?

Or is it pointless getting a 2" diagonal if I can get excellent low power wide eyepieces in 1.25" format?

The 30mm UFF is a better eyepiece than the 24mm in some ways, and it will give you a true field 31.5% wider than the 24mm.

That wider field at lower power will:

--be more bothered by telescope field curvature--especially in a refractor

--have a much brighter sky background in the eyepiece if you are in a light polluted area

So it might not be a better eyepiece for you than the 24mm.  It depends on your circumstances.

[mikeDnight]

4 hours ago, quasar117 said:

When testing the 30mm UFF on FOV simulator it's 24x mag with the Starfield. That certainly gives a wide view!  Would the 24mm UFF be a better option for framing the showpiece Messier objects and the moon? Or is the 30mm that much more superior in providing better correction and a flatter field?

Sometimes the choice of eyepiece can be made on the basis of sky darkness. With the 30mm (mine is the Altair Astro version), the sky background may be too bright to allow for high contrast views of some DSO's, so dropping down from 30mm to 24mm can greatly improve contrast and the ease with which more intricate detail can be seen. Years ago my friend Derek had an obsession about low power, wide field viewing. His telescope was a 102mm F6.5 Vixen ED - a remarkable telescope IMO!  We were looking at the Orion Nebula, and I almost had to break his arm for him to allow me to put my 20mm Nagler into his scope. His reaction was explosive, but in a good way. The sky background in the 102 F6.5 and 20mm combination was dark, while the diamond dust stars and the nebula itself stood out as if in 3D. So basically you need both, or even better the entire set. It's only money!

[John]

1 minute ago, mikeDnight said:

Sometimes the choice of eyepiece can be made on the basis of sky darkness. With the 30mm (mine is the Altair Astro version), the sky background may be too bright to allow for high contrast views of some DSO's, so dropping down from 30mm to 24mm can greatly improve contrast and the ease with which more intricate detail can be seen. Years ago my friend Derek had an obsession about low power, wide field viewing. His telescope was a 102mm F6.5 Vixen ED - a remarkable telescope IMO!  We were looking at the Orion Nebula, and I almost had to break his arm for him to allow me to put my 20mm Nagler into his scope. His reaction was explosive, but in a good way. The sky background in the 102 F6.5 and 20mm combination was dark, while the diamond dust stars and the nebula itself stood out as if in 3D. So basically you need both, or even better the entire set. It's only money!

Exactly why I use my 21mm wide field eyepiece much more often than my 31mm wide field. If I had to live without one of them (which I don't thank goodness !) I'd have to let the 31mm go.

 

 

Edited March 4 by John

[quasar117]

2 hours ago, mikeDnight said:

Sometimes the choice of eyepiece can be made on the basis of sky darkness. With the 30mm (mine is the Altair Astro version), the sky background may be too bright to allow for high contrast views of some DSO's, so dropping down from 30mm to 24mm can greatly improve contrast and the ease with which more intricate detail can be seen. Years ago my friend Derek had an obsession about low power, wide field viewing. His telescope was a 102mm F6.5 Vixen ED - a remarkable telescope IMO!  We were looking at the Orion Nebula, and I almost had to break his arm for him to allow me to put my 20mm Nagler into his scope. His reaction was explosive, but in a good way. The sky background in the 102 F6.5 and 20mm combination was dark, while the diamond dust stars and the nebula itself stood out as if in 3D. So basically you need both, or even better the entire set. It's only money!

I live in supposed Bortle 5 skies but all my observing is from the backyard and it isn't always reliably dark due to neighbours sensor patio lights etc.

Would I be better off with the 24mm for now then as I can't afford both?

 

[quasar117]

Having read a few other threads regarding the 24mm UFF it appears the 30mm is sharper edge to edge. That sways me back towards the 30mm.

[mikeDnight]

3 hours ago, quasar117 said:

I live in supposed Bortle 5 skies but all my observing is from the backyard and it isn't always reliably dark due to neighbours sensor patio lights etc.

Would I be better off with the 24mm for now then as I can't afford both?

 

I spent 20 years observing under similar circumstances. It's so important to shield peripheral light from entering your eyes as you observe, so even though you are surrounded by annoying lights, using a blackout hood or blanket greatly improves your ability to make out fuzzies well. So whichever eyepiece you choose, you'll get the best out of it. ☺️

Edited March 4 by mikeDnight

[JeremyS]

13 hours ago, mikeDnight said:

I spent 20 years observing under similar circumstances. It's so important to shield peripheral light from entering your eyes as you observe, so even though you are surrounded by annoying lights, using a blackout hood or blanket greatly improves your ability to make out fuzzies well. So whichever eyepiece you choose, you'll get the best out of it. ☺️

I think a ghost is sneaking a peak thru your Tak, Mike.

[bosun21]

13 hours ago, mikeDnight said:

I spent 20 years observing under similar circumstances. It's so important to shield peripheral light from entering your eyes as you observe, so even though you are surrounded by annoying lights, using a blackout hood or blanket greatly improves your ability to make out fuzzies well. So whichever eyepiece you choose, you'll get the best out of it. ☺️

I never go observing without my blackout drape. It makes so much of a difference for DSO's.

[Louis D]

@mikeDnight I assume you are using an Icarus filter to observe DSOs in the daytime? 😏

 

[mikeDnight]

4 hours ago, JeremyS said:

I think a ghost is sneaking a peak thru your Tak, Mike.

Either that, or John Merrick has taken up astronomy!

[Captain Scarlet]

5 hours ago, JeremyS said:

I think a ghost is sneaking a peak thru your Tak, Mike.

No I think it’s doing what Taks do best - drying rack! 😉

[quasar117]

Would the ES 24mm 68 degree be a better option than the 24mm UFF?

I think due to light pollution in my area the 24mm would be a better choice than 30mm for my low power eyepiece.

 

[Don Pensack]

5 hours ago, quasar117 said:

Would the ES 24mm 68 degree be a better option than the 24mm UFF?

I think due to light pollution in my area the 24mm would be a better choice than 30mm for my low power eyepiece.

 

That depends.

If you wear glasses, the UFF. 27.6mm field stop.  The field stop is pushed a bit, so it may be out of focus for your eye, but that really doesn't matter if used on deep sky objects.

       It's probably too low a power for Moon and planet observing anyway.

If you want the sharpest star images in the outer field, the 24mm Panoptic.  27.0mm field stop.  No astigmatism at the edge.

If you want the widest field possible in a 1.25" eyepiece, the 24mm Hyperion (also glasses compatible). 28.0mm field stop.  Lots of astigmatism in the outer field, however.

If you want a sealed waterproof eyepiece, the 24mm 68° ES.  27.2mm field stop.

 

Personally, I wear glasses and the 24mm UFF was fine in that regard, with about 17-18mm effective eye relief from the rubber up to the exit pupil.

And I found it sharp enough in my 4" f/7 scope.  I used it with a set of Tele Vue Delites and it fit right into the sequence.

I also appreciated that it was the only one of the 4 24mm eyepieces that had no undercut on the 1.25" barrel.

That made it far easier to insert and remove.

Also, if you pan the scope, the distortion profile makes this one the easiest to pan across the sky with.