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badhex

Ultra-low power widefield EP recommendation

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57 minutes ago, Pete Presland said:

I owned a Vixen 2" 42mm LVW, it was a good performer in my C9.25. Nice and lightweight, pretty sharp across most of the field of view.

This puts the cat among the pigeons! I've done a bit more research in this EP and this fits pretty much all of my criteria except the price. Hmmm... can I pony up the extra 100eur...?
 

14 minutes ago, old_eyes said:

Apologies. This is labelled OVL rather than skywatcher, but I assume it is the same. Yes, I thought I had clicked on 40mm to check availability, but I must have missed. I would email FIrstLight Optics and see what they say. Lots of items have gone onto long back order due to COVID19, but will be supplied in future (I am currently waiting for a NB filter that is delayed until at least November).

No worries! TBH I have been looking at them on so many sites that I've lost track of which branding is on which site :) I contacted FLO and they said it's discontinued with no known re-release or alternative sadly.


So right now I've narrowed it down to a couple of choices. Do I spend the ~120eur for the 35mm Aero ED, OR plump for the ~2.5 times more expensive Vixen?! Aagh!

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21 hours ago, Louis D said:

According to Ernest in Russia who tests many eyepieces on his optical test bench, the 35mm falls somewhere between the 40mm and 30mm.  You can look on his summary page for United Optics, ED toward the bottom of the table.  I've tried to repeat it below.  The numbers reflect the size of the blur spot of an artificial star at center/70%/98% to the field stop using an F4 and an F10 lens.  He moves the eyepiece to center the area of interest over the center of the lens image to eliminate lens aberrations influencing the results.  The actual full report page is here.  Try using Chrome browser to translate them.

  FL AFOV F4 F4 F4 F10 F10 F10 List of
Eyepiece mm °/deg. centre zone edge centre zone edge rest aberrations
United Optics, ED 40 64 5 18 25 <5 12 20 Ast.,FC
United Optics, ED 35 70 5 20 35 <4 12 20 Ast.,FC
United Optics, ED 30 66 5 20 40 <4 11 22 Ast.,FC

Oof.  That is poor edge performance even at f/10.  His measurements are in arc-minutes.  The predominant aberration is astigmatism.

These are not well-designed eyepieces, IMO.

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56 minutes ago, Don Pensack said:

Oof.  That is poor edge performance even at f/10.  His measurements are in arc-minutes.  The predominant aberration is astigmatism.

These are not well-designed eyepieces, IMO.

Are they not the same optics as the TMB Paragons ?

Maybe those rumours were incorrect ?

I find the 40mm pretty good for what it cost. The 30mm is OK at F/7.5 or slower. I use that mostly for outreach.

 

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3 hours ago, Don Pensack said:

Oof.  That is poor edge performance even at f/10.  His measurements are in arc-minutes.  The predominant aberration is astigmatism.

These are not well-designed eyepieces, IMO.

The 40mm Aero ED is well designed for it's price point.  It would be unrealistic to expect Panoptic 41mm correction for 20% of the price.

The 40mm Aero ED performs about as well as the 40mm Pentax XL, a bit worse than the ES-68 40mm offerings, way better than the GSO Super View, slightly better at the edge than the Vixen LVW 42mm, and better than the WO SWAN 40mm.  The Panoptic 41mm is indeed in a class by itself correction wise, though.  When you factor in weight, the Aero ED is a big winner for smaller scopes that are easily unbalanced.

United Optics, ED 40 64 5 18 25 <5 12 20 Ast.,FC
Pentax, XL 40 63.3 <2 18 28 <2.5 5 12 FC,Ast.
Explore Scientific, 68 40 68.7 <2(5) 22 40 <1.5 7 13 Ast. +16%
Explore Scientific, Maxvision 40 68.6 <3.5 25 40 3 8 12 Ast.,Coma,CA +15%
GSO, Super View 50 48 <7 45 65 4 20 32 Ast.,FC
Vixen, LVW 42 63 2 22 35 1.5 8 25 Ast.,FC +6%
William Optics, SWAN 40 65 <6 >25 >35 N/A N/A N/A Ast. 5%
Tele Vue, Panoptic 41 68 <2(7) 9 13 <2 6 8 Ast.,CA +17%
Edited by Louis D
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3 hours ago, Don Pensack said:

Oof.  That is poor edge performance even at f/10.

I guess maybe that it's probably a question of value for money. The full report states they "can be recommended to an observer who is not burdened with perfectionism for instruments with a 1: 8 relative aperture and less" but of course they aren't going to be at the top of their class.

In general, it seems like many folks are quite happy with the Aero 40mm which is what led me to them, but having never looked through one it's always hard to say, and I'm far from an EP expert so I'm relying on all you smart folks for your experiences! 

 

2 hours ago, John said:

Maybe those rumours were incorrect ?

I find the 40mm pretty good for what it cost.

From my last couple of days reading up the consensus seems to be that they are the same as the paragons but again, I'm just repeating what I've seen so it could be an eyepiece myth! 

 

What I find most interesting overall is that it seems like there's little to nothing else in the same price and quality range that is mostly praised. It seems like the next step up is most likely the Vixen, but at nearly 3x the cost. Others at the same price point seem to have varying degrees of praise. 

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51 minutes ago, badhex said:

What I find most interesting overall is that it seems like there's little to nothing else in the same price and quality range that is mostly praised. It seems like the next step up is most likely the Vixen, but at nearly 3x the cost. Others at the same price point seem to have varying degrees of praise. 

Thomas M. Back did a really good job designing the 40mm TMB Paragon, and then it was sold under other brands without permission.  The same thing happened to his TMB Planetary series.  He designed each to be as good as possible at a particular price point.  Apparently, he also designed the 30mm TMB Paragon.  However, it is unknown who did the 35mm version's design.  Did TMB design it but never release it under his TMB Paragon brand?  Did someone else extrapolate the design based on the 30mm and 40mm versions?

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Thomas Back's passing was a sad loss to astronomy.

Among many other things he designed the objective lens that sits in my 130mm F/9.2 triplet refractor. A really superb performer.

 

 

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23 hours ago, Louis D said:

Did TMB design it but never release it under his TMB Paragon brand?  Did someone else extrapolate the design based on the 30mm and 40mm versions?

Perhaps our Russian friend Ernest might be able to tell from the guts of the EP if the design is the same or merely very similar? I wonder if anyone here speak Russian and could find out, or if it will just be one do those mysteries?

 

23 hours ago, John said:

Thomas Back's passing was a sad loss to astronomy.

Sounds like he was a remarkable man, I read the link that Louis D sent. What a shame. One could argue perhaps that imitation is the highest form of flattery and his legend lives on in those designs, even if they were copied without permission. I read that the designs still technically belong to the family and were licensed by a particular vendor for a while but it doesn't seem like thats the case any more. 

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On 25/09/2020 at 13:31, Arneb said:

Whilst it has a focal length significantly longer than 40mm, the Tele Vue 55mm plossl would give a comparable TFOV to a 40mm /68 Deg eyepiece - albeit with a lower magnification.

Coming back to this - I know I get technically more coverage in the EP overall due to the extremely long FL but would I get that lovely "my god, it's full of stars" effect like you do with the very wide angle EPs? Whilst the GSO 30mm is not the world's best EP it does have a reasonably large FOV and I'm hoping to get even more of an eyeful! 

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Soooooo... sorry for the old thread bump but in the end (and after some encouragement from my partner) I just plumped for the Panoptic(!)
I'm upgrading my mount to an EQ6-R Pro (my first actually new mount, plus first goto) because my old tiny one doesn't cope with the 80ED well and want to future proof myself, so I thought if I'm buying a mount for life I should get the EP for life as well!

It's currently constant clouds here anyway so I'm just taking advantage of the situation :D

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4 hours ago, badhex said:

Soooooo... sorry for the old thread bump

Nothing to be sorry for at all.  You started the thread.  It's almost expected that you report on your final decision/outcome no matter how much later.

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1 hour ago, Louis D said:

Nothing to be sorry for at all.  You started the thread.  It's almost expected that you report on your final decision/outcome no matter how much later.

haha yeah, perhaps it just *felt* like I took forever to make a decision :D

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It arrived! Holy smokes it is huuuuuuge!

Now I just need to wait for the new mount to arrive so I can *actually* use it :D My current mount would almost certainly collapse under the weight!

 

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