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Minimum quality 82degree+ eyepiece for f/4.9 newtonian?


drbones

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I was wondering what people's experiences are with using the wider angle eyepieces with a fairly fast Newtonian and what they'd recommend?

Currently looking to upgrade to a couple of very wide angle eyepieces to help with viewing DSOs and to make manually following objects like the smaller planets with our 10" dob a bit smoother compared to the current 7mm plossl we're using.

As I understand it, the more budget 82 degree eyepieces will struggle vs a higher quality, lower FOV eyepiece due to the faster scope, but I was curious as to what the "minimum" (for lack of a better word) I should be looking at for an 82/100 degree eyepiece should be? I'm in the UK so any eyepieces available in the UK/Europe should be fine.

Some of the series I was looking at would be SW Myriad, the ES 82/100 degree series, Meade series 5000 UWA and there also seems to be a series of 100-degree eyepieces that get sold under a few different brands, one of which is the TS XWA series. Looking at both a ~20-28mm and ~5-9mm EP to pair with a 2x barlow for a good range of magnification, and will probably be purchasing a coma corrector at some point.

Are there any of these I should be looking at avoiding in particular? A small amount of aberration at the edges isn't really a huge issue as I'm not expecting perfectly sharp images across the whole field, just wanted to avoid the worst offenders on fast scopes so I know what to avoid and what to keep an eye out for second hand as well.

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First, welcome, drbones, since this is your first post.

I have an f/5 newtonian and these widefield eyepieces: Myriad 110° 5mm and 3.5mm, Panorama 82° 7mm, Maxvision (Meade) 82° 18mm, TS 82° 4mm, Explore 82° 4.7mm, Meade 82° 24mm. They all perform great with negligible differences at the very edge. The 4mm TS has a tiny bit more lateral color than its Explore 4.7mm counterpart, but costs less, so value is the same (and great!).

Other differences, the amount of crescent effect, or the tiny loss of sharpness near the diaphragm are so minute, I don't bother with them when observing. I looked for them when testing the new gear, but now completely ignore them in real observing time. All of them keep double stars split at the extreme limit of the field, and Airy disks remain tight and round. Lunar craters beraly lose detail in the same test (there is also some slight  change of performance between night and day, but it appears to vanish when my eyes get used to the new items).

Seems that all these optics which are derived from Tele Vue ideas work great, no matter what the interpretation by competitors is.

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For a fast scope consider Meade series 5K UWA, ES 82° or William Optics UWAN and its re-branded identical twins.

I have a 16mm Skywatcher Nirvana (one of the WO UWAN clones) which performs excellently in my f/5 refractor.

The Meade 5K UWA get a good press over at Cloudy Nights.

Personally I don't like ES 82°. I bought an 11mm ES 82° which had an eye relief that was uncomfortably short. The stated eye relief would have been long enough, but in practice it fell short. I returned it for that reason: my eyelashes touched the glass if I wanted to see the field stop and I would've had to clean it after every use. Optically very sharp and well suited for f/5. The field stop was unsharp, btw, but that didn't bother me much.

Celestron's 82° offering seems better for f/10 and slower.

Bye. Good luck choosing.

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Any 82/100* eyepiece will be fine at f/5 unless you're super critical? in which case get the ES which are great at f/5 or the Televue's that work down to f/4!

One of my favorite 82* EP's is the Celestron Luminos. these have relatively good eye relief unlike many other 82* EP's, and the 7mm & 15mm are great for just £95 a pop.   

https://www.firstlightoptics.com/celestron-eyepieces/celestron-luminos-eyepieces.html

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1 minute ago, Paul73 said:

I've never looked through a Luminos. But, at that price, it is tempting......

Paul

The only downside I noted was some reflections when viewing close to the Moon and not the best range of focal lengths. Great build, eye relief, and sharpness apart from that. I found the 7mm to be a great wide field planetary EP in particular, that one was my favorite I'd like another.

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14 hours ago, Ben the Ignorant said:

First, welcome, drbones, since this is your first post.

I have an f/5 newtonian and these widefield eyepieces: Myriad 110° 5mm and 3.5mm, Panorama 82° 7mm, Maxvision (Meade) 82° 18mm, TS 82° 4mm, Explore 82° 4.7mm, Meade 82° 24mm. They all perform great with negligible differences at the very edge. The 4mm TS has a tiny bit more lateral color than its Explore 4.7mm counterpart, but costs less, so value is the same (and great!).

Other differences, the amount of crescent effect, or the tiny loss of sharpness near the diaphragm are so minute, I don't bother with them when observing. I looked for them when testing the new gear, but now completely ignore them in real observing time. All of them keep double stars split at the extreme limit of the field, and Airy disks remain tight and round. Lunar craters beraly lose detail in the same test (there is also some slight  change of performance between night and day, but it appears to vanish when my eyes get used to the new items).

Seems that all these optics which are derived from Tele Vue ideas work great, no matter what the interpretation by competitors is.

Thank you very much! And as well to everyone else for all the replies - I don't have much of a chance to test various EPs prior to buying so given the money I wanted to be sure there wasn't any lemons on the faster end to completely avoid.

I think I'd almost hoped there'd be only one series to choose from to save me some effort ;)

That also reminds me I need to do a proper introduction post!

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11 hours ago, Lockie said:

Any 82/100* eyepiece will be fine at f/5 unless you're super critical? in which case get the ES which are great at f/5 or the Televue's that work down to f/4!

One of my favorite 82* EP's is the Celestron Luminos. these have relatively good eye relief unlike many other 82* EP's, and the 7mm & 15mm are great for just £95 a pop.   

https://www.firstlightoptics.com/celestron-eyepieces/celestron-luminos-eyepieces.html

These look pretty interesting, the 15mm and 7mm are tempting me although the 23mm does seem to be a bit on the hand grenade side of things

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The Luminos series is optimized for Celestron's own line of Schmidt-Cassegrain Edge telescopes, f/10 with a certain very small amount of field curvature. They don't have excellent sharpness near the diaphragm with faster optics, which is a shame because the Luminos have always been quite affordable. There was a very complete comparative test in Ciel&Espace displaying (with pictures of target charts) the edge resolution of various widefield eyepieces, the Luminos was the worst among a dozen. 

The test is no longer online, but Teleskop Service warns buyers that the Luminos line is not for faster optics, but optimized for Celestron's Edge series, or other flat-field intruments.

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Many observe DSO with 100 deg eyepieces with VG results and many also view the planets with 70 deg eyepieces with excellent performance. I use a Lunt 20mm HDC 100 ( Myriad) that works extremely well for DSO and think that a Pentax XW for lunar/planetary would be super.

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8 hours ago, Ben the Ignorant said:

The Luminos series is optimized for Celestron's own line of Schmidt-Cassegrain Edge telescopes, f/10

Don't the Luminos pre-date the Edge HD's launch? Also the Luminos are just the replacement for the Axioms, so not sure about them being optimised for the Edge scopes?

 My Luminos were sharp at f/7 and I have a soft spot for them at least :)   

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Not sure, I have not tried the Luminos myself, and I don't know if there are two generations of them. But the Ciel&Espace comparo did show a bit less edge resolution in the Luminos eyepiece, and Teleskop Service does advise people that they are preferably meant for flat-field instruments, and would not perform quite as good in scopes with field curvature. The advice is in the german description of the eyepiece, not in its english version.

But no modern eyepiece is disappointing, and some reviewers (like myself) become so experienced in seeking imperfections, they tend to see them much bigger than they really are. When I observe for enjoyment instead of hardcore testing, the differences are negligible, really. I remember a friend saying that such and such imperfection in a scope was "enormous", then I realized I had myself become too sensitive to these.

He's an imager who does not tolerate other than perfectly round stars up to the corners, and I'm a visualist who trained hard to interpret the minutest features in star tests (with success after much training), so we both forgot to take the long view (pun intended), and just observe the celestial stuff instead of judging optics harshly all the time.

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