Revelation 50mm Eyepiece 2"

[Astrodread]

Hi

Does any one know how good Revelation 50mm Eyepiece 2" are with 10" Newtonians?

Revelation 50mm Eyepiece 2"

Many thanks

Astrodread:)

[enigma]

I never tried the specific eyepiece, but I think in a fast Newtonian this will produce an oversized exit pupil that could be a a waste of light. In this regard the Revelation 30mm 2" might be a better choice, but since it is much wider (70 degrees) it could also show more distortions near the edge of the field of view. Maybe someone with real experience with both eyepieces could throw some light on this?

[Astrodread]

Thanks Enigma for your response. I will look in to that 30mm. Ive got a 28mm 2" Skywatcher LER which is ok and will do for now. I just need to get as low as magnification as i can for some nice star fields and for objects like M31.

[Chris H]

What focul length is your 10" dob? With my mass produced Orion 10", focul length 1200mm, I use a Skywatcher Nirvana 28mm. With its 82 degree field of view I get a 2 degree TFOV which is nearly the max for my scope. I could go a little bigger with the Nagler 31T5 but I feel the gain is not justified by the cost involved. Above this the exit pupil gets too big. For wider fields of view I think you would need to be looking at getting a refractor, M31 for example is nearly 4 degrees accross.

[Moonshane]

I agree with the comments above. never used one but suspect that a 50mm eyepiece would only be good with an SCT or similar.

I have a 35mm Panoptic which I use in my dob and this is about the limit at f5 in terms of exit pupil for me at just under 7mm. with a 68 degree field this gives about the same field as the 28mm Chris mentions but in my 1600mm scope it gives about 1.5 degrees.

[Astrodread]

Thanks Chris and Moonshane. My Dob is a f5. big isnt necessarily better in the Eyepiece world im guessing. Ive checked out quite a few large fov eyepieces and to my shame ive dribbled over the thought of Naggler but thats not possible for me. Budget is tight sadly. Ive seen Adler Optik SWA 70 Degrees 26mm,32mm and 38mm on Scope and skies Has any one got these??

[russ]

The Adler Optik series are extremely good for the money. They won't be perfect in an F5 scope but no 2" eyepiece below £150 will be. I had the 26mm and 32mm, loved them both. Lovely big field, sharp across 70%. Really tight stars in the sharp part and the outer didn't bother too much.

No experience of the Revelation series but i'm sure they are as good as the Adlers.

[Astrodread]

Thanks Russ. I see you've got the TMB clone 8mm. I tried out my new 2.5mm, 4mm clone and and 6mm Planetary 2 on Jupiter last night. Amazing. Cant believe i was using a second hand cracked lens 4 mm meade pl for so long These TMB clones and the TMB are amazing.

[russ]

Yeah i'm mighty impressed with my TMB Clone. It's sharp, well corrected and good light throughput. Only downside is some blacking out if the eye isn't positioned in the sweet spot.

Have you seen the Revelation 2" eyepieces are all on offer at the moment? Choose any from the range for £35 each. That's a real bargain as they sell for £30-35 secondhand.

[michael.h.f.wilkinson]

Regarding exit pupil: the largest sensible focal length of an EP is simply 8 x the f-ratio if you are you, 5x the f-ratio if you are older than say 35-40 (so older guys have an extra excuse for UWA EPs ). Given the excellent quality of the TMB Paragon 40mm I have, I would check out the 30mm Paragon which is supposed to be every bit as good, and easily comparable with a Panoptic according to some.