I'm deciding on a 32mm or 26mm eyepiece. One gives me an exit pupil of 5.5mm, the bigger one an exit pupil of 6.8. Do you think I'd be wasting light with the 6.8mm exit pupil, since I'm 63 years old?
Exit pupil
Started by Racmaster1, 10/19/2005 12:55AM
Posted 10/19/2005 12:55AM
Opening Post
Posted 10/19/2005 01:05AM
| Edited 10/19/2005 01:05AM
#1
Do you observe from a dark sky site? Do your pupils dilate to 6.8mm?
If the answer to either of those is "no" then I'd go with the smaller exit pupil. You'll be less prone to seeing defects in your own eye with the smaller exit pupil as well.
If the answer to either of those is "no" then I'd go with the smaller exit pupil. You'll be less prone to seeing defects in your own eye with the smaller exit pupil as well.
Regards,
Louis Marchesi
[COLOR="Gray"]New London Township, PA[/COLOR]
Posted 10/19/2005 04:24PM
#3
Lou:
It is likely that you would be "wasting light" with the 32mm eyepiece but wasting field of view with the 26mm.
The 26mm is not going to be any brighter than 32, just a larger image.
Since the 32mm will be your widest field of view, I think it makes sense to waste/under-utilize a bit of light/aperture and get the larger field of view.
jon
It is likely that you would be "wasting light" with the 32mm eyepiece but wasting field of view with the 26mm.
The 26mm is not going to be any brighter than 32, just a larger image.
Since the 32mm will be your widest field of view, I think it makes sense to waste/under-utilize a bit of light/aperture and get the larger field of view.
jon
Funding Member
