I've read with interest the various threads about optimal exit pupils. There seems be a consensus, albeit with some variation/dissent, that a 2mm exit pupil is about ideal for much DSO observing.
Have an f/5.4 dob. Ended up with 12mm and 10mm eyepieces, which give me exit pupils of 2.2 and 1.85. In other words, straddling the "ideal".
In your experience, which will serve me better? Would you go higher or lower for your workhorse eyepiece?
How much depends on sky conditions? I preume that darker skies would tolerate the smaller e.p. better, but I'm under small city suburban, semi light polluted skies, perhaps mag 4.5 skies when transparent with Milky Way somewhat visible.
I also presume that one's eye make a difference... young eyes with bright pupils probably can go deeper, with smaller exit pupils, and see more with darker, more magnified views. Old geezers, which is more what I am, probably do better with larger exit pupils and less magnified and, therefore, brighter views.
I'll likely keep both, but as they are $ eyepieces, I may replace one of them with a less expensive eyepiece in the same f.l. or barlow another premo eyepiece to get to the f.l. of the one I'd sell.
The question arises from an observing session early this morning in which I was struck by how different the Ring Nebula appeared in 14mm, 12mm, and 10mm. I found it at 26mm, jumped to 10mm, was initially impressed by the view, but then the 12mm really knocked my socks off with a real glowing ring. The 14mm was a pale third, showing a smaller, less distinct object. (Of course, I discovered later this morning that the 14mm had some minor, left over condensation on it from a session a week ago. That may have dimmed the views.)
Any thoughts?
Have an f/5.4 dob. Ended up with 12mm and 10mm eyepieces, which give me exit pupils of 2.2 and 1.85. In other words, straddling the "ideal".
In your experience, which will serve me better? Would you go higher or lower for your workhorse eyepiece?
How much depends on sky conditions? I preume that darker skies would tolerate the smaller e.p. better, but I'm under small city suburban, semi light polluted skies, perhaps mag 4.5 skies when transparent with Milky Way somewhat visible.
I also presume that one's eye make a difference... young eyes with bright pupils probably can go deeper, with smaller exit pupils, and see more with darker, more magnified views. Old geezers, which is more what I am, probably do better with larger exit pupils and less magnified and, therefore, brighter views.
I'll likely keep both, but as they are $ eyepieces, I may replace one of them with a less expensive eyepiece in the same f.l. or barlow another premo eyepiece to get to the f.l. of the one I'd sell.
The question arises from an observing session early this morning in which I was struck by how different the Ring Nebula appeared in 14mm, 12mm, and 10mm. I found it at 26mm, jumped to 10mm, was initially impressed by the view, but then the 12mm really knocked my socks off with a real glowing ring. The 14mm was a pale third, showing a smaller, less distinct object. (Of course, I discovered later this morning that the 14mm had some minor, left over condensation on it from a session a week ago. That may have dimmed the views.)
Any thoughts?
