2" eyepeice

[Astro_Baby]

I always worry about wasting light - its a constant source of concern to me because I wonder what kind of bill I might be running up

[Ags]

From my understanding [or not ;-)] of the optics I think a large exit pupil shows itself as a dimming accross the whole field. Imagine a refractor made with an eyepiece with a focal length identical to the objective lens -in that case the exit pupil is the same as the aperture. Stars viewed through the scope would be just as bright as if no scope was used! I've used a refractor as an example to keep the secondary shadow out of it - which is a separate issue I think, it just also happens to pop up at low mags.

I think each point of light in the field of view exits the eyepiece as a little collimated column of rays - the diameter of that column is the 'exit pupil'.

[russ]

That 24" meade is seriously tempting me!!!

Just because it is the max FoV from a 1.25" format. I know that will come in useful one day.

You won't be disappointed, the 20mm is very nice too.

[Space Beagle]

I've just sent off for the Meade 5000 SWA 34mm..., well it's a really good offer is it not!!?!

So my SkyWatcher 32mm Panaview and Aero 40mm are going to have to find new homes..!!

Ooo! The 32mm PanaView seems to have gone already, blimey!!

I'll let you know how I get on with the Meade..!!

Doc

[dph1nm]

I've always wondered about this too - what actually does happen if there is a mismatch with the eye and exit pupil?

It is equivalent to stopping down your scope, as the exit pupil is essentially an image of the primary mirror (or lens in a refractor).

NigelM