Finally on the TV firm

[Stu]

Thanks again chap

Will read later

Stu

[Moonshane]

There are of course two differenbt considerations for exit pupil. 1) is it too big for your pupil? I think in this case, the light is more spread over a wider area of the eye. if the EP is too big then I think we all agree that we are wasting light/aperture but that in some cases this is not an issue especially at dark skies. e.g. I'd say a 31mm T5 Nagler is too much for my f4 scope (effectively f4.5 with the Paracorr), but at PSP I used Stu's for a little while and the view was still superb vs my usual 26mm Nagler. It was actually quite a different 'feel' and the field was not actually as different as I expected.

and 2) is the exit pupil small enough to make the most of the object I am observing? this relates to getting an 'ideal' exit pupil for brighter objects or those where more definition is needed as in planets and doubles/lunar. this is where you can play a little with the magnification/exit pupil to get the one that hits the mark.