|
Mmm... still doesn't make much sense... sky background detracts from all extended objects and the effect is pronounced in all fast scopes - in that respect we should all be using scopes round f/10 or slower to so that we have a maximally dark background in the eyepiece.
All the dobs at f/5 or faster will be equally disappointing in anything less than a very dark site...
... so why are the vendors all pushing f/4 to f/5 Newtonians, when they're a fairly poor choice in urban skies ?
Hmmm..
|