If you could find a UV filter with the right thread size I'm fairly sure there would be no problem with that. But, any sunlight incident on the filter, multi coating notwithstanding, is going to have more of a bad effect on contrast and flare in the scope than having the front element well recessed behind the end of the scope tube, as most scope tubes are, and even then this can be enhanced with a sunshade, effectively a lens hood. Though by all accounts decent quality lens multi coating is so good these days that you don't get a lot of flare even without a lens hood.
It's the Indian not the Arrow
Last edited by Ceathreamhnan; 24th October 2015 at 06:14 PM.