|
If you're interested in deep sky observing you'd find the 1.3 mm exit pupil the 13mm delivers a bit dim for general purpose deep sky viewing . A 17mm Ethos would be a little better ( 1.7mm pupil ). Personally I'd go for something like a 22mm Nagler which will give a wider field with brighter images and @F10 and Panoptic 35mm for wide fields..
I don't know whether those F6.3 telecompressors are usable visually but that needs to be looked into before you make your choice .
|