I compared a $200 telescope to a $800 one and the cheap one won for deep sky

Borrowed my buddy's fancy Celestron for a weekend to compare with my old Orion SkyScanner. Spent three hours at a dark spot near Lake Whitney last Saturday. His scope had all the bells and whistles but the views of Andromeda were honestly muddy and dim. My little tabletop reflector gave way sharper results on the same target even though it cost a quarter of the price. I think the issue was his aperture was too big for the light pollution we had that night even though we were in a rural area. The cheap one just grabbed contrast better with its smaller mirror. Has anyone else found that smaller scopes beat big ones under not perfect skies?

2 comments

2 Comments

brian_kelly9125d ago

Your buddy's scope probably had too much aperture for the conditions, plain and simple. Big mirrors collect more light pollution just like they collect more starlight, so under anything less than perfect dark skies they can wash out the contrast. A smaller reflector like your Orion will always beat a bigger one when the sky isn't cooperating because it's more forgiving of background glow. I've seen the same thing happen with a 6 inch Dob against a 12 inch on a hazy night near town. Also check if his Celestron was properly collimated, those mass produced scopes sometimes come from the factory a bit out of whack and that kills contrast on deep sky targets. Some people think bigger is automatically better, but for visual astronomy under real world conditions a well collimated small scope often wins out.

aaronrobinson24d ago

I read somewhere that even the pros use smaller scopes for planetary detail because big ones just amplify atmospheric blur.