So as far as using an extender, how far would you dare to go? I've used a 1.4x extender ii (canon) with my sigma 150-600 and seem to get acceptable images. I've wondered about grabbing a 2x because I can't seem to get close enough. Would that be asking too much?
I'm sure it dim up to f/11 with the 2x... What if I stacked them? I think that'd push it to just past 1600mm... What f/16? Too much? Just buy a blasted telescope? I know I wouldn't be able to hand hold such a set up.
Curious but not sure I want to drop 500 bucks on the extender to just test...
Hard tell with the 150-600. I have used it on my 100-400 II. I prefer it on my 400 prime. You can crop a lot too.
Maybe rent one first.










