[matt]

Thinking of buying a powermate but am not sure which magnification to go for?

Apart from the boost to magnification they offer for individual EPs (3x, 4x and 5x) and the need to keep magnifications to acceptable/ practicle limits are there any other factors to take into consideration which make one more preferable to another?

I'm wondering whether a scope's f ratio dictates which way you go?

What else would influence your decision?

Could I use all of them in my 8" f5 newt???

What about a Celestron C9.25?

Thanks