[Wavytone]

Low magnification isn't the issue on short f/ratio newtonians.

I'd be interested to know:

1. What is your lowest magnification, ie determined by a 6mm exit pupil (or thereabouts) vs your highest magnification. My guess is your range lowest:highest isn't much more than 1:4 or 1:5.

2. how you're achieving high powers eg magnifications above x1 per mm of aperture. This is more relevant to smaller apertures - trying to use a 60cm f/3.5 scope at 700X obviously isn't sensible. But using 400X on a 30cm f/3.5 has some point, in excellent seeing. And please don't tell me a Barlow...

3. On large apertures the seeing limits the useful magnification to such an extent that I suspect those with apertures of say 60cm never get past lower magnifications on most nights, simply because the seeing is too turbulent, unless you are lucky enough to have a superlative location.

Hence I'd expect most of you don't use much more than 0.3X or 0.5X per mm of aperture.

Mark, I appreciate the temptations of short f/ratios with respect to the implications for tube length, weight, portability, and mounts - but they're less than ideal optically IMHO.