I also forgot to mention that i have a f/6.3 telecompressor from meade that takes my telescope down from f/10,for visual and photographic use for deep sky stuff,nebulas,galaxies,meade also makes a f/3.3 compressor for photography only not visual.the fastest mirror in a telescope that i ever heard of visual is f/4.0,anything below that for visual use would suffer from coma and aberrations no matter how well you collimnated your mirror.Rule of thumb,faster f ratios for deep sky stuff to brighten them up,slower f ratios for planets,moon,sun photos to brighten them down to bring out more detail photographically and visually.Also aligning,combining and stacking of images is critical,i have seen people who have taken at least 2000 images of saturn,combining them into one,simnply out of this world images.