Chrissyo,


That would give 138x in your 10" f/5 (divide the focal length of your scope with the size of your mirror will give you the f ratio)probably need to use a barlow with that ep for mars at the moment. I use either a either a U/O HD 12mm or a Pentax 10mm XW with a x2 or a x3 barlow for planetary observing. A 7mm to 4 or 5mm ep would give you similar results

regards