Your choice of diagonal depends on your photographic equipment. If you have a CCD camera, get the larger diagonal. But, if you’ll shoot with a large-megapixel digital SLR, a 1¼” diagonal will work.
Two-inch eyepieces have a larger field of view, but you have to weigh the cost. Your best bet might be to try several different eyepieces (owned by others) at star parties or astronomy club events once you’ve purchased your scope. — Michael E. Bakich, Senior Editor
Should I purchase a 1¼” or 2″ star diagonal for my new telescope?
Howard Foley, Springfield, Illinois