Review on Opteka Definition Telephoto Mirror Cameras by Brandon Grzankowski

The secondary mirror is not a corrector like Maksutov's Cassegrain or Schmidt's Cassegrain. This is a reflective surface. I would guess that the reason for this is to cut costs. The idea is to fool people with what looks like a quality product but is actually poor optical design. The mirrors are probably uncoated and this makes the picture darker than you think. The secondary side is quite large for this lens, which is reflected in the lack of contrast. At night it fails the most and that was my biggest disappointment, the moon was good or bad and that's the best I can say about the lens I got. Daytime shots are ok, nothing special, a decent bridge camera can do better. I do not recommend this item. Save your money and choose something better.