The main difference between the two is the diopters. The MSN-202 focuses nearer to the subject (2-3 cm if i remember correctly) and provides a even higer level of magnification. Works best on a prosumer camera than on a DSLR. For most people, the DCR-250 should be sufficient to work with. Its terribly hard to focus on your subject when using the MSN-202 on a DSLR, you'll need to be very precise with the distance between subject and lens. Hope this helps