I realize that you get one heck of a lot of reach with the Sigma 150-500mm lens, but would you really want to buy a lens with a minimum of 5.0 aperture? I keep thinking that I want to get lenses that are a constant 2.8, or maybe I could be convinced to get a long lens with something like a constant 4 or so, but 5.0 to 6.3? This lens is reviewed by Pop Photo, if you can call a one page a review. There is not a single negative thing about this lens aparently, and no mention of the aperture restriction. They also tell you that it is compatable with their teleconverters without mentioning that it would further limit the light entering this lens. Not really sure why someone would buy this lens, even less why someone would trust a “review”¬† by Pop Photo.