Originally posted by legacyb4 I think *that* petal hood won't do you much good on a cropped sensor: it's pretty obviously designed for a wider-angle lens. In general, I'd say that the petal hoods are mostly only best when they're specifically-designed for your lens, or if your lens is a really-wide-angle that would otherwise take a very short hood.
I prefer round or square/rectangular hoods that'll let you stand the lens on them, in general: there's less hassle about handling them.
These lenses don't seem to be fussy about vignetting, ...since you have that 50 coming, you could always try getting one with a lot of coverage, and if it chances to be *too* long or tight for the 28, you can shift it up to the 50.