Looking for an 'entry' level Telephoto lens for my Canon 450D. Looking at Sigma AF 70-300 f4-5.6 100 This is a DG Macro Canon fit
Tamron AF 70-300 f4-5.6 Di LD 120
CANON EF 75-300 f4 5.6 111 140.
I believe the USM models are more recent??? but more than I can afford. Would any of the the other 3 be compatable with my 450D? Thanks