sigma 17-70 why f4 or f4.5 max on my canon 350D

mantras siva posted a new topic:

Hi

maybe i'm a fool

but yesterday i tried the sigma 17-70 f2.8 4.5 on my 350D



well i take some shoots and i did notice that almost everytime , the lens uses a aperture of f4 in P mode



is normal?





never cross the aperture about f4 , i was used to shoot @ f11



is normal , or my lens did not work on my 350D?



thanks

have a nice day