which one is sharper at the telephoto end , wide open at f/2.8?
I tried the tamron 28-75 and sigma 24-70 non HSM. And the tamron is obviously sharper at 75mm against 70mm of sigma. It seems to have a bit more contrast as well. But I prefer 24mm , isntead of 28mm at the wide end. Just wondering how is the sigma 24-70 hsm telephoto end at f/2.8, against tamron 28-75 @ 70mm?