Have to return one!

[Camo 757]

I picked a Tamron 28-75mm 2.8 last week and love it. Tack sharp and great contrast. I was comparing a Sigma 24-70mm 2.8 Macro at the time and it lost out to the Tamron. I was at another Ritz Camera today and they just got another Sigma in. Of course I bought it. Took it home at it compared identically to the Tamron though it does focus slower and hunts a tad. I do like the look (82MM!) and robust feel more but the Tamron performs equally well, actually better if focusing is taken into consideration. Have a look at the pics below, both wide open at ISO 400. Tell me, should I keep the Sigma? I dpn't have identical settings to compare the lens for you but can tomorrow for a real side by side.

http://img.photobucket.com/albums/v729/mohassabo/_MG_6523.jpg

http://img.photobucket.com/albums/v729/mohassabo/_MG_6516.jpg

[Keiffer]

I don't know which one is which But I defintely like the first one. But than again could have been different lighting. But the first is clearer. So which is which?

[Camo 757]

oops my fault f4. Will post new comparible pics.

[eosnob]

Preferred 1st shot which has better lighting. But, the different lighting and composition makes it difficult to make a like-for-like comparison. Also, doesn't look like you nailed the focus onto the eye.

I would keep the Tamron 28-75. Why do you feel you need to replace it with a Sigma, if your copy is already tack sharp and great contrast?

[tim]

When it's this close the lens isn't really an issue. If you really want to compare them shoot a test chart like this one (http://www.canon-dslr.com/Canon_Jan05/Canon_SLR_Focus_Test.htm), on a tripod, with mirror lock up, and custom white ballance. It's much easier to tell on that than on random snapshots where multiple things change.

[grego]

You'll never really know when comparing two diff situations. Just get a still object from the same distance, same conditions, etc. etc.

That will give you the best chance at knowing.