What's the difference on the Sigma EX DC vs. the Sigma EX DG?

Anyone know what those letters are even for? Better build quality?

DC is designed for a cropped sensor.

DG is designed for a full frame sensor.

ahh crap so does that mean I should get rid of my Sigmalux? I don't plan to upgrade my body. lol <<

No, my first reply may have been misleading. DG is designed for a full frame but the sigmalux will also fit on the XSI.
DG will fit all current DSLR's as well. As for FOV, you can do some research on that here..

so not to confuse you basically a DG is like EF

and a DC is like EF-S

Leonid Photography wrote in post #11095237
so not to confuse you basically a DG is like EF

and a DC is like EF-S

what he said

Here's alink to the Sigma page ,

http://www.sigma-photo.co.jp/english/le​ns/index.htm

Leonid Photography wrote in post #11095237
so not to confuse you basically a DG is like EF

and a DC is like EF-S

Yep

DG just refers to some special coatings on the glass because digital sensors are reflective, film is not, Theoretically this means that you could end up with some funky reflections without them...

And the 50 is a great lens on a crop for a lot of things