Sigma APO 50-150mm F2.8 Lenses

Hi!

Sigma apparently came out with a new 50-150 mm lens (Sigma APO 50-150mm F2.8 EX DC OS HSM for Canon EOS DSLR) sometime in 2012 and it is getting very good reviews for fast and accurate focusing. I have a Sigma 50-150 mm lens that I purchased about 2.5 years ago and hasn't always produced the sharpest photos. First, is mine indeed an older version or are is there only one version? If they are different versions, can anyone recommend whether I should purchase the later version for better sharpness?

My lens has the designation Sigma APO 50-150mm F2.8 EX DC OS HSM but not the OS designation. I shoot sports mostly - indoor volleyball and outdoor track, with an EOS 50D, uing the "Sports" mode.

Thanks for any feedback and comments you can provide.

Jim

Yes, there are two version of the Sigma 50-150: http://www.fredmiranda​.com/forum/topic/63930​0

There is also a newer (and larger) version with Optical Stabilization.

If yours doesn't say "II" on it, you have the original version.