Janne Heimonen spotted something interesting in a recent Sigma presentation at Photokina by their CEO Kazuto Yamaki: a listing for a Sigma 300mm f2.8 EX DG OS HSM lens. Sigma currently has only a 300mm f/2.8 EX APO DG HSM lens in their lineup ($3,399). Here is the meaning of Sigma's lens abbreviations:
The entire video of the presentation: