To put on the front of my 30D Ive been looking at the expensive 100-400L or the cheaper sigma 50-500 - but I have recently seen the sigma 80-400mm f/4.5-5.6 EX DG OS at around the same cost as the 50-500
Has anyone any experience of the latter as I have not heard much about it?
[SIZE=2][SIZE=2]Is it worth sacrificing OS/IS for an extra 100mm zoom or
would the 100-400L blow both the sigmas away?
[SIZE=2]Also what is the difference between the DG version of the 50-500 and the non DG? - I understand it was optimised for digital - but what does this mean and will it make any difference to the pics I take?