Wat are the difference between the old Sigma 70-300mm F4-5.6 APO Super (Gold Ring)
&
the new Sigma 70-300mm F4-5.6 APO Super II (Red Ring)?
Faster focus? More silent mechanism?
&
the new Sigma 70-300mm F4-5.6 APO Super II (Red Ring)?
Faster focus? More silent mechanism?