DxO sitesinde de aşağıdaki gibi bir karşılaştırma yapmak mümkün:

Canon EF 300mm f/2.8L IS II vs. Sigma 120-300mm f/2.8 DG OS Sport vs. Canon EF 300mm f/4L IS

http://www.dxomark.com/Lenses/Compare/Side-by-side/Canon-EF-300mm-F28L-IS-II-USM-on-Canon-EOS-5D-Mark-III-versus-Sigma-120-300mm-F28-DG-OS-HSM-S-Canon-on-Canon-EOS-5D-Mark-III-versus-EF300mmf-4L-IS-USM-on-Canon-EOS-5D-Mark-III__400_795_1063_795_263_795