I am in the market for a new lens, up to now I have been using my EF 70-300mm IS for bird and nature photography. I am on a budget and would like to stay some where around the $2000 range. I have been reading and researching and have tentatively narrowed it down to 3 possible choices.
EF 100-400mm f/4-5.6L IS USM
EF 300mm f/4L IS USM + 1.4x EF Extender III
Ef 400mm f/5.6L USM
The criteria I most concerned about are
1 Image Quality
2 Image Quality
3 Speed of the lens
4 Autofocus Speed
Anyone who has any experience or opinions with these lenses or another lens I should be considering please post.