reeloptions wrote:I am concerned about the weight of the canon 400 2.8 is vs the lighter alternative of the 300 2.8 is.With a 1.4 extension and using a 7d camera-do you get enough benefit from the 400 to justify hauling it around.Use the lens for shooting birds and other wildlife.
I don't have either of these lenses, but the question would be how often do you shoot at 400 vs. 300? While the 300 takes a tc as well as any lens in Canon's lineup, it would not be as sharp as the 400. If weight is the primary issue and you don't mind losing some sharpness by using a TC, have you considered the 400 f/5.6 or the 100-400? While neither is in the class of the 300 or 400 f/2.8 lenses, they are still very sharp and weigh considerably less. There is also the 500 to consider which weighs considerably less than the 400 f/2.8 and would extend your range without the use of a tc (although the 500 also takes tc's very well). If birds are your primary targets, I think the 500 would be a better choice than either the 400 or 300. I know of a gentleman who shoots birds almost exclusively and his lens of choice is the 500 with a 1.4x tc. This combination puts him at 700mm and he also shoots with a crop sensor camera which effectively puts him over 1000mm and his images are spectacular.