400mm the sports shooter choice

this is the big white lens you see on the sidelines of the NFL and other sporting events. Now I dont do sports very often but I do nature photography.
Witha 2.8 apeture it is tack sharp even in low light. If you have never veiwed a 2.8 lens on your camera you are in for a treat as it allows so much more light in and the viewfinder is so much brighter you can see.
The amazing image stabiliazation is incredible less blury shots in low light or due to camera shake. The image stabilization actually has gyros that stabilize the image from shaking in the viewfinder amazing huh. Canon was the first to do this in a film camera lens. Nikon is playing catch up now.
this lens usually comes with cusotm carrying case that is built like a tank and a hood for the front element.
I recommend before buying this lens you view one in person. this is no light duty lens Probably one of the largest lenses on the market at around 18 lbs you need to go to the gym to carry this around long.
And reconsider getting a heavier tripod and a wimberly tripod head just to be able to hold and handle this huge monster.
that said I carry it in a special backpack designed for the lens or sometimes ai carry it over my shoulder attached to the tripod in the back country. It will wear you down fast. I KNOW.
Because it is a 2.8 it is extreamly fast this is also good beacuse I bought it for the reason of three lenses in one really
a 400mm 2.8 with a 1.4 x teleconverter is 640mm f 4 this is still a fast lens
400mm 2.8 with 2x teleconverter is 800mm f5.6 wow still fast
400mm with both new 1.4 and 2x series II teleconverts stacked is a 1160 mm f8 lens still amazingly fast.
I can get crystal clear images that are still tack sharp with both stacked teleconvers that is somethign alot of lenses cant handle. That is why I say this is a 3 lens in one and much more affordable then buying a 400 500 and 600 mm lenses.
buy one get three.