When the 200-400 lens becomes available I will be purchasing it or the 400 2.8 prime. The delima of which of these 2 lenses would be more effective is making me mad.
The versatility of the 200-400 with the built in ext will be excellent. To think, though, that with the 1.4X and 2X ext gives you 3 incredibly useful focal lengths is equally incredible.
Owning the 70-200 f/2.8 II and using both ext's on it often, I think that the 200 to 280mm range of the 200-400 would go unused much of the time.
I have owed the 600 f/4 300 f/2.8 and the 200 f/2. Of all of those lenses, the 300 f/2.8 was my favorite.
Has anyone else given this much thought?
The 200-400 f/4L zoom lens cannot REPLACE the 300 2.8 and 400 2.8 primes. For most sports shooters, f/4 isn't going to cut it and I've experienced this myself, especially night football where all you have are stadium lights. You also need access to all of the AF sensors in the 1DX and/or 1D Mark IV. All other purposes, yes, it's a great lens and would alleviate the need to buy a 300 and 400 prime perhaps.
Although in theory I agree, it provides useful versatility. I am just back from shooting a waterpolo match, and although the 400 f/2.8 on a 1DX performed like a beaut, not having the second body with the 70-200 or the fisheye made me lose quite a number of shots (second body is being serviced). Just saying, 200-400 is useful versatility wise.