300mm f/4 L IS with 1.4 extender or 400mm f/5.6 L

[powers_brent]

Basically just as the subject states. Which woud you say is better? 300mm f/4 L IS with 1.4 extender or 400mm f/5.6 L? I have read Bryan's great reviews, but was wondering what input anybody else may have. Purpose would be wildlife and birding on a 1.6 crop.

[Sinh Nhut Nguyen]

short answer: the 400 f/5.6L is better than the 300 f/4L IS + 1.4 combo in term of sharpness and focusing speed.





The 300 f/4L IS + 1.4x combo is more versatile.

[Jon Ruyle]

It just depends on which focal length you use more and now important the IS is. There is no way the IQ of the 300 f/4 + extender can compare to the 400 f/4.6, see for yourself.


On the other hand, I agree with Nate: 300mm + extender is more versatile, both because of IS and because you can also shoot at 300mm (400+ extender is possible but a very slow f/8 and you lose af).

[wickerprints]

Never underestimate the power of IS.