Canon EF 400mm f/5.6L USM Super Telephoto Lens

[Mikeminnich]

anyone every use this lens? If so, how do you like it and also, I've read that it doesn't work with an extender..how true is that? Is the just the autofocus that doesn't work or the lens itself?

 

[rufus5150]

AF won't work except on the 1-series bodies and only with the 1.4x extender and only the center AF point. All other bodies will cease to AF and so will the 1 series with the 2x extender.

I've never personally used one (I use a 300mm F4 with a 1.4x extender which retains full AF plus has image stabilization) but a buddy of mine loves his 400mm. It's nice and light for the reach and the sharpness.

 

[Big Mike]

Yes, the problem with the teleconverters is that most cameras require a max aperture of F5.6 for AF to work. A TC will steal light, and thus if you add a TC, you no longer have F5.6 and thus AF may not work.

If you use an off-brand TC, the camera might not realize there is a TC and thus may not actually disable anything...but the AF still may not have enough light to focus....but you could still focus manually, if you can see well enough.