Advice from 400mm f/2.8 and Canon 2x (III) users

[Nigel Cooke]

Howdy,

I've been using the 1.4x on my 400mm for a while and now am considering picking up the 2x extender for that extra reach. Opinion seems to be divided. I'm not overly concerned in regards to AF performance as much, but certainly am about PQ, or rather the loss of. Anyone out there shooting with the above combination (the lens is the first generation one) care to comment?

I see you can hire the extender which I may do depending on the feedback received here.

Thanks in advance,

Nigel

[Markus Jais]

Can't comment in the 2.8/400 but with my 4/600 the IQ with the 2x is great. I have made sharp images with 1/200 from a tripod. Artie uses that combo a lot with great success. That rig is new for me, bought it a few weeks ago but I am very happy. AF with 2x III and 1DX was very fast whenever I used it. Not yet tested for birds in flight.

Markus

[David Stephens]

The IQ of the EF 2.0X TC-III is great. It's far better to have actual pixels on the subject than to shoot at 400 or 560mm and crop.

[John Patrick]

I have the 400 f/2.8 IL Mk I and a 1.4x TC Mk I and 2.0x TC Mk II. I find the quality between the Mk I 1.4 and the Mk II 2.0 to be relatively close, with a slight edge to the 1.4. However, given the large improvement in the Mk III TCs, I think you'd be pleased with the IQ of the Mk III 2x TC on your 400.

John

[Blake Cook]

I'm not sure why but my 2x MkII is sharper than my 2x MkIII on my 600 f/4 MKII. Both end up with an MA of +3 on my 1Dx and I can't remember the settings on my 1D MkIV. Oddly the 1DIV 2xMkII, 600 combo is sharpest of all. Live view AF or MF does not change things.

Previously my 1DIV, 2x MkII and 300 f/2.8IS combo was unusable until Canon calibrate them as a unit. That combinations is now very sharp. Does it make sense to send the 2x MkIII alone to Canon for calibration or does it have to be the whole combination?