Quote Originally Posted by Richard Lane
Do you now have to send it in for the firmware update?

If you do, do you now have to pay for shipping and insurance, that could get a little expensive?
Mine is one of the lenses without the new firmware, but being such a minor upgrade I'm in no hurry to do it. Besides, the 1DX has an option for upgrading lens firmware, so I'm hoping that I'll be able to update the lens myself sometime in the future. If I do have to send it in, I have the lens insured anyway, so at least I'd only have to pay shipping to Canon (which I might be able to talk Canon into paying for as well, CPS can be cool like that).

Quote Originally Posted by Richard Lane
I think the 200-400mmf/4 +1.4X would be a great addition to your 600mmII. That zoom focal range will cover a lot of photo op's, and now with the new low ISO performance of the 5DIII and 1DX, it makes this lens even better. The 600mm is definitely too big for travel and I feel that I would probably end up leaving it home.
I also was thinking that the aperture on the 200-400/4 1.4x would not be such a big deal with the ISO capability on the 1D X. I don't think f/4 vs. f/5.6 @ 500mm is such a deal breaker anymore. But if I'd end up using it with the 1.4x in place most of the time, then the 500mm probably would make more sense... I dunno, I'm still undecided. I also have a 7D, but I don't want to make my lens focal length decisions based on anything other than a full-frame camera (John, I'd recommend you do the same). Going forward, I don't know what Canon's plans are for cropped-sensor cameras. There may not be a 7DII, and even if there is, it won't be as full-featured as the 1D X. One of your previous posts talked about how you felt a 500mm was too long at times on the 1D4 at Yellowstone. Was it way, way to long, or do you think it would have been perfect on a full-frame camera for Yellowstone?

Quote Originally Posted by Richard Lane
If someone thinks they need 500mm most of the time then they will be able to use 41 cross-type points, but with the 1.4X, that number will drop to 21, or essentially in half to Group E.

The 600mm f/4 will maintain the 41 cross-type points, Group C.

Naturally, the bare 70-200mm f/2.8L IS, 300mm f/2.8L IS and 400mm f/2.8L IS will also benefit from the dual cross-type points or Group A.

Incidentally, I thought it was interesting that the new 24-70mm f/2.8L II is group A, while the older 24-70mm f/2.8L was in Group B.

Other notable differences were that the 800mm f/5.6 can use 21 cross-type points, but it can only choose between 47 points, whereas the 600mm + 1.4X @ 840mm can also use 21 cross-type points, however all 61 AF points are available for selection.
Yeah, I think it's really unusual that the 800/5.6 can only choose from 47 points while the 600/4+1.4x can still choose from all 61 points. I'd love to know what design limitation is causing this, being the nerd that I am.

John, have you made any decisions yet on your 500/4 vs 600/4 dilemma?