I talked to them about the f/8 issue and the answer was the same. It's because the way they have the AF points.
I guess that for what you do, f/8 AF is important. Do you consider it an issue or not? Considering the 1Dx will be a great camera. Can it replace your 1DIV?
The AF is lightning fast and just locks! I probably had about 3 images out-of-focus during my overnight used of the camera.
I still believe using a full frame for bird photography is not ideal even using a long lens like my 800mm. I'll keep my 1D MKIV and 5D MKIII for landscapes.
can you explain to me why? is it because of the lack of the cropfactor? or the more shallow DOF?
wouldn't a 1D X with a 1.4 extender almost be the same as a 1D mk. IV? (like in autofocus speed, image quality etc.)
If you use a 600mm lens with a 1.4x TC attached to a 1D X, you’ll get 840mm at f/5.6 while with the same set up with the 1D MKIV is 1092mm at f/5.6 with an excellent AF performance.
You won’t be able to use a 600mm with a 2x TC anymore so that’s out of question. Same goes with the 500mm.
I truly don’t see a reason to sacrifice 252mm by using the 1D X.
In other words
600mm X 1.4= 840mm (1D X with a 1.4x TC – f/5.6)
600mm X 1.3= 780mm (1D MKIV – f/4) – No tele-converter attached.
600mm X 1.3 X 1.4= 1092mm (1D MKIV with a 1.4x TC – f/5.6)
600mm X 1.3 X 2= 1560mm (1D MKIV with a 2x TC – f/8) with a not so great AF. Single point.
800mm X 1.3 X 1.4= 1456mm (1D MKIV with a 1.4x TC – f/8) with a decent AF. Single point.
As you can see, a big difference.