rprouty wrote:
Could the 5DIII be programmed thru firmware to focus at f/8 if Canon decided to let this happen?
Thanks
Technically, yes, all cameras can be programmed to perform autofocus function with f/8 lenses or slower. However, Canon just doesn't do that because the cameras would just poorly perform. With the exception of the 1D series, Canon DSLRs don't have a sensor that is designed to perform well when the widest aperture of a lens is f/8 or slower.
And yes, with many already developed Canon cross sensor modules (40D, 50D, 7D etc), Canon went to added time, expense and trouble to intentionally design a brand new AF sensor for the 6D that goes back to a single cross AF point. Canon will spare no expense to protect the 1D series.
rprouty wrote:
Could the 5DIII be programmed thru firmware to focus at f/8 if Canon decided to let this happen?
Thanks
I don't see why not.
I have used the Kenko 1.4X DGX on the Canon 400 f5.6 and it works well. All focus points are active. Most of the time the focusing speed seems the same as the bare 400 f5.6. Occasionally in more challenging focusing situations it will hunt a bit.
I have used the Kenko 1.4X DGX on the Canon 400 f5.6 and it works well. All focus points are active. Most of the time the focusing speed seems the same as the bare 400 f5.6. Occasionally in more challenging focusing situations it will hunt a bit.
I think you will find that, if you use point selection, it will only work well with some of the center points. At least, that was my experience.
I think it could and might well be updated to do so. The 5DIII is no longer the entry level FF camera and those who need a 1DX will still need a 1DX so I cant see a compelling reason no to. Add to that the fact that failing to update the 5DIII AF would be a clear admission that Canon is willing to cripple what is still a very expensive camera and I think we may well see f8 AF in the 5DIII. It would help the 5DIII compete against Nikon's offerings more than it would detract from sales of the 1DX IMO.
I have used the Kenko 1.4X DGX on the Canon 400 f5.6 and it works well. All focus points are active. Most of the time the focusing speed seems the same as the bare 400 f5.6. Occasionally in more challenging focusing situations it will hunt a bit.
If Canon cameras are programmed in such a way that it allows autofocus with any lenses, you can use 2x with 400L to make it an f/11 lens and use autofocus, but whether or not it performs well is another story.
I once used my 70-300L with Kenko 1.4x at 300mm, but it hunted quite a bit and the autofocus was not quite reliable.
RobDickinson wrote:
It uses the same af module as the 1dx so why shouldnt it be able to?
Canon may not want to but I suspect they will eventually.
I read that they are very close, but 100% the same. So, I'm not sure if 5DIII has a sensor that is sensitive at f/8.
They've restricted f/8 AF to the 1-series cameras up to this point, and there is no reason to think that they won't continue that marketing strategy in the future.
Why not? They did not plan to offer f/8 in a 1 body any longer. After D4 does and many customers where unhappy they decided it is better to give them back this feature.
There was no "1" AF system in any other body before, too. Why should they not decide to give it to the 5D III, too? It looks stupid to me to do not offer what 3rd party companies do and to expect worthy customers taping a pin.
