Maximilian said:
Mikehit said:
AvTvM said:
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I fully expect them to move to shorter flange focal distance with mirrorless FF. Plus adapter for all EF glass.
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Canon have immense experience in designing teleconverters, and still teleconverters take a hit on AF speed and accuracy ...
Hi Mikehit!
Sorry, but I don't get your point.
A flange distance adapter is not a teleconverter.
A teleconverter has an influence on optical formula, focal length and aperture.
An adapter is only setting the optical formula in relationship to the image plane.
And it has to conduct the electrical signals properly - without altering them.
Problem with EOS M and adapter hitting the AF performance of EF/EF-S lenses is also not clear to me.
But that's a question for Canon development. It seems they've decided to built up the EOS M AF system different to the EOS.
So why should they do so again when aiming at customers with EF lenses?
I was confused about Mikehit's point and what he meant. It's not only "the glass in the converter", it's the distance that light have to travel. Even if the teleconverter is glass-free, AF would still take a hit!
Think of extension tubes which are about the size of a DSLR-to-Mirrorless adapter. They cut the light that reach the sensor (among other things), which makes AF harder for the camera. I do realize that this is not only due to loss of light, but also due to the shallower DoF, but stack a few extension tubes or use a macro bellow & your frame will look darker in the viewfinder, making even manual focus harder (that, and the DoF gets ridiculously shallow as well). Basically, you will lose a few stops of light with these tubes. It could be the same problem with mirrorless cameras using AF adapters.
A full-frame mirrorless using EF mount lenses with the typical EOS focal flange distance is nothing to write home about. It's basically a permanently locked-up mirror Canon DSLR with EVF.
I don't think it is easy or even possible to do EF mount with shorter FFD. But who knows what magical tricks they might have? I believe that would require some glass element like the Speedbooster adapters, and I wouldn't be amazed if we gain a stop or two. The EF mount is larger in diameter than other 35mm format cameras, so it'd be interesting to see what they would do.
On side note, sure Canon ditched the FD and move with a new mount with their EOS AF cameras. But I doubt they would invest into an another Mirrorless-only FF mount that goes parallel with their DSLR's EF mount. We all know how Canon fears cannibalizing their sales