Canon sensor for FF - will it require Phase Detect AF?

[AlanF]

The current Canon leading edge sensors for EOS-M mirrorless and liveview for DSLRs are based on Dual Pixel AF, which is widely applauded for its excellence for video and liveview. But, will DPAF be adequately fast for rapid focus? Do you think they will have to embed Phase Detect for action and also for spot focussing over a very small area?

 

[Kit.]

DPAF is phase detect.

But yes, so far a dedicated phase-detection sensor of SLRs is better for rapid focus. Theoretically, you might be able to implement such a sensor as a separate layer on a stacked mirrorless sensor, but practically, I think, we are still far from that.

 

[neuroanatomist]

Alan is referring to dedicated PDAF sensors embedded in the image sensor, spread throughout much of the sensor area behind masked pixels (the 'gaps' in the image are interpolated). That's how other manufacturers implement on-sensor PDAF and how Canon did so prior to DPAF (they called it Hybrid CMOS).

 

[BeenThere]

I’ve not used EOS-M. Can a user enlighten us on stills AF speed relative to, say a 5D DSLR? Noticeable differences in Tracking AF?

 

[neuroanatomist]

I find that my M6 tracks very well with what I'd consider simple subjects, e.g. a downhill skier (high contrast subject with dark clothes against snow, not moving super fast). It does decently with more difficult subjects, sometime can't keep up...but I wonder how much of that is the native STM lenses, which is pretty much all I use on the M bodies.

The M6 AF performance isn't up to the level of my 1D X with an L lens, nor do I expect that to be the case.

 

[3kramd5]

Notionally, I struggle to see how a masked pixel will outperform a split pixel.

 

[Random Orbits]

I'd like to see Canon being able to use DPAF only, but I don't think there is enough computational efficiency/power to pull it off. It'd also be neat if they could use multiple pixels to extend the baseline to allow the system to work at lower light levels or faster predictive autofocus.

 

[Mt Spokane Photography]

I use my 5D4 and my SL2 primarily in live view mode, where AF is plenty fast for most of my subjects. It really works well foir lenses with TC's where there is little light available.

Canon has been working very hard to improve DPAF, so it will be up to the task. However, don't expect it to match PDAF, just like Nikon and Sony, AF will be not quite as good as a low end Canon DSLR.

DPAF tracking has greatly improved as well, I prefer it to PD tracking except for sports or bif where speed wins out.

Overall, a mirrorless camera from Canon or anyone else is going to be a case of "almost as good as" when compared to a similarly priced DSLR. Small size attracts some users, but not in the USA. I think that Canon is big enough and has such a huge customer base that they can offer a full sized EF compatible mirrorless as well as a compact one with a new lens series and small consumer / prosumer lenses. Don't expect "L" lenses for the small version unless it displaces the larger bodies. The biggest market for small mirrorless cameras is Asia, and price is a big factor there.