Canon Dual Pixel Liveview Autofocus

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funkboy said:
jasonsim said:
Does it have AFMA?

check the dprevew preview.

The 70D does have AFMA for the traditional 19 point AF sensor (unlike the 60D), but the dual pixel system doesn't need AFMA because the AF sensor & the image sensor are one in the same.

AFMA is certainly not well advertised, it wasn't in the specification, but is welcome.

Hopefully the new dual pixel AF is accurate, contrast detect in the 5D MK III has been shown to be inaccurate. I think we will have to wait and see, the tolerances of a in photosite phase detect system would need to be almost impossibly accurate, so there is likely some sort of calibration, and that implies mis-calibration is possible.
I'm sure we will find out.
 
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neuroanatomist said:
Mt Spokane Photography said:
AFMA is certainly not well advertised, it wasn't in the specification, but is welcome.

Canon USA doesn't list AFMA in the specs of any camera with the feature. Canon UK does, though.

The DPReview hands on preview also mentions that Canon have reinstated AFMA, so I'm guessing that this is an omission from the Canon USA website.
 
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funkboy said:
If this thing is already doing pixel-binning for 40 half-pixels, wouldn't it be trivial to have it pixel-bin 4x and make a very nice noise-free 10MP image? I'm sure that Digic5+ can handle that...

I'm pretty sure that's what the C300 does (I'm not sure if it straight-out bins them or does something else fancy, but yes, it can be done...)
 
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funkboy said:
If this thing is already doing pixel-binning for 40 half-pixels, wouldn't it be trivial to have it pixel-bin 4x and make a very nice noise-free 10MP image? I'm sure that Digic5+ can handle that...

In the telecom world anyway, having 4 signals to work with and compare makes a huge difference in the quality of the transmission.

The 70D has an mRAW mode with 11Mpix RAW file output - it isn't exactly 2x2 (sub)pixel binning which would lead to rectangular pixels ...

Here the information from the Japanese Canon website:
RAW: 5472×3648 20 MPixel 24 MByte
mRAW: 4104×2736 11,2MPixel 19 MByte
http://cweb.canon.jp/eos/lineup/70d/feature-highquality.html

The difference in file size doesn't justify using mRAW alone - perhaps DPP runs faster on the 11MPixel files so you can use an older PC for a longer time.
But if RAW stores the real raw information so it might be a better idea to use the full resolution and scale the images down to 10 MPixels afterwards! This is sth. like binning on a irregular way.

EDIT: Or use 5MPix: 2736 x 1824 Pixels - so you got 1 red, 2 green and 1 blue sensor pixel for each image pixel! - same resolution like the first implementation of foveons and real full color image pixels. In some cases probably helpful to get cleaner colors/contrasts with monochromatic light sources or software red filters.
 
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