RAW vs MRAW vs SRAW

[snowbear]

Not sure if it helps but File types – RAW, S-RAW, M-RAW and JPEG - Canon Professional Network

 

[TCampbell]

One of the biggest reasons to avoid modes such as M-RAW and S-RAW (besides loss of detail) is that these modes are not well-supported by third party editing programs. Don't be surprised if your favorite editor (which might understand your camera's RAW format) does _not_ understand your camera's MRAW or SRAW formats.

The only _real_ RAW mode is the mode named "RAW" (no prefix... no suffix).

If you're asking if MRAW or SRAW perform "binning" (which typically would improve the signal-to-noise (SnR) ratio of the image)... I don't know. I've never tested that nor have I come across any articles that addressed it.

My "guess" is that it's not using true binning because that would imply something like 2x2 binning or 3x3 binning which would mean that "MRAW" should be half as wide and half as tall as full-resolution... but I don't believe that's the case. They may be using some partial binning algorithm. Typically whenever you down-sample any image you improve the SnR.

 

[UncleSteve]

So I was doing some indoor low light shooting with my 5DS R a few nights ago and I knew the photos would not be required to print at the size of a large scale poster. So, I shot on the MRAW setting to save some space and let my system run a little faster when editing (1600+ photos can be a lot). I was shooting at f2.8 ISO 2000 and a shutter speed of 200. What i noticed when in the edits is the noise was greatly reduced when compared to the full RAW files in the same settings. Lightroom and Photoshop had no issue working with the files either. Another side effect was an increase in buffer when doing long action shots.

I love the 5DS R, but it was getting really frustrating when not shooting in pure studio with flash to really get all the detail. Now that I have seen what happens with the MRAW I may find my self using that more often and only going to the full size when I know the prints will require such a file size. Just my two cents