This could be a stupid question.....

[MadMailMan]

What is the "native" resolution of the Canon 7D CMOS? I was lying in bed in the wee hours of this morning thinking about this. DPReview has the 7D CMOS as 19 million total pixels but only 18 million effective pixels. So are 1 million pixels on strike/holiday/gone fishing? Why make it 19MP when it can only use 18MP?

This brought me to my next question. When you set the 7D to MRAW does it use a smaller portion of the CMOS? I'm guessing that would change the FOV so no. So then does it just use say every second pixel?

I need more sleep.

 

[bwana]

Total pixels are, as the name implies, the total number of pixels on the sensor. Effective pixels are those used to compose the final image - usually omitting the ones on the very edge of the sensor.

M-RAW is a down-sampled RAW image. You get many of the benefits of shooting in RAW but end up with a smaller image. On my 7D I usually shoot mraw and/or full res jpeg unless I know I'm going to want large prints or will need to do some extra pixel pushing in post - in which case I'll shoot in RAW. Aspect ratio/FOV isn't affected.

 

[MadMailMan]

.... M-RAW is a down-sampled RAW image...... Aspect ratio/FOV isn't affected.

So the camera makes the image up by skipping every second (or third or...) pixel? This would kind of explain why the pixel-peepers observe improved crispness/clarity in MRAW over full RAW images. No? And why there is no change to the FOV or aspect ration.

 

[bwana]

This might offer some insight - http://www.learn.usa.canon.com/resources/articles/2011/eos_qt_small_raw_images_article.shtml

There is no real benefit from shooting in reduced res RAW files other than smaller files. you can also emulate the effect by pixel binning in post.

There's no change in FOV or aspect ratio because the sensor still remains the same size. Likewise if you shot the same image with a 7D and a 400D the image would be the same because even though one is 10mp and the other 18mp you're still using the same ASP-C sensor.