Since the image is pretty dark (DUH!), I have pushed it six (!) stops in Photoshop (Image->Adjustments->Exposure) after applying a "Threshhold Level 1" correction to zero out RGB values of 1 - this makes it much easier to see differences. ACR does some noise/dead-pixel filtering even if it is set to zero noise reduction, and this is very clear if you compare to the DPP processed images. Javascript is used to "flip" the images so give it a few seconds the first time as the browser caches the image; after that, you can quickly go back-n-forth to compare.
An Internet Surfer sent me some dark frames from a Canon 5DM2, so I have added
those. This is a full-frame camera with a much larger sensor and therefore
not exactly a fair comparision to the crop format 50D & 7D. However,
the Canon 7D compares well to it, but size matters when it comes to
imaging sensors, and the 5DM2 is still the low noise champ.
P.S. I first used Photoshop Equalize, but that didn't provide a
similar comparision. One could also use Threshold, but
pushing 6 stops seems to provide an interesting comparision of not only
noise levels, but how dynamic range suffers at higher ISO's.
Photoshop CS4 was used to process the photos - note that ACR5.5 only has
a Beta profile for the 7D. DPP was version 3.7.
This is a brand new 7D and there is negligable dust on the sensor ... which would not have any bearing anyway.
Yes, I'm a bit of a gearhead ... on a related note, here's a
High ISO comparison of the Canon 7D and the 50D
Also, the Canon 50D can shoot fine pictures and did an excellent job in
Antarctica and Falklands & South Georgia Islands.
I welcome any comments/suggestion on all this -
back to the main Canon 7D versus 50D page