EOS 7D Noise at different ISO settings

Not long after I got my 1Ds3 I heard that noise levels were lower at whole stop ISO settings, A quick test confirmed this and I have it set to whole stop steps rather than 1/3 stop (100,200, 400 rather than 100,125,160,200,250 etc.)

I’ve now repeated this with the Canon 7D and the results are not so obvious

Article Link: Whole or 1/3 stop ISO steps for the 7D?

I downloaded a 30 day trial of CS4 to be able to use ACR for this test, like before.

See also: Original fractional ISO test with 1Ds3

  • Only just found this and hence the earlier 1Ds3 test. Prompted by it, I did similar with my 30D and 5D, and plotted RAW file size against ISO, on the assumption (fair ?) that more noise means a larger file (I did also do the +4 stops exposure in processing in Lightroom, so I could see the difference). The 5D results were just as your 1Ds3, showing dips in noise/file size at ISO 100, 200, etc. The 30D also showed this pattern, still at whole stops, but the dips are at ISO 160, 320, 640. Curious !

    Thanks for a most interesting and informative website.

    • Thanks – I know the technical validity of some aspects of my testing has been questioned, but I still feel they are a valid contribution to how people process their ‘everyday’ images.