Canon EOS 5D Mark III Samples

Here, the Canon EOS 5D Mark III is compared to the Pentax K-5
Pentax K-5 which is the best performing cropped-sensor digital camera to date. All images below are 100% unmodified crops from their respective cameras. Both these cameras were set to F/5.6 in aperture-priority mode with fixed ISO and custom white-balance. As usual, each of these cameras was calibrated to give the highest quality and most realistic results possible.

These crops help determine which ISO settings can be acceptably used on these cameras. As image noise increases, most cameras compensate with noise reduction which introduces softness. The point at which a print become unacceptably noisy is a matter of personal taste.

Canon EOS 5D Mark III	Pentax K-5
	ISO 80
ISO 100	ISO 100
ISO 200	ISO 200
ISO 400	ISO 400
ISO 800	ISO 800
ISO 1600	ISO 1600
ISO 3200	ISO 3200
ISO 6400	ISO 6400
ISO 12800	ISO 12800
ISO 25600	ISO 25600
ISO 51200	ISO 51200
ISO 102400	It does not take much to see a noticeable difference between a full-frame and a cropped sensor. While ISO settings up to 400 show insignificant differences, the Canon 5D Mark III takes a noticeable lead from ISO 800 onwards. Towards the end of the range, ISO senstivity of the 5D Mark III shows a 2-stop advantage. As usual though, the extended sensitivty steps of these cameras are pretty much useless.