There have been a flurry of posts since the Mk3's hit people's hands of either problems or soft images. Until reading these posts I would have never thought of checking a sensor for dead pixels by shooting images with the lens cap on.
So I wanted to ask, in what ways do you test a new camera body for functionality? Any other checks you routinely perform like the dead pixel test above? Do you always do an AFMA with each lens in a closed environment?
Before concluding there are dead pixels, be sure the sensor is clean, as a speck of dust can look just like a dead pixel. A brand new camera shouldn't have dirt/dust on the sensor, but it could happen. Cleaning up a dirty sensor is relatively easy, whereas dealing with a truly dead pixel is a much more serious issue.
I use LensAlign MkII for AFMA, but it is a tedious process that requires careful setup and patience. Prime lenses are easier to do than zooms, as most cameras host only one AFMA setting. The new 1DX and 5D3 have separate W (wide) and T (tele) settings that supposedly improve the overall calibration at intermediate focal lengths. I'm due to get my 5D3 on 4/2 and will be testing out my new 24-105 as well as my EF 70-300 DO lens.