A quick test to see the effect of Live View (and the heat it generates) on sensor noise during long exposures.
Below are 3 test images. The first is a reference image on a cold camera, and a short exposure. The second a 5 min exposure on a 'hot' camera where a 60 minute exposure had just finished (ie the camera was in use actually exposing for a full 60 minutes just before the 5 minute exposure was shot). The third image is also a 5 minute exposure but was shot immediately after the camera was left in Live View for a full 25 minutes.
It seems that Live View has a bigger effect on background noise than the sensor itself.
JJ
