[avandonk]

It occurred to me that by measuring a hot pixel at various temperatures you could then measure the sensors temperature directly by just measuring the same hot pixel.

I took a ten second dark at 400 ISO straight after turning on the camera at ambient 23.7C. The camera was then turned off and the fridge set to 15.0C. When everything equilibrated took another dark at the same settings. Repeated this for 10.0C and 5.0C.
Raw frames converted to linear tiffs and digitally developed in IP.
Below is a graph of fridge temperature vs pixel value measured from the same pixel obviously.

Now the interesting bit. If you then just turn the camera on and leave for about thirty minutes to equilibrate. The temperature of the sensor rises by 2.2C.

Set the camera taking 8min darks and when constant take another 10 sec 400 ISO dark. The sensor temperature has actually risen by 16C.

So when the Peltier cold side is -5.0C the environment in the fridge is -0.4C. The sensor when taking a continuous series of exposures is at 16.0C.

While the camera is exposing

Fridge Temp 8.8C pixel value 30,131
Fridge Temp -0.4C pixel value 19,664

This needs further exploration.


Bert