Sensor Anlysis Read Noise Question

[sdl]

Hi, I have a question about how to interpret read noise using the sensor analysis tool.
I have just purchased the 2025 version of the ASI2600MC Pro and ran sensor analysis on it.
First, I ran it at room temperature with the camera reporting around 21C.
I then ran it with cooling set to -10C.

I expected to see a significant difference in the read noise but I see very little.
See the attached file that contains the data.
Can anyone explain why the read noise did not drop once the sensor was cooled?

Thanks,
Steve

[Ardsley Astro]

Hi,
The read noise is not affected by cooling the camera. Only dark current noise.

Thanks

Anthony

[sdl]

Ah, ok. I assumed that the dark current would be factored into the read noise.
Thanks,
Steve

[admin]

Hi Steve,

read noise is all about the minimum possible noise in a frame that comes (largely) from the read out electronics. It's measured with very short frames to deliberately exclude any thermal dark noise from the measurement. Thermal noise has to be treated separately, with dark frames or hot/cold pixel removal helping to eliminate it.

cheers,

Robin