Hello,
I have questions concerning dark current and bias of the ASI294MC Pro. I’m using KStars/Ekos under Raspbian.
I set the cam to unity gain 120, offset 6. The histogram of a bias frame looks good, no clipping at zero, a mean of approx. 96 ADU (all ADU numbers given on 14 bit scale).
The (mean) dark signal of a 30 s dark frame is approx. 6.8 ADU higher than the mean of a bias frame. The mean of a 60 s dark frame is 7 ADU higher than bias. So the change from 30 s to 60 s is only 0.2 ADU. But from 0 s (bias) to 30 s I get 6.8 ADU.
Q1: Why is there such a high offset between 0 s and 30 s?
I’m using the ASI Indilib driver under KStars/Ekos. When I start the cam, bias frames have a mean of 96 ADU (with offset set to 6), which is as expected. After a few captures, all of the sudden I get bias frames which are all zero (all pixels exactly zero).
Q2: Is there an automatic dark subtraction which randomly kicks in? Maybe a bug in the driver?
Thank you in advance for your answers,
Best regards,
Bernd
