bias frame and dark frame levels at different shutter speeds - interest only

[astropixel]

I have attached a screenshot of 5 calibration frames taken with the same DSLR under the same conditions, except control of shutter speed. This may be of interest - the results are interesting.

Centre image for comparison - 100iso bias, 3 frames, 'zero' shutter speed. Arduino micro-controller scheduling shutter speed - on/off no delay

RGB ~480

Top left - 800iso bias, 3 frames, camera max shutter speed 1/8000 sec

RGB ~86

Bottom left - 800iso dark, 3 frames, 210 secs.

RGB ~3

Top right - 800iso bias, 'zero' shutter speed 3 frames - Arduino...

RGB ~278

Bottom right - 800iso dark 210secs 3 frames

RGB ~3

The darks are virtually identical regardless of the bias used.

Note: I'm not sure of the actual shutter speed using the Arduino - bypassing the camera electronics.

[Cleon_Wells]

Rowland, could you post a Debayered  ADU readout of your Bias level with the probe size set to 9 pixels?
I've attached a screen shot of bias and dark( iso400@120secC28 ) levels before and after Calibration.
Cleon
PS I some how managed to break STF during this experiment, STF will not change any of the open images.

[astropixel]

Happy to comply Cleon, but how do I set the probe size and how do you manage to keep the read out boxes visible and take a screen shot.

[Cleon_Wells]

Rowland, the Probe adjustments are set by clicking on the triangle located at the bottom/center of the PI screen, next to the Probe readout,

On my Mac, I take a screen shot with Preview of each screen with the different Probe locations and then use PS to crop and paste the different Probe displays to one of the screen shots.

Attached is a Dark sub from last night with the Probe size set to one pixel, this image shows what happens to hot pixels after the DeBayer process.
If your interested in learning more about the different DeBayer processes, check out Craig Stark's article.
http://www.stark-labs.com/craig/articles/assets/Debayering_API.pdf

Cleon

[astropixel]

I see what you mean. Good paper on debayering. Craig Stark has some good articles that are currently answering other questions. I am away on work until next week - earliest to fulfil your request.

Dithering comes to mind as an option for hotpixel protection in lights as we calibrate prior to debayering.