Dark Frame Scaling ??

[Jockinireland]

I have been looking into the Dark Frame Scaling process within Astro Pixel Processor.

Now this seems to me like it is a bit of a godsend fo DSLR images. The way I'm reading it, I no longer need a dark frame library of hundreds of images taken at specific ISO, temp and exposure duration to match whatever set up I use on a given night. All I need to do is take a good set (100 frames perhaps) at one ISO, one temp (or all within a reasonable range, say plus minus 2 C) and at one long exposure ( say 5 mins as that is longer than most things I'll do just now) Then have a good set of bias at the same ISO, make master bias and master dark from these then use them and the dark scaling option in APP to calibrate ANY ISO/temp/exposure I have.

However, this just seems too good to be true. And my mother taught me at a very early age that if something seems too good to be true it usually is!!

So, am I misunderstanding this? Does it work well? At all? Anyone with some experience of using it to warn me of the pitfalls?

Thanks and regards

David

[Stuart]

Yes, although it's always better to match your darks if you can. Also scaling only works for time, not temperature.

[Jockinireland]

Yes, although it's always better to match your darks if you can. Also scaling only works for time, not temperature.

Thanks Stuart. Do you use APP? Its just that on the support forum for APP the software designer, Mabula seems to state that he has written it to scale ISO/gain, time and temp. But maybe I'm not understanding it properly.

Regds

David

[Stuart]

Hi David,
No, I don't use a DSLR. If they can scale ISO/gain,time and temp that's news to me. I was always taught that the only thing that is linear is time of acquisition. Seems to me that if you have different variables (time, temp, iso) then it would be much harder to scale.
Stu

[Jockinireland]

Hi David,
No, I don't use a DSLR. If they can scale ISO/gain,time and temp that's news to me. I was always taught that the only thing that is linear is time of acquisition. Seems to me that if you have different variables (time, temp, iso) then it would be much harder to scale.
Stu

Hi Stuart, thanks for that. To be honest thats what I thought too (although I'm not really that knowledgeable)but the APP FAQ seems to be fairly clear - I just wanted to hear others thoughts make to sure i was going completely off line . Here is a link to the relevant FAQ page if you are interested.

Thanks again for your input.

David

[Jockinireland]

I seem to have missed the link. Here it is
https://www.astropixelprocessor.com/com ... e-scaling/

Rgds
David