UPDATE FROM MABULA
I have had a very rough 2 months unfortunately health wise. I was struck 3x in a row with bacterial infections. The second infection occurred  after a routine hospital checkup and I became very sick. I had to rest and take a lot of antibiotics. Once I was recovering and restarting work 1 month ago, I again became sick. The infection was not yet gone, so even more antibiotics and rest was needed. Needless to say, it took a lot of my energy and I needed a lot of rest.
Finally, the infection is really gone and my energy is coming back step-by-step now and I have started work again. I am terribly sorry to have kept you waiting for support. I will address all outstanding questions and e-mails step-by step and will be on the forum daily from today.
APP 2.0.0-beta47 will come soon as well, a lot of work was already completed before I became very ill, so the release is also nearly ready for you. Beta47 will be much faster actually. Many workflows will be more than 2x faster, mosaics can even be 10x faster than before because registration really received a major boost... all compared to beta46. Â Before I release it, I will make sure that everything is working properly and then I will release it.
Hi there,
I hope you are doing great.
I wanna have some questions regarding Dark Frame Scaling.
I am a DSLR user and do Astro and Deepsky Astro for enjoyment. I know the limitations of uncooled DSLRs.
I understand all the basic concepts needed for this hobby. As summer here, DSLR sensors produce a lot of thermal noise and hot pixels. During winters, sometimes I never take dark frames but dither manually (i have a star tracker, but I can do it on both axis) as the temperature was 5-15 degrees below zero. I try to dither after every few frames no matter the season I shoot.
But now its summer/rainy humid season and now the temperature is approx 28C to 35C.
So, the point is, if I make a master dark for 50-100 frames with 5 min subs at ambient or room temperature (between 25-30C/ different night/day, can I use them for the whole summer season?
If yes, then what ISO should I pick? Does it matter for dark frame scaling? Or will it work if I make a master dark from my all darks that I have taken so far at different temperatures, seasons, sub-length, and ISO? what would be a good strategy?
Please share your experiences.
TIA
Hi Aditya,
yes you can use darfkrame libraries. As a rule of thumb, noise level doubles each time when temp raises by 7C on DSLRs. However, this relates to the sensor temp (which is more constant once the Cam is working a few min), not the environmental temp. The usual advise is to have masterdarks for each 2-3C steps, in Your case You could get waway with 28C, 31C and 35C and pick the closest. I think the scaling only works well with ISO & exposure time changes, which behave more linear, not with temp which is very non-linear and strongly depending on the Cam. Note: You need to renew the libraries once or twice every year.Â
Clear skies,
Jochen
@aditya_photos Adding to Jochen's excellent answer: dark frames need to have the same ISO as the lights and preferably also the same exposure time. If the exposure time is different then you'll need bias frames of the same ISO as well.
Wouter
