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True dark current

PostPosted: Mon Oct 06, 2014 11:23 pm
by kalasinman
Ok, I previously happily hacked the firmware of my D5100 with all the astro pertinent goodies. My version A-1.02. I have the 1.01 version with the True Dark current hack, which I want. The camera, refuses to upgrade as a later version is already present, apparently. What to do?--Jack

Re: True dark current

PostPosted: Tue Oct 07, 2014 4:28 am
by astronomer
Impossible. Make sure you have a full battery. The camera will not check firmware version.

Re: True dark current

PostPosted: Sun Oct 12, 2014 8:14 pm
by kalasinman
OK, my bad. I had the file in the E: root instead of the DCIM folder. Sorry. So I got it updated. Everything looks ok , even JPGs, but noting "Now you could use dark frame at different temperature or exposure time, or even taken at a different day, making it possible to collect more photons from the deep space. "
I am attempting to take new master darks, and they are very pink. Histogram shows channels not aligned. Is this a problem? Could I use these anyway and have one master dark that could be used to restack all my old subs?
Haven't had the chance to get a clear night to try with the new patch in real conditions.--Jack

Re: True dark current

PostPosted: Sun Oct 12, 2014 9:10 pm
by astronomer
That's just JPEG preview treating 0 as black point. We haven't fix the JPEG engine yet. But it should bother.

Old subs are not compatible. It is clipped and scaled.

Re: True dark current

PostPosted: Mon Oct 13, 2014 4:11 am
by kalasinman
Ok! Really excited about this. I made some darks at different ISOs and exposures today from ISO 400 to 4000, and compared them, even made some bias frames at 1/4000, all noise pips were just the same right through! I am concerned the the color channels aren't aligned, producing a very pink image. When I take some actual lights, as the darks and biases are all the same, can I just use one dark in DSS? Can I skip bias frames? Will they calibrate my flats? Your recommendations most appreciated.--Jack

Re: True dark current

PostPosted: Tue Oct 14, 2014 6:13 pm
by astronomer
Hi,

Please do not double post, sometimes we are too busy to reply.
And for this post you could just follow in the dark current tool thread.

Now, regarding your problem, I would use all bias, dark, flat and light. Because dark current can be uneven, subtracting the bias from all the rest makes it possible to scale.

Best,
astronomer