Dark frames for ZWO 120MC camera?

[michaelmorris]

I'm just finishing setting up my All Sky Camera based on a ZWO ASI 120MC camera.  I've identified that I really need to take some darks.  The capture software (Allskeye) doesn't have a facility for taking darks, what software can people recommend for taking dark frames and for creating a master dark in FITS format?

Thanks

[Cozzy]

Michael,

you could use PHD to make a darks library, can't for the life of me remember what format it saves in. HTHs

 

Tim

[Oddsocks]

Hello Michael.

On the various academic astronomy courses I’ve taken the recommended processing software is Imagej which is free, you can create your calibration frames in .fits format in that, and do all the usual post processing steps too.

The downside of Imagej is that it was written by scientists for scientists, and written originally for microscopists, with astronomy tools added later.

As a result Imagej needs a bit of work by the user to understand it and get the best out of, documentation is spread across several academic sites and requires some tracking down with many hyper-linked documents no longer existing. 

That said, it is still the only totally free astronomical image processing package that will run on any platform (being written in Java) that can produce finished images to the same level of professionalism as many off-the-shelf paid-for processing suites.

Many academic institutions maintain sets of specialised plug-ins that you can download for free that offer extra astro based advanced functions so as you get hooked into Imagej you may find yourself spending hours playing with new tools and pouring over dense academic papers that explain them (I know....must get out more....!).

If the above has not put you off, the link to Imagej home page is here:

https://imagej.nih.gov/ij/

And an introductory documentation page here:

http://www.astro.physik.uni-goettingen.de/~hessman/ImageJ/Book/index.html

When visiting Imagej web pages you may also find references to a a related variant of Imagej called Fiji, also free, which is an updated and extended image processing suite. Fiji does all the same astronomy functions as Imagej and the documentation is often better written as a wiki source  but it was not the recommended programme on the courses I took as it is a much larger programme with many added tools and plug-ins already included in the download that didn’t have much relevance for astronomy, at least that was the case five years ago, things may well have changed since then. If you wanted a look the Fiji download page is here:

https://imagej.net/Fiji/Downloads

William.

[RolandKol]

hmm... Most likely you can use the same AllSky software,

Simply, cover your lens and do Dark subs ( more is better, but not less than 20) with the same Exposure time, Binning (and other settings) you going to use (or used) for Photography.

PHD, as mentioned above, will automatically create your Master Dark from collected subs, but it will be trickier to keep the same settings you use in AllSky.

I would suggest to take darks with AllSky and stack them using Deep Sky Stacker- DSS (you will need Bias subs also)

Simply add all you darks, bias and few light subs to DSS, and stack all... DSS will produce MasterDark and MasterBias for you while stacking Lights.

P.S.

Never tried ImageJ, but I will

 

[Stub Mandrel]

You can create a master dark in Sharpcap and it will subtract it in real time. You can also use it with PHD.

But yes you can make your own just by doing a run with the camera covered and keeping track of what subs are what.