Getting the colour right

Questions and answers about processing in StarTools and how to accomplish certain tasks.
Burly
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Getting the colour right

Post by Burly »

Any tips for getting the colour right on m42 it could be i just havent got enough data 52x30sec subs always seems to be a bit on the red side.
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LanFeusT
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Re: Getting the colour right

Post by LanFeusT »

Post the FITS/TIFF file if you want, I can try and have a go at it to help!

Be sure to read the color module section, it explains how you can color balance your image. It's still probably the hardest thing to do in all of post processing though, for me at least ^^
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Re: Getting the colour right

Post by admin »

:text-yeahthat:
Ivo Jager
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Burly
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Re: Getting the colour right

Post by Burly »

Thanks that`s a great help https://www.dropbox.com/s/98ffafvmp9501 ... s.FTS?dl=0 had a quick tweak and colour does look better though the heart of image looks a little greenish blue but its a start in the right direction .
Burly
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Re: Getting the colour right

Post by Burly »

Mk3 bit better
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Re: Getting the colour right

Post by admin »

Hi,

Thanks so much for uploading the data - it's extremely helpful.

A number of things stand out. Firstly, the data appears to be stretched already. This greatly reduces what you can accomplish with StarTools (or other software), nor is color balancing possible anymore.

Would you know why the data has already been stretched?

If using DeepSkyStacker, have a read here for the correct settings and a quick-start workflow.

Once you have the right data to start off with, for M42 you'd be looking for a blue/green core (dominated by O-III emissions and reflection nebulosity of the blue giants lighting up the core), a deep red shockwave south of the core and purplish/red Hydrogen alpha emissions. In all likelihood, you have recorded all this, it's just a matter of pre-processing the data correctly before handing it off to StarTools (or any other software).

Hope this helps!
Ivo Jager
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Burly
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Re: Getting the colour right

Post by Burly »

Thanks for the help Ivo I will redo data this week , not sure why it's stretched I will go back over settings I thought I'd got correct settings in DSS , thanks for taking the time much appreciated I will repost link once I redo data .
Burly
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Re: Getting the colour right

Post by Burly »

redone stack ivo heres the link redone through DSS hopefully its correct this time if you can look at the data and tell me if it looks unstretched ,https://www.dropbox.com/s/05cf7toeu73ff ... 1.FTS?dl=0 ,how could you tell the data looked stretched, out of curiosity.
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Re: Getting the colour right

Post by admin »

Hi,

Looking at so many data sets over the years, it's becomes easier to tell when different aspects of the same image seem to have their brightness closer together than normal. Typically, when dealing with linear data, the 'wings' of M42 are much harder to see than the core (or just invisible), while typically only the brightest stars are visible.

Unfortunately, it appears to me your latest dataset is still stretched and still has been color balanced as well. Can you compare the data you posted to the autosave.tiff (or autosave.fts) which DSS also produces?
Some stretch is being applied, while some sort of channel alignment option is still on as well... :think:
Ivo Jager
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Burly
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Re: Getting the colour right

Post by Burly »

Ok thanks Ivo I will take a look over the weekend obviously something going on in DSS that I haven't got right , I've set the matrix in the settings for my camera a canon 1000D so that should be correct , and unchecked set black point to zero ,set calibration settings to no I must be missing something obvious so I'll google DSS , cheers
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