Type of Dataset Question using a OSC Camera

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Type of Dataset Question using a OSC Camera

Postby sandconp » Sun Dec 08, 2019 6:02 pm

When I open my fits file I get a message on what type of file I am loading. The choices are linear, Linear OSC and Non-linear sRGB source. Well that last choice is Non-Linear so I can rule that one out since I know it's a linear file. The camera I am used was a ZWO ASI 183MC One Shot Color. So I decided to choose that option but when I process with Dev or Auto Dev, the image is coming out black and white with no color. So I then choose just linear, and I get color in my image.

Could you explain why the Linear OSC is showing the image with no color?
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Re: Type of Dataset Question using a OSC Camera

Postby admin » Mon Dec 09, 2019 10:38 am

The second option engages Compose mode (you will notice it is lit green). Compose mode makes StarTools process luminance and color separately, yet simultaneously. In this mode you mostly work on the luminance (which is, of course, mono) to bring out detail until you hit the Color module, which then brings in color.

Your OSC (or any camera with a Bayer matrix) records, for every 2x2 patch of pixels, only one red, two green, and one blue sample. These are then interpolated during debayering. Because you are recording twice the amount of green samples, StarTools can reweight the importance of the green channel to reflect its superior accuracy for describing detail. And this is precisely what is happening; a synthetic luminance dataset is automatcially created for you with higher weighting for the green channel, while the color information is decoupled for later use in the Color module.

Of course, StarTools can only (correctly) do this for you if the channels have not been tampered with beforehand. That means no color balancing or any camera matrix manipulations.

Compose mode (which is normally accessed through th Compose function) is extremely powerful, while making very complex composites as easy to process as a DSLR set. E.g. if you know how to process a DSLR or OSC dataset, you now know how to process a complex LLRGB composite too.

Does this help?
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Re: Type of Dataset Question using a OSC Camera

Postby sandconp » Tue Dec 10, 2019 3:35 pm

The second option engages Compose mode (you will notice it is lit green). Compose mode makes StarTools process luminance and color separately, yet simultaneously. In this mode you mostly work on the luminance (which is, of course, mono) to bring out detail until you hit the Color module, which then brings in color.

I don't notice the 2nd option is lit green ? (Linear, from OSC/DSLR with Bayer Matrix and not white balanced).

At any rate I am using a ZWO ASI 183MC OSC color camera so would the second option improve my image? I used the first option Linear, and I got great results on my Flame and Horsehead Nebulas.

https://www.dropbox.com/s/2khan6wp1c0zu ... 9.jpg?dl=0
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Re: Type of Dataset Question using a OSC Camera

Postby admin » Tue Dec 10, 2019 3:56 pm

sandconp wrote:The second option engages Compose mode (you will notice it is lit green). Compose mode makes StarTools process luminance and color separately, yet simultaneously. In this mode you mostly work on the luminance (which is, of course, mono) to bring out detail until you hit the Color module, which then brings in color.

I don't notice the 2nd option is lit green ? (Linear, from OSC/DSLR with Bayer Matrix and not white balanced).

At any rate I am using a ZWO ASI 183MC OSC color camera so would the second option improve my image? I used the first option Linear, and I got great results on my Flame and Horsehead Nebulas.

https://www.dropbox.com/s/2khan6wp1c0zu ... 9.jpg?dl=0


That looks great Conrad! If you Bin the dataset some, you could probably use deconvolution to tease out more fine detail.
Apologies, I meant the 'Compose' button text is lit green when you choose the second option. Indeed, choosing the second option should give you a slight bump is signal fidelity due to the reweighting.
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