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DSS with cls filter


malp

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I’ve recently started using DSS, so far with raws from an unmodified Canon EOs fitted with the astronomik clip-in cls filter (I’ve been using this filter/camera combination for many years but processed by other means). I’ve trawled through various past threads both here and on other sites but have not yet found a DSS processing solution to the problem. All the final processed images I’ve created in DSS have the green/blue tinge from the cls filter and many of the stars have a hole in the centre, this is a small crop from a stacked image. I’m currently trying a number of DSS processing options on one image to attempt to solve this. Anyone have experience of cls filtered files which they have solved in DSS?

All images I’m using have bias/darks and flats added. DSS registration on stars is perfect. Bringing r, g and b histograms together hasn’t solved the problem with regard to star colour.

Left image settings:

RAW/FITS Settings - Bilinear Interpolation; White Balance boxes not checked. Black Point box not checked.

Stacking - Kappa-Sigma clipping. RGB Channels Background Calibration.

Right image settings:

RAW/FITS Settings - Bilinear Interpolation; White Balance box checked Use Auto. Black Point box checked set to 0.

Stacking - Average mode. RGB Channels Background Calibration.

post-4759-0-25720400-1422270082.jpg

post-4759-0-19811500-1422272076_thumb.jp

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I don't think this has anything to do with DSS. Have you set a custom white balance on the camera as you need to do that or it will come out green & blue. The reason is that without a custom white balance, the camera doesn't know the filter is there & so you need to tell the camera that the green/blue is actually the white so it re-calibrates the white balance.

Stick the camera on your scope, put a white t-shirt or something similar over it & point it at a cloudy white sky. Once you've done that, go into your menu & find the custom white balance option & select the image you've just taken. This should fix your issue.

HTH,

Jeff

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I do not set a custom white balance in camera... I use the auto white balance settings as for option 2, but do not set the black point to 0 option. When I do set the black point to 0 option, I get the exact same oddness in the output (with either a cls, or the SW LPR which gives a pinky/red tint). 

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You are doing things correctly, but the filter you are using is designed for modded cameras, and WILL give a green tinge on an unmodded camera.

You need to use a custom white balance or get your camera modded, with a modded camera the colour balance is almost perfect, this is stated on the AStronomik website.

It can be put right in the post processing but it is not easy.

Take a picture on Auto mode in the midday sun, with sun behind you, (or on any bright day) of a grey photographic card, filling the frame, with the filter fitted, then use this image as your custom white balance, some people say to,use white card, but to do,it properly it should be a proper photographic grey card, I bought one from www.7dayshop.com for a few quid.

Hope that helps

AB

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