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Cosmetic correction is hurting my raw data  


Brown Dwarf Customer
Joined: 3 years ago
Posts: 8
March 29, 2020 20:00  

Dear Mabula/Vincent,

To describe the problem:

I load a raw frame and inspect it in the image viewer using the zoom functionality.

I then click on l-calibrated in the image viewer.

I then see the abbreviation CA appear behind the raw file which is somewhat strange because there are no calibration masterframes active at this moment. Going back to linear viewing does not make the CA go away.

Even more strange is that the raw file is hurt due to the enabling of cosmetic correction in the calibrate tab. Especially the hot and cold column correction options with the default value of 8 are the problem. Lowering this value significantly increases the problem, setting the default value to only 8.1 solves the problem!

First, is it normal that cosmetic correction is already applied once you tick the options in the calibrate tab and look at them in the l-calibration mode (hot pixels correction seems to work OK by the way)?

Second, shouldn't there be a warning to carefully inspect the raw files using l-calibration mode to check if the raw files will be hurt by activating cosmetic correction? This is highly important because all the following steps have this artifact included (also the final integration result). Besides, the issue seems to concentrate on the sky target itself which makes it even more disturbing.


Best, Ruud