Hi,
Below is my Cosmetic Correction setting and explaination:
Cosmetic Correction
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CosmeticCorrection process
Add Files - /calibrated
Output directory /cosmetic
Click CFA if OSC
Select Master Dark
Double-click a light frame and auto-stretch
Hot Pixel Threshold - Enable
Apply Global
Debayering done later in the pre-processing workflow. After colour images are Debayered, you will not need to use this option anywhere else. If your light frames are monochrome images however, keep the CFA images option disabled.
Since we have a master dark to work with, we may not need to enable the Use Auto detect option below Use Master Dark.
That option is particularly reserved for no dark frames as low-noise Sony ICX694 sensor. Use Auto detect is helpful for extra clean-up.
To optimise our working speed, we should define a preview box around an area of the image that shows quite a few hot pixels (seen clearly as outliers as bright white single pixels that are clearly not stars). Also set the newly-created preview box to active so we are only seeing the preview box area.
With this set up, we click Real-Time Preview on CosmeticCorrection to get a window that shows us what is happening to the hot and cold pixels as we tweak settings, but only within our preview box area (which speeds up the updating as we tweak settings!).
First we click Enable on Hot Pixel Threshold and then decrease the Sigma value by using the slider. As we do this, we observe the real-time preview window to see how our hot pixels disappear.
Avoid Sigma values that are way too low as otherwise it will remove an unnecessary amount of pixels. You can also increase the Qty value by using the slider to remove more hot pixels.
You may check if there are any cold pixels worth removing by clicking Enable on Cold Pixel Threshold and tweaking this afterwards. Keep in mind however that this may not be required
You may notice that having used the master dark to remove hot pixels was not enough as there are a good number of hot pixels left over. When this happens, you may wish to also use the Auto Detect function.
To do this, simply click to enable Use Auto detect. You can then enable Hot Sigma and tweak the value with the slider or by entering a new value manually. A lower value is more aggressive at removing hot pixels so generally avoid values below 1.0. The higher the value, the better, so long as it does the job for your image. As for cold pixels, you can enable Cold Sigma to help further.
The Use Defect list option can be used to point out where bad columns or rows exist within your image. I find this is not necessary if you have a good master superbias and master dark that in essence present these bad columns and rows as well, as they would be removed by virtue of calibration.
Close real-time preview and image. With Cosmetic Correction still open, click Apply Global to apply these cosmetic correction settings to your light frames and output them to the /lights/cosmetic
We are now done with the calibration and cosmetic correction of the light frames and can now proceed to their registration (alignment) and integration (stacking). However, if your light frames are colour images from a one shot colour camera, you will first need to Debayer them.
Look up
John
