Author Topic: CosmeticCorrection question  (Read 1150 times)

Offline joelshort

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CosmeticCorrection question
« on: 2015 October 05 14:04:50 »
When using AutoDetect in the CosmeticCorrection process, is there a way to see how many hot and cold pixels the autodetect process is seeing?  How does one know what is an appropriate number of cold pixels to remove?   It's not obvious to me like hot pixels are.

The issue behind this question is that I have no idea how many cold pixels are typical for my ccd (SX-694 Trius).
Joel Short
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CFF135 f6.7, SV80ST, G3-16200M, QHY163M, QHY183M

Offline MikeOates

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Re: CosmeticCorrection question
« Reply #1 on: 2015 October 05 15:21:03 »
Joel,

Yes, just open one of the subs that you are about to perform the CosmeticCorrection on. Make a preview of a small section of the image, small enough so that you can see individual pixels.

Open up the CosmeticCorrection process, and select the preview icon at the bottom, (the open circle).

Now tick "Use Auto detect" and adjust the sliders, you will see the pixels that are being affected.

Once you have decided on the setting, close the preview and the sub frame and load the subs into the CosmeticCorrection window with the Add Files button. Set the output directory and click on the solid circle icon at the bottom left to perform the process.

Mike


Offline joelshort

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Re: CosmeticCorrection question
« Reply #2 on: 2015 October 05 15:34:01 »
Thanks for the reply Mike but it doesn't answer my question unless I'm missunderstanding something.  I know how to use the sript.  It's easy to see the hot pixels that are being corrected, but it is not easy to see the cold pixels.  If I use a master dark frame I can see the hot and cold pixel count as I adjust the sliders.  That's not true of the autodetect. 

When I use the master dark frame for calibration the slider for cold pixels jumps from 0 cold pixels to thousands of cold pixels with only a slight difference in the sigma.  I was hoping that autodetect could automatically identify how many cold pixels there were to give me an idea of about how many I should expect, but I see no way to number the hot or cold pixels in the autodetect function. 
Joel Short
www.buckeyestargazer.net
CFF135 f6.7, SV80ST, G3-16200M, QHY163M, QHY183M