Hot Pixels

[Bill1054]

Absolute PI newbie with first try at data reduction.  My dark frames (600 sec, minus 20 degrees from STL 1100M) have a fairly uniform scattering of hot pixels.  After calibration and integration of lights, these hot pixels are still present.  At what point am I supposed to eliminate them?  Clearly I'm missing something obvious.

Thanks,
Bill

[biosif]

Hi Bill.

First start an process named CosmeticCorrection, and then mark like in the image capture 1, and make an Process01
And then open Batch Preprocesing, put all your image and then mark like in image capture 21.
All your hot pixel will be remouved automatic.

 

[jkmorse]

Bill,

Biosif has it exactly right.  Also, as a newbie, be sure to check out Harry's Astroshed website which has great tutorials for beginners.  I also have built a workbook of over 50 pages of proposed workflows, tool tips, etc that I happily share with others.  If you are interested just drop me a line at jkmorse57@gmail.com and I will send you my latest version (Rev38).

Best,

Jim

[CharlesW]

I personally don't have a lot of success with Cosmetic Correction. I can never hit that spot where hot pixels are gone but I haven't started adding in artifacts. So I did some research and I found David Ault's PowerPoint presentation on hot pixel removal using Pixel Math http://trappedphotons.com/files/Presentations/Advanced%20PixInsight%20PixelMath%20Operations.pdf.

I calibrate my lights, then load all of them into a Image Container, create a Pixel Math process with David Ault's numbers above, and remove hot pixels that way. It gets rid of all the hots without adding any artifacts as far as I can tell. Not exactly a newb way to do it, maybe not even the right way but it works.

[Bill1054]

Thanks, gents, for the sage advice.  I'm excited to advance to the point of even limited success with PI.  This forum certainly is friendly!

Bill

[Stu]

Make sure you are dithering your images.  That will do a lot in getting rid of your hot pixels with your sigma rejection. 

[Philip de Louraille]

I have created a while back a DefectMap but not all the hot pixels are on it. A few got missed.
I have gotten their positions. What would be the best method to add them to the current DefectMap.fit file?
Basically, I want to add a black pixel to each (x,y) position of the fit file.

[sreilly]

To add to an existing defect map open Cosmetic Correction. Then at the bottom check "Use Defect List ". Load the map first and then input the location, decide if Row or Column, and hit Add Defect. Make sure to save all additions before you exit.

Steve