Hot pixel question

[David Boyd]

I recently made a new dark frame and hotpixel.lst file with ISIS. I was therefore surprised to see what looked like the effect of a hot pixel on a spectrum I recorded two days ago. When I looked at the image file, there was indeed a hot pixel sitting right in the middle of the spectrum with a value of about 5800 compared to 3600 in surrounding pixels. I measured its x and y coords and checked the hotpixel.lst file. The hot pixel was indeed listed in the file.

So why did the hot pixel filter not remove this hot pixel? Am I doing something wrong?

I then tried the new cosmic ray filter facility which Christian introduced in v5.5.0. I switched this on in the General tab and experimented with the coeff value in the Settings tab. With the coeff set to 5000 or less, this did remove the hot pixel.

Why did the cosmic ray filter do the job when the hot pixel filter did not?

Can anyone explain what is going on here?

David

[Christian Buil]

I suppose you have enter the name of the cometic file in the "Cosmetic file" field (General tab) ?

Christian

[David Boyd]

Yes, I have.
David