CosmeticCorrection Settings with Master Dark?

[jkmorse]

To date I have been using CosmeticCorrection with the Auto Detect routine and defined sigma ranges for rejection.  However using a Master Dark should give more precise control.  My question is, what are the guidelines for setting the hot pixel and cold pixel threshold parameters?

If anybody can explain or point me to a post that covers that, I would really appreciate the help.

Best,

Jim

[chris.bailey]

Jim

I set mine applying a master dark CC correction to a copy of the master dark. Turn on RTM and adjust sigma until all the errant pixels in the master dark vanish.

Chris

ps I find using Autodetect to have an edge as I find there are several randomly hot/cold pixels on my CCD that don't appear in the master dark.

[jkmorse]

Chris,

Thanks.  I have been playing with the settings but like you, I seem to always get a cleaner image when using Auto Detect and thought I must be missing something in how I set the parameters with a Master Dark.  Still welcome others with possible solutions, those yours makes sense.

Best,

Jim

[Warhen]

Guys, Note that either by design, or serendipity that you can use both Auto Detect and the Master Dark methods. I find that AD at the default Sigma of 3 works very well for my data, but also using a Master Dark eliminates even more errant hot pixels. Just slide them away without being more aggressive than you need to be. Take the time to define column defects in the Use Defect List section below, and you will get a fabulous cosmetic correction after calibration!

[Harry page]

Hi
Of course you may get some cosmic ray hits that are not in your darks !!

But the best way I have found is that I use a 20 min dark for all my CC (that are below 20 mins of course) even for say a 5 min

sub as there are usually more in the 20 min than is needed , but less errant hot pixels slip the net  8)

I find the auto version can work well but is slow

Harry