Bap Pixel Map

[Doug64]

Hi,

Just setting up my Zwo 1600MM Cool.

I've done a darks library and was wondering if you use Bad Pixel Maps with Cmos cameras, I used to use one with my DSLR.

I have read about someone making a Bad Pixel Map with Darks and Dark Flats but other people don't mention it.

I'm wondering what the consensus of opinion is

Thanks

Doug

[vlaiv]

You can make one, but it is really up to how you use it.

Bad pixel map is "contained" inside master dark, or rather based on set of darks you can identify all the pixels that are bad and treat them accordingly (usually you can either mark them as bad so when alignment of subs is performed, these values are not used and are interpolated instead, or you can do it prior to alignment - in calibration phase).

It is up to software to handle this, and bad pixel map is basically the same thing as dark lib, except you are not interested in dark current signal - only pixels behaving badly - like those that are dead (returning 0 value), hot (returning clipping max value) or stuck pixels - always returning same value regardless of signal capture. All of these can be inferred from set of dark and pixel statistics and it's up to software that you use to make appropriate action.

[Doug64]

7 hours ago, vlaiv said:

You can make one, but it is really up to how you use it.

Bad pixel map is "contained" inside master dark, or rather based on set of darks you can identify all the pixels that are bad and treat them accordingly (usually you can either mark them as bad so when alignment of subs is performed, these values are not used and are interpolated instead, or you can do it prior to alignment - in calibration phase).

It is up to software to handle this, and bad pixel map is basically the same thing as dark lib, except you are not interested in dark current signal - only pixels behaving badly - like those that are dead (returning 0 value), hot (returning clipping max value) or stuck pixels - always returning same value regardless of signal capture. All of these can be inferred from set of dark and pixel statistics and it's up to software that you use to make appropriate action.

Thanks for the reply

Doug