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  • Confused in Image Calibration

Hi all,

I recently became highly interested in deepsky astrophotography and I felt lucky finding this platform.

In my post-processing workflow in PixInsight 1.8, I found myself very confused in the Image Calibration process.

The annexed image is an example. With the master calibration files downloaded from googledrive, I used ordinary parameters to calibrate the light. But when I inspect the calibrated light, I found that no hot noise pixel was subtracted but the calibrated light was even more noisier than the uncalibrated one.

Am I using wrong parameters, or am I using wrong calibration file?

I remember that the auto-calibrated lights from the platform obviously were cleaner.

Much appreciate for your helps.

Fernando

Problem solved, hopefully. By making master calibration files from raw by myself, and disable the Optimize option in Master Dark in ImageCalibration process, I got proper calibrated lights. 😀

I've tried disable the Optimize option before this but I always got totally dark pictures. I don't know the reason of the problem of my workflow as I'm still learning PinInsight.

Thanks!

Hi Fernando,

glad you've got it!
We provide the raw calibration data exactly for this reason. Usually it works best if you have Darks of the same duration as your light frames. Take a bunch of those (like 20 or more), and make a simple ImageInteration in Pixinsight, without scaling.

Then use this master to calibrate your light frames.

For flat frames, it is similar but you'd need to both use a bias and a dark master with optimization, as the exposure time for the flats varies. It's a little more tricky here 😀