New PI user - asking for help in starting postprocessing

[rfriedrich]

Hi PI Enthusiasts!
My name is Roman and I do Astrophotography for about 2 years. Until now I just do my best to improve my RAW files.... but postprocessing my pictures is still a totally open topic - unfortunately. May be an advantage because I also do not have any glue of Photoshop. What I did so far is to do some DeepSkyStacker stuff but of course without more processing I will never get to my personal "pretty picture".
I discovered PI and I took the decission that this great Software will be my one and only tool for my personal path to postprocess my pictures. I already watched the video tutorials and read many informations but as always, I have the problem that some questions pop up or some steps are missing in the explanations - just for me as a beginner.

I kindly ask for help starting my PI journey with bringing in step by step workflow questions I discovered until I get to the point - "Save as" ;-)
My second hope is that this forum is not bored about the 17453th question how to start. I try always to start my questions with my way I tried before and then ask how I could improve this until I can close up and go move to the next topic.

So for my first entry here I kindly ask for feedback to my preprocessing steps I tried so far.

I start doing the following for getting Masterframes and I kindly ask you all to give me some feedback and perhaps some (for me understandable) hints to improve.

Master Dark creation
****************
1.) Image Integration
select all Dark Files

Image Integration:
-------------------
Combination Average
Normalize: no
Weights: Don´t Care
generate integrated image: yes
Evaluate noise: No

Pixel Rejection(1)
-------------------
Rejection Algorithm: no rejection
normalization: no
generate rejection maps: yes
clip low pixels: yes
clip high pixels:yes

Pixel Rejection(2)
-------------------
Sigma low = 4
Sigma high = 3

--> Process Master Dark & save as Master Dark

Master BIAS creation
*****************
same procedure and settings like Master Dark previously


Calibration of FLAT Files with Master Dark and Master BIAS
*********************************

1.) ImageCalibration
Add Files - all FLAT Files
taking Master BIAS and activate Calibrate
taking Master Dark and activate Optimize und Calibrate aktivieren (CFA pattern = Detect CFA)
--> Processing


MASTER FLAT
************
1.) Image Integration
take all previously calibrated FLAT FILES

image integration:
   combination: average
   Normalization: Multiplicative
   weights: don´t care

   generate integrated image: yes
   evaluate noise: no

pixel rejection (1)
   rejection algorithm: Winsorized Sigma Clipping
   Normalization: no normalization

pixel rejection (2)
   Sigma low: 4
   Sigma high: 4

--> processing and save as Master Flat

************

this is my so far tried way of preprocessing MASTER Frames to then use the BatchPreprocessing Script to get the "postprocess" ready RAW File.

Any Feedback on this workflow so far from you side would be helpful


I have 3 questions after this workflow so far which I also ask for feedback from you:

1.) Do I have to DEBAYER my Canon CR2 RAW Files with the DEBAYER Function in PI before starting any step?

2.) The Integrated Picture which I get from the BatchPreprocessing Script is perfectly stacked BUT really really noisy. All steps I tried so far made it even worse or did not help. (Excelt the Backgroud Extraction which perfectly filtered the massive gradient. But the many many many noisy dots in the picture stay. Here I kindly ask for the next right step

3.) Using the BatchPreprocessing Script with the direct RAW Canon CR2 Files does not work. The Script always stops with an I/O Error and the hint that some file can not be found... So my workaround was to Convert the CR2 Files into FIT Files. Then the Script works until the end. Do I or PI have a bug inside?


Long entry, but I hope you are patient with an freshman but really impressed new PI user.
Thank you and very best regards
Roman

[Luigi]

Roman,

Are you using the Batch Preprocessing script for masters and calibration? If not, it's a real time saver .. you're lucky to be joining the PI Universe now. Why, I remember having to do all the masters/calibration manually in my day ..

If you're still seeing 'hot' pixels after calibration perhaps you need to add 'Cosmetic Correction' into the mix? If they're noise, then a noise-reduction like Multiscale Median Transform would be the next step, I think.

There is a 'sticky' post on DSLR processing in PI, please see this thread:
http://pixinsight.com/forum/index.php?topic=2570.0

[georg.viehoever]

The BatchPreprocessing script is discussed in this thread http://pixinsight.com/forum/index.php?topic=3654.msg30596#msg30596, delivered via the normal PI update mechanism (i.e. no need for a manual install), and in PI available under Script/Batchprocessing.
Georg

[rfriedrich]

Hi guys,
thanks for your reply. Indeed I used the Batch Preprocessing script.
But still the questions stay with debayering or not of the lights and the darks which I feed into the script? Perhaps this question is obsolete - I don't know.
I just search for the possibility to reduce the noise perhaps already before using the script.
Perhaps this is not necessary?
The hints with the wavelet and cosmetic stuff is hard for me because as I wrote I am a beginner.
I checked the links and to be honest the content is a little to high for me. Perhaps you have some newbie instructions for me?
thanks in advance
best regards
Roman

[rfriedrich]

Hi Guys,
I found a thread in this forum (http://pixinsight.com/forum/index.php?topic=4385.0) which describes exactly my problem.
A really noisy image.
My problem is that I can not reproduce the step from the screenshot with the noisy image and the next without the noise.
there is just HT written but i tried and ... failed :-(

perhaps you have any hints for me.

thank you an advance
best regards
Roman