Problem with DeBayer of Light Frame

[niteman1946]

Using a modified XSi camera and capturing images of NGC3628.  My skies suffer from quite a bit of light pollution, so I am using a skyglow filter and over-exposing somewhat.

I run into a problem while following the workflow of this thread:  http://pixinsight.com/forum/index.php?topic=2570.msg19019#msg19019

All is OK through my calibration of the Light Frames.  But when I execute the DeBayer operation, each sub turns white and the few stars that had been in the image prior to DeBayer are now gone.  Star Alignment fails as a result.

The subs leading up to the Debayer operation look allright.  Somewhat pink and light, but containing stars and just a hint of NGC3628.  And I can skip the Debayer operation and Star Align the non debayered images.  For some reason, Debayer is wiping the image clean.


Mark

[Cleon_Wells]

Mark, try to debayer a couple of uncalibrated lights and see if the problem goes away.
The Calibration process could be your problem.
Cleon

[niteman1946]

Thanks for the suggestion, Cleon.

Yes, when I deBayer a non-calibrated CR2 file, I get a dark image of the actual object.  And this can be auto-stretched into something recognizable.

Here are some things I've tried over the last several hours of troubleshooting.
1.  Stumbled on the fact that the Format Explorer/DSLR_RAW settings had gone back to factory default.  Reset these, but it did not help.
2.  Went back 3 times to the Calibration and Integration of the Dark frames before then continuing onto Light calibration, deBayer and then failing at Star Alignment (that is a lot of time).

My work flow is to create the Master Bias, Master Flat, Master Dark, and then calibrate them into my lights (images).  I have successfully used the Master Bias and Master Flat on a previous image (did not change my setup).  Currently, I'm collecting my Darks at the conclusion of the image session.  So these and the Lights are what gets processed each time.

I had followed the same process with success on a previous object, so this has really got me stumped.


Mark

[Cleon_Wells]

Mark, read through this thread I started on Calibration,

http://pixinsight.com/forum/index.php?topic=2411.0

I got some good input from Georg and Zerro1, note Zerro1’s idea of using a iso-100 Flat.
Cleon

[niteman1946]

Thanks again Cleon for directions to your thread.  There's so much to read on this and every bit helps.

I've created a cookbook for myself on the processing steps, mainly because it is complicated, ... and I suffer from CRS.  So while using the cookbook, I'm pretty sure that my routine is consistant.
I cleaned out some disk space and rebooted my computer a couple of times, and voila'.  PI appears to be kinda working properly now.  If the problem was memory, it would have been nice for PI to give me a hint rather than just provide bizarre results.
My wife said this morning (after my having spent quite a bit of time at the keyboard) that I had yet to say anything nice about this software. 
Still trying.....

Thanks again.

Mark

P.S.  I have followed the ISO100 vs Image speed discussion, and decided early-on to go with the image speed.  It's not a hassle.

[Cleon_Wells]

Mark, yes there’s a lot of steps in the Calibration Process and it’s easy, to easy to get it wrong…. To reduce the frustration that  Calibrating  can create  I’ll Calibrate one CR2 sub, get a _c.fit sub (remember when you Calibrate a raw/CR2 file you will get a _c.fit file that is built from settings in the DSLR_RAW preference tab) then BatchDebayer it, do a quick STF to see if I’m in the ballpark. I would suggest you start by not Calibrating your Master Dark and Flat sub files before you integrate them, just check the cal box in the Master Dark and Flat section, this will eliminate possible problems of Calibrating the Master Calibration  files wrong.
I tried recalibrating my M2 subs  with MONO MASTER Calibration files the other day and got this image of M42 the last image, The Master MONO BIAS is 20 100iso@1/4000, the MASTER MONO DARK  is 10 iso400@90sec, the MASTER MONO FLAT is 10 iso100@1/1000, none of the sub  D or F files where Calibrated before integration. This image is not that good but it got a wow out of my wife and I am getting dark levels 1/3 the amount compared to the RGB MASTER B,D, F calibrated  light subs. This image is only 433-sec @ iso400 T1i Hap Mod on a 10”RC.

http://www.astronomybycleon.com/files/page0-1003-full.html

Cleon

[niteman1946]

Cleon, excellent M42.  I can see how your wife was impressed.

I took your advice and passed on the calibration of the master flats and darks.  Calibrated them during the Master Light calibration, and the image looked so much better.

Thanks again for your help.

Mark

[Cleon_Wells]

Mark , glad I could help.
This M42 image is the result of my skillful manipulation of all the subs, using MonoChrome Calibration Master files and the DLP method.
DLP stands for “Dumb Luck Processing”, which definitely helped on this image. LOL
I  still don’t know way the MonoChrome Calibration Masters helped improve this image.
Cleon