PixInsight Forum (historical)

PixInsight => General => Off-topic => Topic started by: Alejandro Tombolini on 2011 February 09 16:35:16

Title: DSRL EXTREME NOISE
Post by: Alejandro Tombolini on 2011 February 09 16:35:16
Hello People, it is summer in Argentina and I took some picture at 30ºC (86ºF) and the
consequence was a new noise in the CANON Xsi (450).

Attached you can see the following crops:

1) Individual frame without calibration
2) Calibrated frame
3) Integration (15 frames)
4) Final image (Here complete final image)

The red, blue and green hot pixels are the usual ones I have to deal with, but the vertical lines in the background
are new. (Only with 10 minutes pictures at 30ºC)

Calibration worked well with hot pixels but not with lines.

In the integration there is some "interference". I think it could be because I integrate
two set of images in different position...¿?

In the final image most of the vertical lines remain.

Does anybody know how to eliminate these lines?

 
JPG
http://www.4shared.com/photo/Q6bYnN5R/Calibrated_Individual_Frame.html
http://www.4shared.com/photo/4i0uXtY0/Final_image.html
http://www.4shared.com/photo/nQ9Rjc4A/Integration_of_15_Calibrated_F.html
http://www.4shared.com/photo/7M32OWQc/Uncalibrated_Individual_Frame.html

FIT
http://www.4shared.com/file/2jbDBwuF/Calibrated_Individual_Frame.html
http://www.4shared.com/file/qhYnDIWF/Final_image.html
http://www.4shared.com/file/rlIzzEZE/Integration_of_15_Calibrated_F.html
http://www.4shared.com/file/dl6EGWKa/Uncalibrated_Individual_Frame.html

Processed image:
http://proxima-sur.blogspot.com/
Title: Re: DSRL EXTREME NOISE
Post by: Nocturnal on 2011 February 09 16:37:46
'Shudder'. That looks miserable. One of the reasons I skipped DSLRs and went straight to a cooled CCD. I like fixing problems but that looks bad. I hope you find a solution soon.
Title: Re: DSRL EXTREME NOISE
Post by: Alejandro Tombolini on 2011 February 09 16:53:31
Yes!, good solution, but it will be next year. For know it is a good set up for learning PixInsight :)
Title: Re: DSRL EXTREME NOISE
Post by: Nocturnal on 2011 February 09 16:57:00
Sorry, I did not mean to suggest getting a cooled CCD is a real solution. You're looking to make your DSLR work better. I know little about those things, sorry. I do know that 30C is very warm and will make it hard for a DSLR to perform well.
Title: Re: DSRL EXTREME NOISE
Post by: Redshift on 2011 February 10 00:38:37
Alejandro,

Did you remember to debayer the individual subs? I think that may be the problem.

Regards
Dave
Title: Re: DSRL EXTREME NOISE
Post by: Alejandro Tombolini on 2011 February 10 15:31:57
No, I didn't. In fact It is samething that I am not doing yet. Let me learn a little bit about that and try again.
Title: Re: DSRL EXTREME NOISE
Post by: Nocturnal on 2011 February 10 16:38:39
Ah. Subs need to be calibrated and debayered before registering and stacking.
Title: Re: DSRL EXTREME NOISE
Post by: Enzo De Bernardini on 2011 February 10 16:44:52
Ah. Subs need to be calibrated and debayered before registering and stacking.

I think that Alejandro open all subs already debayerized, and this linear pattern are in the subs also. Must have something to do with the heat I guess...but, are removable?

Enzo.
Title: Re: DSRL EXTREME NOISE
Post by: Cleon_Wells on 2011 February 11 10:46:43
Alejandro,  goto DSLR_RAW workflow , here you'll find many links to posts that explain the basic DSLR workflow in PI , this was assembled by Astropixel..
Goto General/Tutorials/DSLR_RAW workflow.
Cleon
Title: Re: DSRL EXTREME NOISE
Post by: Alejandro Tombolini on 2011 March 22 14:23:45
Hola,

Volviendo sobre este tema...

Ante todo mi agradecimiento a Enzo por desarrollar un script para un caso tan particular como éste. http://pixinsight.com/forum/index.php?topic=2956.msg20267#msg20267

En el siguiente link está el detalle de los pasos seguidos para eliminar el ruido lineal de estas fotos.

Mis disculpas a los que leen inglés si algo no esta bien redactado.

Version en Castellano: http://proxima-sur-procesamiento.blogspot.com/2011/03/patron-de-ruido-lineal.html



Hi,

Coming back to this topic...

First of all my gratitude to Enzo for developing a script for a very particular case as this one. http://pixinsight.com/forum/index.php?topic=2956.msg20267#msg20267
 
In the following link are detailed the steps to eliminate the linear noise of these photos.

My excuses to those who read English if anything is not written well.

English Version: http://proxima-sur-processing.blogspot.com/2011/03/linear-noise-pattern.html


Alejandro.
Title: Re: DSRL EXTREME NOISE
Post by: georg.viehoever on 2011 March 22 15:11:31
Wow, I have never seen this kind of pattern with my Canon EOS 40D. I wonder what the cause of this problem is. My first thought was incorrect debayering, but I am sure you checked that,

Anyway: the script does wonders to your data. Congratulations to both of you.

Georg