PixInsight Forum

PixInsight => General => Topic started by: rikkimantha on 2013 November 03 08:26:28

Title: Noob need's opinions.
Post by: rikkimantha on 2013 November 03 08:26:28
Hi. This is my first post ever anywhere.
I need and opinion on what can cause my photos to have certain issues.
I am a noob. Started taking photo's this Sept. For some reason my
photo's suck. They are half green and half red and the very bright stars have
all kinds of donuts around them. My telescope is a SkyWatcher 8"
Quattro CF , camera is a Canon T3 with Baader MPCC and Orion Skyglow
AP filter. Any suggestions that i can try to correct these issues would be very appreciated.
I rarely get to image because of the weather. Oct was complete bust. I dont want to waste all
of my sessions freezing outside troubleshooting for something obvious to a pro.
I have included and attachment image and a link to the original Pixinsight calibrated fits files.


Thank You
Title: Re: Noob need's opinions.
Post by: Zocky on 2013 November 03 12:46:23
Hi, maybe your issue is due to LP? Or you have done something wrong in your work flow?
Here is your image. First I `ve applied DBE, then SCNR, then histogram was stretched, and finally I did some CurvesTransformation.
Title: Re: Noob need's opinions.
Post by: Geoff on 2013 November 03 22:59:03
The halos around the bright stars look like internal reflections to me--try imaging without the MPCC and the AP filter.  Remove one then put it back and remove the other. Then try removing both.  See if any of these configurations removes the halo problem.
Title: Re: Noob need's opinions.
Post by: papaf on 2013 November 03 23:10:17
I've seen these kind of gradients before and they were coming from LP filters of lowish quality. Orion products are cheap but, yeah, you get what you buy for...
Only filter that never gave me any problem it's been the IDAS. Costly, though.
I would try removing the filter as a first move.
Title: Re: Noob need's opinions.
Post by: rikkimantha on 2013 November 05 07:34:51
Thank's for the answers. I will have no weather it seems for a while so i will try to duplicate the problems with my artificial star.
If i can then i could test with and without MPCC and filter and go from there. I am more worried about the reflections, Pixinsight
takes care of the red and green tint in the image. If the filter is the problem i will try to figure out what model of idas filter i need.
From now on i will try to buy better quality instead of buying twice. 
Title: Re: Noob need's opinions.
Post by: rikkimantha on 2013 November 05 17:45:28
Did the tests. I think it is the camera because i get the same result without MPCC and Filter on the newt and when i tested on and SCT i get simular results. I guess i need a new camera.
Title: Re: Noob need's opinions.
Post by: jkmorse on 2013 November 05 23:28:26
Don't give up yet.  To get the stars under a bit more control you can try using the Morphological Transform tool.  It works great after you have stretched your image to tighten up your stars.  Just make sure you use a star mask so the only thing you are affecting is the stars.

Also, it could be as simple as needing to get you colors properly aligned.  To do that, use the Histogram Transform tool, use a preview and see what your histogram looks like for your RGB image.  What you are likely to see is that the colors are misaligned.  The way to fix that is to look at the color that is most to the left (most likely the blue if you have green and red halos).  click on the other colors, one at a time and adjust the histogram to bring all the colors intop line on the left side.

Other things you can try are the background neutralization and color calibration tools as well as the SCNR tool to remove green tints.  Most of these tools have documentation that help explain how they work (you can get the documentation by clicking on the little symbol near the bottom right side of each tool that looks like a little page with a folded edge). 

In case it helps, I am attaching the latest version of my workflow and tool tips cribsheet that may give you some ideas too.

Best of luck,


Good luck,

Title: Re: Noob need's opinions.
Post by: rikkimantha on 2013 November 09 12:43:47
Fixed the camera reflections issue by removing the 2 glass filters in front on the chip in the camera.
Now my artificial star has no halos. Cant wait to get weather for a real dso test.

Thank's for the help