Yesterday over on Cloudy Nights I posted a question regarding an image I've been putting together of the Soul Nebula. There was a rather large red-ish blur in the picture after I got through with processing it. The fine folks over there believe it's stray light getting into the camera from the viewfinder of my Canon T3i. Here's the thread: http://www.cloudynights.com/topic/55497 ... anomalies/
In the first post of the thread I linked to some images that clearly illustrate the red area I'm seeing. Here's a ZIP file that contains those images: https://dl.dropboxusercontent.com/u/291 ... nomaly.zip (Same one linked to in the first post of the thread.)
I've got the view finder covered with black electrical tape now, but in the mean time, I was hoping to get some help with mitigating the issue in the image, if it's possible. The stacked image is about 7.5 hours of sub exposures, and obviously it would be very painful to lose that.
Here is my best attempt at removing the red blur: http://imgur.com/a/YYB3c
Could I get some more experienced help? I feel as if the boundary between the actual nebula and the dark background is pretty harsh and noticeable. What's a good way to remove the artifact subtly?
Thank you for your help!
EDIT: Occurs to me I didn't post the link to the stacked image. Here it is: https://dl.dropboxusercontent.com/u/291 ... acked1.TIF
Sorry about that!