Reflection on Horsehead Nebula - How to mitigate?

Celestron NexStar Evolution Acquisition Deep Sky Barnard Objects Artifacts
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Jean-David Gadina avatar
Jean-David Gadina avatar
I recently took pictures of the Horsehead Nebula for the first time and noticed a weird reflection on all my subs.
It was visible in NINA, but I did not try to investigate, as it was the first clear night in a while, and I was eager to take some pictures.

I know there are many topics regarding reflections, but I still have a few questions, as this is the first time I have had a reflection like this.

Is such a reflection caused by Alnitak, which is out of frame but close?
What could I have done to mitigate it?
Is there anything I can do when stacking my subs to remove it, or does it all come to post-processing?

The pictures were taken using a Celestron Nexstar Evolution 6 with a .063 reducer and aluminum dew shield.

Engaging
Dan Brown avatar
Dan Brown avatar
Alnitak is a bitch. Short of changing your imaging equipment you will have to deal with it. First and easy is to make a starless version of your image and attack the reflection with cloning. If you want more fidelity in your image try reframing the shot so the affected area is still in frame but the reflection is in a different area. Combine the unaffected area of the second framing with the original framing. Hope that is understandable. 
Dan
Tony Gondola avatar
Tony Gondola avatar
yup, reflections from a bright star outside the camera field.. SCTs are known for this, especially with reducers. You can crop it out or retouch it out if the area around it isn't too large and diffuse. This area gives everyone problems like this. In general, the simpler the imaging train the better.
Helpful Concise
Jean-David Gadina avatar
Jean-David Gadina avatar
Dan Brown:
Alnitak is a bitch. Short of changing your imaging equipment you will have to deal with it. First and easy is to make a starless version of your image and attack the reflection with cloning. If you want more fidelity in your image try reframing the shot so the affected area is still in frame but the reflection is in a different area. Combine the unaffected area of the second framing with the original framing. Hope that is understandable. 
Dan

Tony Gondola:
yup, reflections from a bright star outside the camera field.. SCTs are known for this, especially with reducers. You can crop it out or retouch it out if the area around it isn't too large and diffuse. This area gives everyone problems like this. In general, the simpler the imaging train the better.

Thanks a lot to both of you for the replies!
I can indeed definitely see more reflections coming from Alnitak in the final image.

I ended up cropping that big one. I'm still quite happy with the result for a first try on this beautiful nebula.

Clear skies!
Well written Respectful Supportive
Tony Gondola avatar
Tony Gondola avatar
Glad you made it work!
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