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Blue blotches - lens flare or what?

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#1 khobar

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Posted 11 January 2019 - 11:52 AM

I've noticed some blue blotches on my pics and am wondering what they are. Using an 80mm ES80 APO with a modded Nikon D5100, a ES field flattener and Orion imaging LPF. They've been present in my B33/Flame, M42, and M45 at least. I thought there was just three but when I looked at my M45 from last night there seemed to be a whole lot more.

 

These were stacked in DSS, adjustments *applied* just so I could bring out what I was talking about. There are some dark spots, too, probably just dust. But the blotches - just dirt? Pin holes in the filter? Something else? Thanks.

 

Just off M42:

M42-blue-blotches-small.jpg

 

M45:

m45-blue-blotches-small.jpg



#2 khobar

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Posted 11 January 2019 - 12:22 PM

As a follow up, here's a shot of NGC2467 using same equipment, same night, etc. There are fewer subs (6) however.

 

I don't *think* I see the blotches.

 

 

Attached Thumbnails

  • NGC267-small.jpg


#3 einarin

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Posted 11 January 2019 - 12:36 PM

Reflection from brighter stars.

You could try without field flattener.


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#4 OldManSky

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Posted 11 January 2019 - 03:44 PM

Yep, reflections from stars.  I'd blame the LP filter before the FF though...they're usually the culprit.



#5 bill5wjw

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Posted 11 January 2019 - 04:31 PM

Are you using flat frames in your stacking process? If so, then as einarin said above, remove the flattener, and try again.

I also had a problem with a reflection in this region of the sky and it turned out that a threaded adapter I was using was causing reflections that looked like arcs. I spray painted the inside of this adapter with flat black paint and now there are no more reflections.



#6 khobar

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Posted 11 January 2019 - 11:17 PM

Very interesting!

 

I am using flats.

 

It was supposed to be cloudy tonight, but I was able to get about an hour in before it clouded over and can confirm without the FF I can see no blotches, blue or otherwise, at least not with M45.

 

So, what now?




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