Overexposure?

Questions and answers about processing in StarTools and how to accomplish certain tasks.
mhamburg
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Overexposure?

Post by mhamburg »

This image has been modified in StarTools.
This image has been modified in StarTools.
sized_M1_inprocess.jpg (126.07 KiB) Viewed 7253 times
This is a 13X300s@1600iso shot of M1 (80mm APO Orion refractor) that I am trying to process. Obviously the nebula is overexposed and there is an overall reddish cast to the stars and background (the camera is a modded Canon 40D.). If possible, how do I correct? Thanks.
Michael
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Re: Overexposure?

Post by admin »

Hi,

This one is tough to comment on without the data available. Any chance you could share it so I can have a closer look? Thanks!
Ivo Jager
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mhamburg
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Re: Overexposure?

Post by mhamburg »

I would be more than happy to, Ivo. What would you like exactly?
Michael
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Re: Overexposure?

Post by admin »

mhamburg wrote:I would be more than happy to, Ivo. What would you like exactly?
Michael
Any chance you could share the stacked image (e.g. the FITS or TIFF file you open in StarTools) with me through Dropbox, Google Drive or similar?
Ivo Jager
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mhamburg
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Re: Overexposure?

Post by mhamburg »

I will try as soon as I get the chance.
Michael
ps I sent the fits via DropBox (I think?) :think:
mhamburg
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Re: Overexposure?

Post by mhamburg »

Hi Ivo,
Did you ever get that stack?
Michael
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Re: Overexposure?

Post by admin »

mhamburg wrote:Hi Ivo,
Did you ever get that stack?
Michael
I'm afraid not... :( How did you share it with me? Did you send me a PM or e-mail the link?
Ivo Jager
StarTools creator and astronomy enthusiast
mhamburg
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Joined: Mon Sep 08, 2014 12:40 pm

Re: Overexposure?

Post by mhamburg »

I thought I did via Dropbox, but it obviously didn't work. I will try again.
Michael
mhamburg
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Re: Overexposure?

Post by mhamburg »

I ran the .tif file through StarTools once more and got this result which I think came out better.
Michael
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13x300s@1600iso<br />80mm Orion ED apo
13x300s@1600iso
80mm Orion ED apo
sized_M1_redo_01_11_15.jpg (150.7 KiB) Viewed 7181 times
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Re: Overexposure?

Post by admin »

Thanks, I finally got the data! :D

As a side note, you need to start taking flats! It'll really help improve your images.

To avoid over exposure of the object of interest, use the AutoDev modules' Region Of Interest feature; click & drag a rectangle over (part of) M1 until you're happy with the resulting stretch;
Screenshot-Untitled Window-1.png
Screenshot-Untitled Window-1.png (840.54 KiB) Viewed 7169 times
Decon can be applied and the HDR module's Reveal algorithm may help as well (you may have to tweak the detail size range for very small objects).

Finally, as in every other good work flow, launch the Color module before switching Tracking off. You'll hopefully end up with something likes this (before noise reduction);
Autosave001(1).jpg
Autosave001(1).jpg (374.11 KiB) Viewed 7169 times
Hope this helps!
Ivo Jager
StarTools creator and astronomy enthusiast
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