The effect of light pollution filters on native one-shot color camera white balance

Discussion of using SharpCap for Deep Sky Imaging
mAnKiNd
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The effect of light pollution filters on native one-shot color camera white balance

Post by mAnKiNd » Wed Feb 05, 2020 6:35 am

Hello,

Rather than pasting a large document here and taking up lots of space, I've instead written a report you can access by downloading it here:

https://docs.google.com/document/d/127e ... sp=sharing

I have enabled the can comment function in the document, so please feel free to leave your comments in the actual writeup if you wish to provide any edits or spot any errors in need of corrections. Or leave them here :)

I hope this helps, it was a test I did for my own "finding out", which turned into me writing it up to share with you.

All the best,
Minos

AndyBooth
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Re: The effect of light pollution filters on native one-shot color camera white balance

Post by AndyBooth » Wed Feb 05, 2020 8:44 am

Very interesting indeed.
Thanks.

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turfpit
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Re: The effect of light pollution filters on native one-shot color camera white balance

Post by turfpit » Wed Feb 05, 2020 5:32 pm

A sturdy piece of work Minos. Good to see a systematic investigation and detailed write-up. It will take a couple of reads for me to digest thoroughly.

Dave

mAnKiNd
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Re: The effect of light pollution filters on native one-shot color camera white balance

Post by mAnKiNd » Wed Feb 05, 2020 6:48 pm

Thanks,

I suppose the quick take home message is this graph, which shows how each LP filter affects the %RGB signal intensities for my OSC camera. 0% difference in all three RGB signal intensities would achieve a "theoretically unison" white balance.

It shows how green is still the most intense signal except from the UHC+UV/IR combo, which had an orangey cast (see figure 15 in the write-up above).

None of these LP filters achieved a particularly unison native white balance in this specific test, but some interesting results arose.
Screenshot_20200205-133727.png
Screenshot_20200205-133727.png (390.14 KiB) Viewed 967 times
Cheers
Minos

mAnKiNd
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Re: The effect of light pollution filters on native one-shot color camera white balance

Post by mAnKiNd » Mon Feb 10, 2020 9:10 pm

Thought I'd post the raw screen grabs from all the filters I tested (some are totally non sensical!) for quick reference.

The only filter that achieved native OSC white balance is the ZWO 850nm :lol:

Sorry for all the subsequent posts, I could only fit three pics in each post.

I hope to add more test results in the future.
no filter.png
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Optolong_Clear_Focusing.png
Optolong_Clear_Focusing.png (763.88 KiB) Viewed 891 times
Astronomik_UV_IR_L-3.png
Astronomik_UV_IR_L-3.png (768.21 KiB) Viewed 891 times
Last edited by mAnKiNd on Mon Feb 10, 2020 9:20 pm, edited 3 times in total.

mAnKiNd
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Re: The effect of light pollution filters on native one-shot color camera white balance

Post by mAnKiNd » Mon Feb 10, 2020 9:11 pm

Optolong_Moon___Skyglow.png
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Astronomik_CLS.png
Astronomik_CLS.png (760.13 KiB) Viewed 891 times
Astronomik_CLS_+_Astronomik_UV_IR_L-3.png
Astronomik_CLS_+_Astronomik_UV_IR_L-3.png (769.66 KiB) Viewed 891 times

mAnKiNd
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Re: The effect of light pollution filters on native one-shot color camera white balance

Post by mAnKiNd » Mon Feb 10, 2020 9:12 pm

Astronomik_CLS_CCD.png
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Astronomik_UHC-E.png
Astronomik_UHC-E.png (764.41 KiB) Viewed 891 times
Astronomik_UHC-E_+_Astronomik_UV_IR_L-3.png
Astronomik_UHC-E_+_Astronomik_UV_IR_L-3.png (767.03 KiB) Viewed 891 times
Last edited by mAnKiNd on Mon Feb 10, 2020 9:22 pm, edited 1 time in total.

mAnKiNd
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Re: The effect of light pollution filters on native one-shot color camera white balance

Post by mAnKiNd » Mon Feb 10, 2020 9:13 pm

Astronomik_UHC.png
Astronomik_UHC.png (660.32 KiB) Viewed 891 times
Astronomik_UHC+_Astronomik_UV_IR_L-3.png
Astronomik_UHC+_Astronomik_UV_IR_L-3.png (664.68 KiB) Viewed 891 times
ZWO_850nm_IR.png
ZWO_850nm_IR.png (663.51 KiB) Viewed 891 times

mAnKiNd
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Re: The effect of light pollution filters on native one-shot color camera white balance

Post by mAnKiNd » Mon Feb 10, 2020 9:14 pm

Astronomik_Deep_Sky_R.png
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Astronomik_Deep_Sky_G.png
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Astronomik_Deep_Sky_B.png
Astronomik_Deep_Sky_B.png (634.94 KiB) Viewed 890 times

mAnKiNd
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Re: The effect of light pollution filters on native one-shot color camera white balance

Post by mAnKiNd » Mon Feb 10, 2020 9:15 pm

Astronomik_H-beta_12nm_CCD.png
Astronomik_H-beta_12nm_CCD.png (748.81 KiB) Viewed 798 times
Optolong_H-beta_25nm.png
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Optolong_Oiii_25nm.png
Optolong_Oiii_25nm.png (655.57 KiB) Viewed 890 times
Last edited by mAnKiNd on Sat Mar 07, 2020 7:26 pm, edited 1 time in total.

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