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Old 29-04-2018, 04:56 PM
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Gravity does not Suck

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Shooting by the light of the Moon.

Once I never bothered but given the weather my current approach is if its clear I am going for it even if its full Moon.

So thinking about things I wondered this...

Could you take a frame or multiple frames of a region of the sky with few stars and perhaps out of focus and use that frame subtracting it from a stack of your light frames...maybe by introducing as a flat frame in DSS or maybe someway in Photos Shop Elements or Star Tools ( I now have both of these ..no pixinsite..its not the money its that I need some simpler tools for the present.
Or even creating a blanl light sheet and subtracting that...

So is something like I suggest possible?

Alex
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Old 29-04-2018, 05:49 PM
Imme (Jon)
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Originally Posted by xelasnave View Post
Once I never bothered but given the weather my current approach is if its clear I am going for it even if its full Moon.

So thinking about things I wondered this...

Could you take a frame or multiple frames of a region of the sky with few stars and perhaps out of focus and use that frame subtracting it from a stack of your light frames...maybe by introducing as a flat frame in DSS or maybe someway in Photos Shop Elements or Star Tools ( I now have both of these ..no pixinsite..its not the money its that I need some simpler tools for the present.
Or even creating a blanl light sheet and subtracting that...

So is something like I suggest possible?

Alex
Does your brain ever stop ticking Alex?

Love your posts

In answer to your question.......no idea
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Old 29-04-2018, 06:17 PM
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Gravity does not Suck

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Originally Posted by Imme View Post
Does your brain ever stop ticking Alex?

Love your posts

In answer to your question.......no idea
Thank you I am happy , for your sake , that you enjoy my posts.
I get great pleasure to think I can cheer someone up so thank you for the encouragement.
Dont you like to be the only one who has not grumped and growled at the poor under rewarded shop assistent or not be the one to end the life of some inoccent little insect.

And I would not say my brain ticks as that implies and pits up vissions of a well working clock and unfortunately I am not that predictable or reliable.
Thank again.
Alex
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Old 29-04-2018, 08:52 PM
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It dawned on my my idea could not work...
Alex
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Old 30-04-2018, 09:05 PM
Wavytone
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Alex it sounds like you're trying to re-create the HDR effect or "fractional differentiation" to enhance detail and obtain an extended dynamic range
http://staff.polito.it/amelia.sparav...actool-web.htm
https://arxiv.org/pdf/0910.4243.pdf
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Old 01-05-2018, 01:26 AM
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Alex, I think that your suggested method is just a background subtraction which is commonly done during the image processing stage. Normally you would not take another image but use areas without nebulosity and without stars (or in between stars) in the existing image. This way the background gradients can also be removed.

The main problem with subtracting background from a different part of the sky is that the background and hence the background gradients would be different and can make things worse.

Apart from the gradients the main problem for imaging while the moon is up is that the weaker signals will get swamped by the increased background and cannot be distinguished from the background noise any more. That's why the dark skies work the best.
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Old 01-05-2018, 01:43 PM
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ZeroID (Brent)
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I know where Alex is coming from, you have to take advantage of whatever clear skies you can get and they have been few and far between lately.
I just find targets in the South, away from the light of the moon. Used to work reasonably ok with the Canon. Shorter exposures, a bit more processing effort. I'm used to trying to deal with a lot of LP from our CBD so the moon is just another thing to manage. Or you can take pix of it, which I have been known to do. Currently my efforts have been all quick peeks at the sun between the clouds, evenings have been windy, wet and a bit wild.
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Old 01-05-2018, 03:11 PM
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Thanks to all for the input.
I have decided to forget about even thinking about imaging dark sky objects in Moon light but perhaps I will drag out my old 150 mm refractor and take photos of the Moon.
The weather has made me desparate.
Thanks everybody.
Wavy I enjoyed your link and it taxed me frankly.

Alex
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