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Old 26-04-2018, 10:23 AM
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Mitigating FPN

I dither, all the time. MaxIM does it really well.

This has helped in the past ENORMOUSLY at mitigating most, if not all of the FPN from my images. Yet, the other night, my dithered images of Corona Australis show the horrid diagonal FPN again.

Should dithering be MORE aggressive for the dark and dusty compared to bright H-a etc? I was really surprised to see the FPN in the image to be honest, only really noticeable through the dark lane.

Suggestions? Just larger scale dithering?
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Old 26-04-2018, 12:54 PM
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Nikolas (Nik)
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Silly question
FPN?
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Old 26-04-2018, 12:56 PM
Imme (Jon)
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Silly question
FPN?
Friday Pub Noise

.....also known as 'the shakes'
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Old 26-04-2018, 02:36 PM
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That too, but also know as Fixed Pattern Noise.
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Old 26-04-2018, 03:14 PM
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That too, but also know as Fixed Pattern Noise.
Isn't that what is in Turnbulls NBN?.......oh wait, that's FTTN...Fibre That only Turnbull Needs
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Old 26-04-2018, 03:27 PM
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Friday Pub Noise

.....also known as 'the shakes'
That explains the dithering then
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Old 26-04-2018, 03:54 PM
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Isn't that what is in Turnbulls NBN?.......oh wait, that's FTTN...Fibre That only Turnbull Needs


More like Failure To Telecommunicate Now.

Now, back to the question: when is it beer o'clock?
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Old 26-04-2018, 06:24 PM
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ZeroID (Brent)
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This has to be the most confused thread I have ever come across on IIS



When is Beer O'clock anyway ?
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Old 26-04-2018, 06:36 PM
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This thread follows a fixed pattern of noise.
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Old 01-05-2018, 11:00 AM
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Hi Lewis,

Your question wasn't answered, but fixed pattern noise are like dust bunnies, i.e they are fixed in the same place in each sub exposure.

You need a good master flat to eliminate them.

Cheers
Bill
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Old 01-05-2018, 07:37 PM
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Been doing some reading, and flats DON'T mitigate FPN, ONLY dithering, and usually quite aggressive and randomised dithering of more than 5 pixels.

So, I upped my dithering settings. Will test it next time out.
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Old 01-05-2018, 07:49 PM
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Depends on whose bible we read, I got my information from a white paper written by Richard Crisp (don't know who he is) in 2014.
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Old 01-05-2018, 08:11 PM
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I got my information from a white paper written by Richard Crisp (don't know who he is) in 2014.
Richard designs semiconductors as a day job and knows shedloads about sensor technology and is an active imager. You'd want to be very certain of your facts to argue with him
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Old 01-05-2018, 08:13 PM
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Crispy....

I'll make a buzzillion more flats and make a new Master...
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