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Author Topic: Maze/mosaic patterns in Phase One files  (Read 1680 times)

skimasks

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Maze/mosaic patterns in Phase One files
« on: August 28, 2010, 01:10:46 am »

I just shot a few shots with my new/used P25+ and I noticed there were light leaks in my bellows (I am shooting it attached to a horseman view camera with a 210mm caltar lens. When opening the files on my computer (in PS CS3) I found that there were maze shaped patterns on the image, especially where the light leak occurred. I had seen this before with one of sony's dslrs but never on a digital back. When opening the same file in Capture One Pro it seems the file's mosaic pattern either was
a) not there anymore
b) was smoothed over/affected by slight posterization.

Does anyone know what causes this/where I could find out more about the pattern, what causes it, how to remedy?

ondebanks

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Re: Maze/mosaic patterns in Phase One files
« Reply #1 on: August 28, 2010, 07:30:56 pm »

Welcome to the forum, ski' !

Could you post an image of the problem? Might help us to diagnose it.
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skimasks

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Re: Maze/mosaic patterns in Phase One files
« Reply #2 on: August 28, 2010, 08:16:33 pm »

Sure thing
this is a 400 percent blowup.

Doug Peterson

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Re: Maze/mosaic patterns in Phase One files
« Reply #3 on: August 28, 2010, 09:53:33 pm »

This looks similar to "pattern noise" caused by having an extreme highlight somewhere within the image.

Capture One automatically corrects for it with minimal artifacts of the process of removal.
« Last Edit: August 29, 2010, 09:55:35 am by dougpetersonci »
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ondebanks

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Re: Maze/mosaic patterns in Phase One files
« Reply #4 on: August 29, 2010, 08:22:08 am »

Hmm. That doesn't look like any pattern noise I've ever seen from a CCD. What's the underlying physical cause of the "maziness", Doug?
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deejjjaaaa

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Re: Maze/mosaic patterns in Phase One files
« Reply #5 on: August 29, 2010, 09:46:45 am »

That doesn't look like any pattern noise
this maze pattern is a demosaicing bug.
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Graeme Nattress

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Re: Maze/mosaic patterns in Phase One files
« Reply #6 on: August 29, 2010, 09:49:55 am »

Yes, it's a demosaicing artifact where the algorithm has difficulty coping with edge interpolation on flat, but slightly noisy areas, getting confused and producing a maze-like pattern. It sounds like better raw software is needed for these images - one with a more advanced demosaicing algorithm.

Graeme
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skimasks

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Re: Maze/mosaic patterns in Phase One files
« Reply #7 on: August 29, 2010, 04:36:59 pm »

Thanks guys, this gives me a solid jumping off ground for researching how/why this happens! I'll just have to update my ACR..or just use C1Pro to process before post production.

I didn't realize you posted here Graeme, I usually read your posts on Red User. :)

Graeme Nattress

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Re: Maze/mosaic patterns in Phase One files
« Reply #8 on: August 29, 2010, 05:13:22 pm »

I think I was posting here before REDUser even existed.... :-)

Graeme
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