Author Topic: Aliasing with RAW  (Read 27428 times)

IliasG

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Re: Aliasing with RAW
« Reply #25 on: June 12, 2013, 03:15:38 AM »
Not sure what is happening here but normally if there is no skipping we should take less noise after bining pixels which is not the case according to measures on Black frames ..

http://www.magiclantern.fm/forum/index.php?topic=5609.msg39410#msg39410

Kim.dh

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Re: Aliasing with RAW
« Reply #26 on: June 22, 2013, 04:15:56 PM »
I am having a bad case of noise that I believe is caused by aliasing. This video is shot at ISO 100 180 degree shutter, 1280x640@15 fps:


Notice on the rocks you can see some "pixie dust" noise/grain. Does anyone know the cause of this and is it possible to fix in post?

dariSSight#1

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Re: Aliasing with RAW
« Reply #27 on: June 22, 2013, 06:08:33 PM »
I hate to say it dude but the moire and aliasing on that shot is very obvious to me. On the fence between the trees on the left, color patterns all over the distant tree and all the weird coloring on the darker of the two rooftops.

Sorry man - don't mean to be negative, just saying what I see.


I seen this forum thread before but I don't think I soak it in. Reddeercity Post is very vital for the point of Aliasing and Moire fears, I took a closer look at his video after reading the thread and you can see he was correct Aliasing can be seen in the small low Res window but if you open it to full screen and even more pick the 1080p or Original format option it clears up greatly for presentation (beautiful), that's scratching the surface of filming in RAW and Upscaling. Thanks again for the revisit to the thread because it help drill the option of line skipping, Moire and Aliasing problem solving into my head.

mageye

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Re: Aliasing with RAW
« Reply #28 on: June 22, 2013, 09:43:22 PM »
I am going to link something I found a long, long, time ago. I never tested it myself but intended to at some point. My strategy for dealing with moire is generally to avoid things that are known sources of it. :-\

http://colorbyjorg.wordpress.com/plugins/

I would like to think that it's highly effective and kills any sign of moire. I do, at least, have hope (and optimism :) ).
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Kim.dh

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Re: Aliasing with RAW
« Reply #29 on: June 22, 2013, 10:57:52 PM »
I am going to link something I found a long, long, time ago. I never tested it myself but intended to at some point. My strategy for dealing with moire is generally to avoid things that are known sources of it. :-\

http://colorbyjorg.wordpress.com/plugins/

I would like to think that it's highly effective and kills any sign of moire. I do, at least, have hope (and optimism :) ).
Looks great, but I am on a windows system. Do you know of any similar plugins/filters for After Effects/Premiere?

mageye

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Re: Aliasing with RAW
« Reply #30 on: June 22, 2013, 11:01:54 PM »
I don't know of any for Windows unfortunately. I found this one a long time ago and forgot that it was a plugin for Final Cut Pro and of course that only runs on the mac.

Sorry. :(
5DMKII | 500D | KOMPUTERBAY 32GB Professional 1000x |Canon EF 50mm f/1.8 II | Samyang 35mm f/1.4 ED AS UMC | Canon EF 75-300mm f/4-5.6 III | Zoom H2 (4CH. audio recorder) | Mac OS X 10.9.2 | Photoshop CC | After Effects CC | Final Cut Pro 7

Nickbibs

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Re: Aliasing with RAW
« Reply #31 on: June 23, 2013, 03:20:31 PM »
Good example of how bad it is on the 60D!

Kim.dh

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Re: Aliasing with RAW
« Reply #32 on: June 24, 2013, 08:50:25 PM »
I was able to get rid of most of the micro-moire noise by using Photo Ninja to convert to TIFF; Using the "Enhanced" demosaicing algorithm and the Noise Ninja 3.0 Color Noise reduction, which reduced the noise considerably, and then using Magic Bullet denoiser II in Premiere.

noisyboy

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Re: Aliasing with RAW
« Reply #33 on: June 24, 2013, 09:17:01 PM »
I am going to link something I found a long, long, time ago. I never tested it myself but intended to at some point. My strategy for dealing with moire is generally to avoid things that are known sources of it. :-\

http://colorbyjorg.wordpress.com/plugins/

I would like to think that it's highly effective and kills any sign of moire. I do, at least, have hope (and optimism :) ).

You can achieve the same results by using Smoothkit by RE:Vision and applying a Gaussian to only the chroma. Works really well actually :)

crash-film

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Re: Aliasing with RAW
« Reply #34 on: June 25, 2013, 03:31:48 AM »
For all of you using ACR:

for static images you can paint out moire/aliasing. apply a mask in ACR paint over the moire/aliasing infected areas (fine building structures etc.) and find the slider named "moire reduction". depending on the amount of moire apply a value of about 20 to 30 (+/-). use it carefully since it seems to blur the affected color channels and you loose a lot of saturation but not contrast, giving you a sharper yet less aliased image.

for moving images or moire all over the image just set a big paint stroke over the whole image and adjust as desired.
the effect is stunning. but you lose of course a lot of color information and the image becomes desaturated.
but at least it could be a way to solve some specific shots.

just discovered this and didnĀ“t really test it.

Kim.dh

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Re: Aliasing with RAW
« Reply #35 on: June 25, 2013, 04:31:45 AM »
Tried various AE plugins, and so far I found the best results using one pass of "Temporal" noise reduction with RE:Vision Denoise followed by a pass of Magic Bullet Denoiser.


kgv5

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Re: Aliasing with RAW
« Reply #36 on: June 26, 2013, 12:26:54 PM »
Here you have some raw DNG's for comparing the picture with and without mosaic engineering anti aliasing / moire filter VAF-6D.

http://www.magiclantern.fm/forum/index.php?topic=6577.msg55134;topicseen#msg55134
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cthornhill

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Re: Aliasing with RAW
« Reply #37 on: June 27, 2013, 06:49:22 PM »
Great posts, this is very helpful. I did some tests on mu 60D with and without the VAF-60D, but did not get great results with raw at lower resolutions. My ISO was very high for this quick test, and I need to repeat it with lighting to see how that might impact the tests. I did see better results the higher the resolution went, but not as good as those where I used full HD in H264 (where the AVF-60 fixed the issues super well). My test was a nasty one - a herringbone fabric, so it was 'asking for trouble'...anyway, I a happy with the AVF myself, as it is very useful on H264 for me, and I expect to get some benefit at least in raw, depending on the way I shoot. I really appreciate hearing what others see, as it helps me get a better idea what to expect, especially if I eventually change camera bodies. Thanks for the hard work.

POSTSCRIPT - I reviewed my data and found more correction than I originally saw when I looked closer. My estimation is that some subjects are easier to correct than others. I think that the VAF for each camera is only as strong as needed for what they tested for - and the 60D in raw is a LOT sharper, so maybe it could stand a stronger filter for raw work, but mine appears to help even if it is not perfect in all situations.