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Author Topic: noise / moire pattern 5diii long exposure low iso  (Read 1500 times)

edawg

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noise / moire pattern 5diii long exposure low iso
« on: June 02, 2012, 03:24:35 PM »
I am having an issue with some sort of green/magenta noise pattern or moire with my 5d III. Has anyone else noticed this?

I have noticed it at low ISOs with long exposures of particularly blank surfaces lacking detail: shadows, water, etc.

How can I avoid this?

Here is the original:


And with curves adjusted so you can see the issue more clearly:


Turning off Auto Lighting Optimizer actually makes it worse. Images processed in DPP.
« Last Edit: June 02, 2012, 03:45:09 PM by edawg »

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noise / moire pattern 5diii long exposure low iso
« on: June 02, 2012, 03:24:35 PM »

edawg

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Re: noise / moire pattern 5diii long exposure low iso
« Reply #1 on: June 02, 2012, 03:28:15 PM »
EXIF data:

File Name   EDG_4054_1.CR2
Camera Model   Canon EOS 5D Mark III
Firmware   Firmware Version 1.0.7
Shooting Date/Time   6/1/2012 10:15:42 PM
Author   Ed Graham
Owner's Name   
Shooting Mode   Bulb
Tv( Shutter Speed )   150.4
Av( Aperture Value )   11.0
Metering Mode   Evaluative Metering
ISO Speed   200
Auto ISO Speed   OFF
Lens   EF17-40mm f/4L USM
Focal Length   17.0mm
Image Size   5760x3840
Image Quality   RAW
Flash   Off
FE lock   OFF
White Balance Mode   Auto
AF Mode   Manual focusing
Picture Style   Auto
Sharpness   3
Contrast   0
Saturation   0
Color tone   0
Color Space   sRGB
Long exposure noise reduction   Disable
High ISO speed noise reduction   Standard
Highlight tone priority   Disable
Auto Lighting Optimizer   Standard
Peripheral illumination correction   Disable
Chromatic aberration correction   Enable
Dust Delete Data   No
File Size   23176KB
Drive Mode   Single shooting
Live View Shooting   OFF

jrista

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Re: noise / moire pattern 5diii long exposure low iso
« Reply #2 on: June 03, 2012, 04:48:07 PM »
That is not moire, nor is it noise...its posterization. This kind of thing is often the result of image processing and compression, and can be seen frequently in JPEG images less than around 90 quality that have areas of smooth gradient (like a sky.)

I can't be sure what causes that, however I do believe I remember seeing some threads in the past about similar problems with the 5D II as well. I noticed that you have High ISO speed NR enabled... You might want to disable that. You might also want to disable the CA correction. Those are all post-processing effects, and they may be affecting the saved image. I know the Image Quality EXIF value says "RAW", however I am suspicious it might actually be a native-size form of mRAW (a form of YCC encoding, and definitely not an actual RAW format.) To actually apply aberration, peripheral illumination correction, and noise reduction, the output image couldn't be in a true RAW format, and if the data is encoded in some form, then that could be the source of the posterization.

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Re: noise / moire pattern 5diii long exposure low iso
« Reply #2 on: June 03, 2012, 04:48:07 PM »