2 Replies Latest reply: Mar 8, 2013 6:14 AM by mhbc
mhbc Level 1 (0 points)

General info:


System engineer, Software Hardware suport, Unix 20years, OS X 7 years.

iMac 10.7.5 2.5 Ghz i5 : Graphic card AMD Radeon HD 6750M 512 MB


Until the other day I have had no problems reviewing RAW files imported from any camera - Sony Nex - Panasonic G3 or Canon G1X onto my system nor with Preview nor Aperture.


But one RAW file of long exposure shows up 'Green' in Preview 5.5.3, Core Image, iPhoto & Aperture 3.4.3. Nothing wrong with the jpg file just this one RAW file. 


Using Canon's Digital Photo Professional both files are ok. The RAW file being similar to the jpg file. ImageBrowser also no problem.


Summary :


Canon Digital Photo Professional & ImageBrowser can handle this file. Apple programs can not?


Trying to adjust using any of the tools provided by Aperture, Core Image, iPhoto, Preview fail.

So why the green?

Other long exposure - but not so long - are ok. I took this night shot in preparation of the Comet thats due in 10 days from now. The last thing I need is green only RAW files when reviewing with Aperture.


Any one else have this problem?

  • Kirby Krieger Level 6 (12,510 points)

    Since Canon and only Canon can handle the file (as best we know), I suspect they have baked something into the RAW that violates their own file definition, and have written their own RAW converters to handle this but have not shared it.  Since this happens with exposures longer than some still un-specific duration, I would look for an in-camera setting that affects long exposures.  Does your camera have any?  The one that comes to mind is some kind of automatic noise reduction for long exposures.


    Other than that nothing comes to mind.  Sorry.

  • mhbc Level 1 (0 points)


    Thank you for responding so quickly & your suggestions therein. I apologise for the delay but I have been trying to get some scope on this problem.

    Could be that Canon DPP app handles the long exposure by using the ITU-R BT.709 conversion.

    I ran a scan for ITU-R BT.709 in the /Applications dir & it showed up in /Canon Utilities/Canon MOV Encoder/ …….

    also in /System dir




    ./Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vImage.framework /Versions/A/Headers/Transform.h

    I think a simple short cut to resolving how Apple handles sYCC CR2 information is for someone to try out Final Cut Pro X & see if the problem occurs there.


    The following makes interesting reading :


    Canon CR2 specs


    Canon CR2 files sYCC



    ITU-R BT.709 conversion

    A different form of Y′CbCr is specified in the ITU-R BT.709 standard, primarily for HDTV use. The newer form is also used in some computer-display oriented applications. In this case, the values of Kb and Kr differ, but the formulas for using them are the same. For ITU-R BT.709, the constants are:

    Kb = 0.0722

    Kr = 0.2126


    Exif info


    Aperture Value: 5.312

    Color Space: sRGB

    Components Configuration: 1, 2, 3, 0

    Compressed Bits Per Pixel: 3

    Custom Rendered: Normal process

    Date Time Digitized: 2013:03:05 03:35:40

    Date Time Original: 2013:03:05 03:35:40

    Digital Zoom Ratio: 1

    Exif Version: 2.3

    Exposure Bias Value: 0

    Exposure Mode: Manual exposure

    Exposure Program: Manual

    Exposure Time: 40

    File Source: DSC

    Flash: Flash did not fire, compulsory flash mode

    FlashPix Version: 1.0

    FNumber: 6.3

    Focal Length: 17.505

    Focal Plane Resolution Unit: inches

    Focal Plane X Resolution: 5,905.021

    Focal Plane Y Resolution: 5,902.351

    ISO Speed Ratings: 800

    Max Aperture Value: 3.625

    Metering Mode: Pattern

    Pixel X Dimension: 4,352

    Pixel Y Dimension: 3,264

    Scene Capture Type: Standard

    Sensing Method: One-chip color area sensor

    Shutter Speed Value: -5.312

    White Balance: Auto white balance

    AFInfo: 0.4100414, 0.4096201, 0.1799173, 0.1807598, n

    Firmware: Firmware Version 1.00

    Flash Compensation: 0

    Focus Mode: 0

    ImageStabilization: 259

    Lens Info: 15.1, 60.4, 0, 0

    Lens Model: 15.1-60.4 mm