7 Replies Latest reply on Jan 12, 2010 8:01 AM by Panoholic

    Bug in Camera Raw's tone curve?

    01af Level 1

      Phil Harvey has released ExifTool 8.04 yesterday, and in the release notes he says, 'WARNING: Some Adobe utilities (Camera Raw 5.6, DNG Converter 5.6, Lightroom 2.6) have a bug which causes the tone curve to be incorrect for edited ARW images from some Sony cameras (A500, A550, A700, A850, A900, and maybe others)'.

       

      Can any Sony Alpha users confirm this? And will there be an intermediate bug fix, or will we have to wait for the next ACR version? Does anyone know when the bug was introduced, i. e. does it make sense to revert back to ACR 5.5?

       

      UPDATE: I have tried editing an A900 ARW raw file with ACR 5.6. I have changed the tone curve, saved the file, inspected the XMP file, loaded and edited the raw file again, saved it again, inspected the XMP file again. As far as I can tell, no problems with the tone curve. So I am wondering if Phil's allegation holds any water in the first place, and if so then under which circumstances the bug will emerge.

        • 1. Re: Bug in Camera Raw's tone curve?
          Ian Lyons MVP & Adobe Community Professional

          Ask him, he is usually happy enough to answer questions.

          • 2. Re: Bug in Camera Raw's tone curve?
            Graham in NC Level 1

            I used 5.6 in beta, and I've been using the release version with my a850 and a700 with good results. I have several custom tone curves loaded, but I normally use the Adobe standard curve.

             

            Regards,

            Graham

            • 3. Re: Bug in Camera Raw's tone curve?
              01af Level 1

              I think I got it ...

               

              When Phil says, "... incorrect for edited ARW images ...," then he means, edited in ExifTool. Editing a file possibly means changing its length. And the problem with Adobe tools obviously is, they have got the offsets to the various fields inside an ARW raw file hardcoded inside so they cannot properly handle edited (i. e. non-standard-length) ARW raw files.

               

              Okay, raw files usually are considered read-only. But it seems Adobe is able to handle edited copies of other kinds of raw files, so not being able to handle edited ARW files specifically seems to be a bug indeed.

              • 4. Re: Bug in Camera Raw's tone curve?
                Panoholic Level 2
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                01af wrote:


                the problem with Adobe tools obviously is, they have got the offsets to the various fields inside an ARW raw file hardcoded inside so they cannot properly handle edited (i. e. non-standard-length) ARW raw files.

                 

                 


                I don't have access to the source modules of Adobe tools, but I can assure you, that this is not the case. There is no "standard length", and there are no fixed offsets.

                 

                Gabor

                • 5. Re: Bug in Camera Raw's tone curve?
                  MadManChan2000 Adobe Employee

                  It is unclear to me from the description what the issue is. My questions would be:

                   

                  What in the ARW file, precisely, is being edited? The XMP in a sidecar? Other metadata in the ARW file itself? If so, which ones?

                   

                  When the description says, "the tone curve to be incorrect" -- which tone curve? The Camera Raw tone curve? If so, which one? The point curve? The parametric curve? Or are we talking about the in-camera Sony curve presets?

                   

                  Eric

                  • 6. Re: Bug in Camera Raw's tone curve?
                    ssprengel Adobe Community Professional & MVP

                    Eric,

                     

                    Phil said he submitted a bug report with Adobe which you may have seen, but we wouldn't have.  My interpretation of what he says is the white-balance is being interpreted wrong in files EXIFtool has monkeyed with, because EXIFtool may insert data into or remove data from the ARW header thus changing where the "tone curve" data starts, but Adobe's RAW engine is assuming a fixed offset for the "tone curve" data and is apparently getting junk which confuses what computes the WB.  As far as what "tone curve" means, please discuss with Phil if this is really a mystery.

                     

                    See the following somewhat cryptic mention of the problem on his forum:

                    http://cpanforum.com/threads/8995#12078

                     

                    "Edited images from the A700, A850 and A900 are not read properly by Adobe Photoshop CS4 Camera Raw 5.6, DNG Converter 5.6, or LightRoom 2.6 (the white balance is wrong). I have tracked down the problem and determined that the Adobe utilities are assuming a fixed offset for some data in the ARW image (bad Adobe!). Neither the Apple OS X 10.5.8 utilities, dcraw 8.99 nor Capture One 5.0.1 have any problems with these edited images."

                    • 7. Re: Bug in Camera Raw's tone curve?
                      Panoholic Level 2

                      This means, that offsets within a tag are wrongly assumed to be fixed; my comment above related to the offsets to the tags themselves.

                       

                      Sorry for the confusion.

                       

                      Gabor