13 Replies Latest reply on Jan 26, 2011 9:20 AM by teedubb9

    Non destructive editing in ACR.

    design_def

      Many of the promo videos describe ACR editing as being 'non-destructive', is this meant in the way of not destroying the original file in any way, i.e. leaving in in tact, or that the changes made in ACR are not degrading the newly created image as opposed to editing in Photoshop? Is there any way / any Adobe plans to indicate which edits in Photoshop actually degrade the image, however slightly? Maybe for future Photoshop updates there could be an indicator of which edits would have been better to have been done previously in ACR?

        • 1. Re: Non destructive editing in ACR.
          rasworth Level 1

          ANY image edit/adjustment in Photoshop that is not a separate layer modifies the image data.  Of course, the edit is not "consumated" until the image is saved to the original file name.

           

          Richard Southworth

          • 2. Re: Non destructive editing in ACR.
            MadManChan2000 Adobe Employee

            In a nutshell, when you open Camera Raw to edit an image, Camera Raw does

            not modify the pixel data in that image.

             

             

            Many of the promo videos describe ACR editing as being 'non-destructive', is

            this meant in the way of not destroying the original file in any way, i.e.

            leaving in in tact, or that the changes made in ACR are not degrading the

            newly created image

             

            • 3. Re: Non destructive editing in ACR.
              JimHess-5IFZWq Level 3

              rasworth wrote:

               

              ANY image edit/adjustment in Photoshop that is not a separate layer modifies the image data.  Of course, the edit is not "consumated" until the image is saved to the original file name.

               

              Richard Southworth

              In Photoshop that is true.  However, editing in Camera Raw is different.  Editing with ACR does not modify the pixel data in any way.  All modifications are stored as metadata either in a sidecar file or in the header section of the image file.  And that metadata can always be cleared so that the original image can be displayed again.

              • 4. Re: Non destructive editing in ACR.
                rasworth Level 1

                Jim,

                 

                Yes, I understand the difference between editing in ACR and in Photoshop.  The op's question was which edits in Photoshop were non-destructive, I believe I answered correctly.

                 

                Richard Southworth

                • 5. Re: Non destructive editing in ACR.
                  JimHess-5IFZWq Level 3

                  rasworth wrote:

                   

                  Jim,

                   

                  Yes, I understand the difference between editing in ACR and in Photoshop.  The op's question was which edits in Photoshop were non-destructive, I believe I answered correctly.

                   

                  Richard Southworth

                  Well, I guess you and I are reading the original question differently.  He was talking about nondestructive editing in ACR, and you are talking about editing in Photoshop.  I thought your answer needed a bit of clarification.  Sorry if I offended you.  I will make it a point not to involve myself in any of your discussions in the future.

                  • 6. Re: Non destructive editing in ACR.
                    design_def Level 1

                    Thank you all for the comments so far. I thought it would be interesting to discuss exactly what Adobe mean by 'non-destructive' editing, as a Photoshop user from the early days, we were taught that all editing in Ps. degraded the file to some extent, so ACR is a real development, maybe? I'm trying to work out if the 'non-destructive' claims are saying that the original file is still in tact, but if you adjust the exposure slider in ACR for instance would this be just as degrading to the ( new ) image as adjusting the levels in Ps. ?

                    • 7. Re: Non destructive editing in ACR.
                      xbytor2 Level 4
                      but if you adjust the exposure slider in ACR for instance would this be just as degrading to the ( new ) image as adjusting the levels in Ps. ?

                       

                      Adjusting the exposure slider in ACR does not modify the image bits. You can save the file, come back later, and reset the slider to 0 and all the bits are still there.

                       

                      In PS, you can modify the exposure destructively or non-destructively. If you want to keep your bits in tact, use an Exposure Adjustment Layer. If you want your bits modified, use Image->Adjustments->Exposure and your bits are forever changed when you save the file.

                      • 8. Re: Non destructive editing in ACR.
                        JimHess-5IFZWq Level 3

                        Even if you use adjustment layers in Photoshop the situation is different.  In most instances the final image will be flattened, and all adjustment layers are eliminated.  After that happens there is no way that you can restore that particular image to its original state.  This is where ACR is different.  Camera Raw never makes changes to the image data.  The changes are either stored in the XMP sidecar file (as is the case with native raw images) or in the file itself (as in DNG, JPEG or TIFF).  In the case of the latter the metadata changes are stored within the header section of the image.  But again, the image data i.e. the actual pixels are never altered by Camera Raw.  The changes made in Photoshop will eventually become destructive to a certain degree because Photoshop ultimately will alter the image data.  In most cases, however, it would take quite a number of incremental saves of the file before that damage will be visible.

                        • 9. Re: Non destructive editing in ACR.
                          Jeff Schewe Level 5

                          design_def wrote:

                           

                          I'm trying to work out if the 'non-destructive' claims are saying that the original file is still in tact, but if you adjust the exposure slider in ACR for instance would this be just as degrading to the ( new ) image as adjusting the levels in Ps. ?

                           

                          "Non-destructive" is a marketing term meaning parametric editing of metadata rather than actual pixel level edits. Photoshop can edit parametrically when using adjustment layers. This is considered non-destructive as well. But the advantage of Camera Raw's parametric editing is that all post processing is done in an optimized processing pipeline in an optimal order for optimal results...in the case of Photoshop, when processing the flattening of adjustment layers, Photoshop has no alternative but to process them in the order in which the user stacked them-rarely an optimal order (IMHO).

                           

                          You are getting far too wrapped up in definitions instead of trying to understand the principles. Photoshop at it's roots is a pixel level editing tool. It can apply parametric edits (deferred edits via adjustment layers) but when you touch the image with other tools, you have to actually run the algorithms on the pixels which changes them...

                           

                          With Camera Raw, every edit is a parametric edit that will not be applied until the final processing into an RGB (or grayscale) file. The order is fixed and the processing is optimized. The original file is not altered by processing out to a new file. You can clear the settings of a raw file to get back to "default". Camera Raw (and Lightroom) treat the raw file as a "Read-Only" file (with the exception of date/time fixes in Lightroom).

                          • 10. Re: Non destructive editing in ACR.
                            teedubb9

                            This was a bit of a shocker to me: From Scott Kelby's book "The Adobe Photoshop CS5 Book for Digital Photographers" under the heading "Editing JPEG & TIFF images in Camera Raw:"

                             

                            "But there is a big distinction between editing JPEG or TIFF images and editing a RAW image. If you click the Done button, you're actually affecting the real pixels of the original JPEG or TIFF, whereas, if this were a RAW image, you wouldn't be."

                             

                            Here I thought the edits to JPEGS in Camera Raw were non-destructive. It doesn't sound like that is the case (according to Kelby).

                            • 11. Re: Non destructive editing in ACR.
                              Noel Carboni Level 7

                              Destructive is the wrong word.  It gives negative connotations in cases where what is really happening is pixel values are being changed.  This is not always a bad thing!

                               

                              If you paint your house, do you consider that destructive?  Sure, you may be destroying its old look, but isn't that the point?

                               

                              However, the word seems to have stuck, and I guess we have to use it.  Sigh.

                               

                              Always keep this in mind:

                               

                              Nothing is EVER truly destructive unless you save over your original file.

                               

                              With some kinds of files, e.g., camera raw .CR2, .NEF, etc., you simply CAN'T save over the original file.  With others, TIFF, JPEG, etc. you can - but no one says you have to!

                               

                              Make a habit NEVER to save over your original file, and you will never destroy your ability to start over again.

                               

                              -Noel

                              • 12. Re: Non destructive editing in ACR.
                                Jeff Schewe Level 5

                                teedubb9 wrote:

                                 

                                "But there is a big distinction between editing JPEG or TIFF images and editing a RAW image. If you click the Done button, you're actually affecting the real pixels of the original JPEG or TIFF, whereas, if this were a RAW image, you wouldn't be."

                                 

                                 

                                Functionally incorrect...when you click Done in Camera Raw, Camera Raw will save the settings inside the JPEG or TIFF file in the XMP metadata. The pixels are not actually processed at this time, only the metadata is being changed. Adobe products like Bridge or Lightroom can read the metadata and show a preview of the changed metadata but the original pixels are not actually being changed until you process the JPEG or TIFF into Photoshop and save the image.

                                • 13. Re: Non destructive editing in ACR.
                                  teedubb9 Level 1

                                  Thank you Noel & Jeff, You've been very helpful. I went over to Kelby's blog to let him know of the inaccuracy written in his book. Thanks again.