13 Replies Latest reply on Apr 12, 2014 10:14 PM by areohbee

    Precedence Order

    Petrula Level 1

      What is the precedence order in Adobe Camera Raw CC?

       

      For example, what is the precedence order of applying White Balance, Basics, Tone Curve, Split Toning, Camera Calibration, etc.?

       

      For Tone Curve, one usually only applies Parametric or Point - not both.

      However, what is the precedence order of Parametric and Point if you apply both?

       

      Thanks in advance.

        • 1. Re: Precedence Order
          Jeff Schewe Level 5

          Are you asking what order the user should use the controls or what order the processing pipeline applies the adjustments? In the case of user order, it doesn't matter other than for the fact that white balance should prolly be done first because you need a resonable white balance to be in place before deciding on the tone adjustments.

           

          Generally you'll want to adjust Exposure before Highlights/Shadows and White & Black points to finesse the end points of the tone curve. But to ACR, it doesn't matter what order you apply things because the pripeline will process things in it's own order.

           

          If you are wanting to know the order of the processing pipeline, sorry, that's pretty much proprietary information. Some info can be gleened by reading the DNG Specification, but the exact order is really only know by the ACR engineers.

          • 2. Re: Precedence Order
            areohbee Level 6

            Petrula wrote:

             

            what is the precedence order of Parametric and Point if you apply both?

            My guess: curve is curve - no precedence order. In other words, parameters & points are combined before application.

             

            Note: the parametric view shows the combined curve.

             

            FWIW (probably not much), although I agree with you, that "usually" (meaning >50% of the time), people adjust one or the other, I don't think it's particularly uncommon for both to be adjusted (I do it quite often) - could be wrong..

             

            Also, it's been the consensus on this forum for a long time, that curve follows basics in the processing pipeline, thus the reason setting white/black points via curve prior to adjusting basics is discouraged (i.e. reason: you are constraining output of basics, rather than input - and basics are tuned for the full raw tone set, thus it can lead to non-optimal toning if you do tone curve first). For example: exposure rolloff  and special whites slider behavior occur near the right end of the raw data, not the right end of the data as clamped by the tone curve.

             

            PS - Since I'm just guessing, I'm not violating any NDA, but I'm about 9X% sure what I've said here is 9X% correct.

             

            R

            • 3. Re: Precedence Order
              Petrula Level 1

              I am concerned about the processing pipeline order.

               

              Thanks

              • 4. Re: Precedence Order
                Jeff Schewe Level 5

                Petrula wrote:

                 

                I am concerned about the processing pipeline order.

                 

                Thanks

                 

                 

                Well, then you'll need to wait till an ACR engineer answers (but don't expect too much detail because the info is proprietary) or download the DNG SDK (if you understand how to read the SDK). Rob's "guesses" not withstanding, the end users doesn't really need to know because, well, there's nothing the end user can do to alter the processing pipeline...

                • 5. Re: Precedence Order
                  areohbee Level 6

                  Petrula wrote:

                   

                  I am concerned about the processing pipeline order.

                  I think it would help us give you a better answer if you elaborate your concerns.

                   

                  As Jeff said, for the most part it makes no difference (to end user) and therefore shouldn't concern you (it may even vary from version to version in the interest of optimizing performance..).

                   

                  But as you may have noticed, occassionally it does impact end result (don't interpret wrong: same settings produce same results regardless of sequence of adjustment), in subtle but signficant ways, and can affect optimal settings.

                   

                  In case it helps:

                  * I think camera calibration can be thought of as preceding HSL & Split-toning.

                  * Once upon a time, somewhat counter-intuitively, locals, at least to some extent, were discovered to precede globals, which means if you apply +exposure locally, blown out regions may not be recoverable via global -highlights (this may be a good thing or may be a bad thing depending on what you are trying to accomplish, but in some rare cases it helps to know about it)... - again: this may no longer be true - dunno..

                  * crud: I was gonna make another point here but forgot what it was.

                   

                  Rob

                  • 6. Re: Precedence Order
                    Andrew_Hart Level 2

                    I think that it's just too silly that we can't be told what order edits are made in.

                     

                    As if knowledge about that could somehow enable any competitor to reverse engineer any aspect of ACR/LR or get some advantage over Adobe. Such a notion seems ridiculous.

                     

                    And in at least one area it is very important to know the precedence, namely noise reduction.

                     

                    It is well established, and confirmed by Eric Chan himself in a thread I participated in some years ago, that any edit which increases contrast will enhance luminance noise.

                     

                    There was some other edit which had the same effect but I can't now recollect it.

                     

                    So, should we deal with noise first, alone, on its own, and finish editing (the "Done" button) and then resume editing for everything else?

                     

                    Or does ACR/LR do noise before anything else, meaning we don't have to bother with a double edit exercise?

                     

                    Come on, Adobe, how about just a little help here please.

                    • 7. Re: Precedence Order
                      Andrew_Hart Level 2

                      Got it.

                       

                      Here's the thread I was talking about in post #6 above.

                       

                      http://forums.adobe.com/message/3219496#3219496

                       

                      See Eric Chan's post #27.

                      • 8. Re: Precedence Order
                        Andrew_Hart Level 2

                        In post #6 I said:

                         

                        "So, should we deal with noise first, alone, on its own, and finish editing (the "Done" button) and then resume editing for everything else?

                         

                        That was probably stupid of me. As I recollect, the question of numerous consecutive but separate in time editing sessions was considered by Lawrence (Hudechrome) in the thread I referenced in post #7 above.

                         

                        I think he concluded, without correction from others, that when you press the Done button after the last edit in the last editing session, ACR (and presumably, LR) processes all the combined edits from all editing sessions, in the predetermined order of the processing pipeline.

                         

                        But regarding noise reduction, we may possibly have some insight regarding precedence. In Eric Chan's post I referenced in post #7 above, he said:

                         

                        "Yes, if you increase contrast & saturation, you will boost noise. This can happen to any image, regardless of the source. It just means you'll need to apply more noise reduction, or apply weaker tonal changes (i.e., balance the increase in noise with the increase in contrast/saturation)."

                         

                        Having reconsidered his choice of words carefully, and in the context of that thread, I think it is eminently reasonable to infer that he was saying that, in the predetermined pipeline, noise reduction is NOT performed before any edit to the contrast or saturation sliders themselves or, perhaps, more broadly and more likely, any other edit which affects contrast or saturation.

                         

                        What a pity, if that is the true position. Having to add excessive noise reduction to cope with a noisy image in which the noise has been exacerbated by ARC's processing pipeline itself just increases the prospect of significant loss of detail.

                        • 9. Re: Precedence Order
                          Jeff Schewe Level 5

                          Andrew_Hart wrote:

                           

                          Having reconsidered his choice of words carefully, and in the context of that thread, I think it is eminently reasonable to infer that he was saying that, in the predetermined pipeline, noise reduction is NOT performed before any edit to the contrast or saturation sliders themselves or, perhaps, more broadly and more likely, any other edit which affects contrast or saturation.

                           

                          No, what he said is when you increase contrast, noise becomes more visible requiring additional noise reduction. You are reading too much into this. Sorry if you aren't happy that the processing pipeline is mysterious, but since you as the user can't change it, it really doesn't matter. Eric can answer those types of questions but in general, the ACR processing pipeline engine is considered proprietary.

                          • 10. Re: Precedence Order
                            areohbee Level 6

                            Andrew, I think you need to try stuff, and report if you have problems, or note processing-dependency-related behaviors.

                             

                            Trying to pre-determine what to do based on pre-knowledge of processing order is a recipe for frustration and exasperation, and is like the exact opposite of how ACR was designed to be used (plus Adobe simply does not provide the information..).

                             

                            Adobe tried to make it so that you could (for the most part) adjust whatever whenever and not worry too much about precedence order. If they failed, then do tell (via real example).

                             

                            But one thing I agree with you about: just because you can't change it, does not mean it doesn't matter.

                             

                            Here is a starter list of "order related" issues that I feel are (or may be) important:

                            * Tone curve follows basics (so don't use white point on curve as a substitute for +exposure..).

                            * Camera calibration precedes HSL & Split-toning.. (so choose camera calibration profile before adjusting colors..).

                            * Tonal range of shadows slider is tied to exposure adjustment, so adjust exposure before shadows (ditto for highlights..).

                            * Locals precede globals, which rarely but sometimes matters..

                            * Spot adjustment may be slower if lens corrections are applied, so if you have problems with spot performance, consider disabling lens corrections until you're done with spots.

                             

                            Feel free to add to it..

                             

                            Note: with few exceptions, things are arranged in "recommended order for adjustment" from top to bottom, so many people just edit in the recommended order thus dependency issues never arise. Personally, I like to have baseline detail settings (including luminance noise reduction) done first (upon import actually, based on ISO), then adjust camera calibration, then procede in recommended top-down order (more or less), with the most notable exception that blacks slider must be attended to before trying to do too much with the basic sliders above it.

                             

                            PS - regarding noise reduction: I think you can adjust it whenever you feel like it, with the understanding that if you increase exposure or contrast afterward, you may need to bump NR. (there are some performance reasons why some people will disable NR until after some stuff, but I don't remember details). In other words, trying to double-process, first with NR, then export, then adjust contrast (to try and get around what you think may be non-optimal precedence order), is not necessary, and would probably create more problems than it solves, if it solves any..

                             

                            Rob

                            • 11. Re: Precedence Order
                              Andrew_Hart Level 2

                              Thanks for the feedback, Rob. Some very useful tips in there.

                               

                              There's something wrong with the engineering behind this forum.

                               

                              I've received two email responses from you which simply have not appeared as posts in the forum itself.

                               

                              A couple of days ago I tried to, but could not, login and was informed that they were doing major upgrades and was told to try again later.

                               

                              Since then, when posting in this thread I've experienced difficulties. Twice my proposed posts have been unsuccessful, receiving a message that there was an error in processing the post and to try submitting it again. Repeated attempts over several minutes between each ended in failure.

                               

                              On one occasion, the cursor in the Message field just disappeared and I was unable to continue adding to or editing my proposed post.

                               

                              You now can't copy and paste from within your own proposed post, which I seem to remember was possible in the past.

                               

                              Anyone else experiencing any of these, or other, problems?

                              • 12. Re: Precedence Order
                                MikeKPhoto Level 2

                                While agree somewhat there is no particular order to apply adjustments I find, for my workflow and images, better to apply lens correction, then go to exposure and the other controls. Some lenses have worse vignetting than others and when applied after say exposure and highlights, you have to go back and readjust.

                                 

                                The order of the other controls do not seem to matter

                                 

                                MK

                                • 13. Re: Precedence Order
                                  areohbee Level 6

                                  Andrew_Hart wrote:

                                   

                                  Thanks for the feedback, Rob. Some very useful tips in there.

                                  You're welcome.

                                   

                                  Andrew_Hart wrote:

                                   

                                  There's something wrong with the engineering behind this forum.

                                   

                                  I've received two email responses from you which simply have not appeared as posts in the forum itself.

                                  Sorry - I deleted them - after posting, I changed my mind..

                                   

                                  Andrew_Hart wrote:

                                   

                                  A couple of days ago I tried to, but could not, login and was informed that they were doing major upgrades and was told to try again later.

                                  Yes, forums were down for maintenance.

                                   

                                  Andrew_Hart wrote:

                                   

                                  Since then, when posting in this thread I've experienced difficulties....

                                  I sometimes have problems too (but even before then) - which is why I periodically copy my posts to the clipboard, in case I have to reload the page or something.. firefox

                                   

                                  Cheers,

                                  Rob