14 Replies Latest reply on May 28, 2009 8:13 AM by Bill_Janes

    Why no lens correction for the rest of us?

    dorin_nicolaescu Level 5

      Since ACR 5.3/LR 2.3, I think, there is built-in on-the-fly lens correction for at least some Panasonic cameras. We know it's there - there's no question, though it was never mention in official Adobe info.

       

      If the lens correction is there and it works great (I tried some LX3 files - both quality and performance is great), why not make it available for other cameras/lenses?

       

      Even if is not fully automatic, but involves some slider adjustment, that would be a great relief for those who use third-party plugins like PTLens.

        • 1. Re: Why no lens correction for the rest of us?
          Jeff Schewe Level 5

          dorin_nicolaescu wrote:

           

          why not make it available for other cameras/lenses?

           

          Because it's one thing to quietly include it for that single camera as a method of developing a better relationship with Panasonic (and fixing some SERIOUS lens performance issues) and it's an entirely different thing to include it for the nearly 200 cameras Camera Raw supports and the potentially hundreds of lenses to go on those cameras? DOH!!!!

           

          Just a guess here, but I suspect auto corrections of all sorts may end up in future versions of ACR...but all this stuff takes time, ya know? And Adobe can't add new features and functionality in dot releases (due to accounting rules).

          • 2. Re: Why no lens correction for the rest of us?
            dorin_nicolaescu Level 5

            Understood (about hundreds of lenses).

             

            But does it necessary have to be automatic? Meanwhile, I'd be more than happy to have to drag two sliders to get these corrections done. Heck, I could even make some presets if I'm lazy to drag sliders.

            • 3. Re: Why no lens correction for the rest of us?
              Jeff Schewe Level 5

              dorin_nicolaescu wrote:

               

              ...I'd be more than happy to have to drag two sliders to get these corrections done.

               

              What part of no new features didn't you get? Adding sliders would be a fundamental change in the UI and would add features which due to accounting rules, Photoshop (and by extension Camera Raw) can't change it's feature set between versions. The only exception is when an update is made in the same fiscal quarter as the main release of the Ps update....then features can be added such as the change from ACR 5.0 to 5.2 because 5.2 shipped before the end of Adobe's quarter.

              • 4. Re: Why no lens correction for the rest of us?
                Bill_Janes Level 2

                dorin_nicolaescu wrote:

                 

                Since ACR 5.3/LR 2.3, I think, there is built-in on-the-fly lens correction for at least some Panasonic cameras. We know it's there - there's no question, though it was never mention in official Adobe info.

                 

                If the lens correction is there and it works great (I tried some LX3 files - both quality and performance is great), why not make it available for other cameras/lenses?

                 

                Even if is not fully automatic, but involves some slider adjustment, that would be a great relief for those who use third-party plugins like PTLens.

                 

                What aberrations are corrected in these Panasonic cameras and what features would you like to have added to Camera Raw and which of these are reasonably likely to be implemented in ACR? The major lens aberrations are summarized in this diagram on the hyperphysics site:

                 

                http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/aberrcon.html

                 

                ACR already has a facility to correct lateral chromatic aberration. While vignetting is not an lens aberration, but rather is imposed by mechanical limitations of the lens, it can also be removed by ACR. Distortion is the other aberration than can be readily removed by software. Distortion correction is an often requested feature addition for ACR. While such correction is not currently available in ACR, Martin Evening explains how one can achieve these corrections in ACR through the use of smart objects in Photoshop. The movie addresses correction of keystoning (which again is not a lens aberration), but the same method can be used for correction of barrel and pincushion distortion.

                 

                http://photoshopnews.com/wp-content/uploads/2009/05/psn-perspectiveacr-low.mov

                 

                As far as I know, the other aberrations are much more difficult to correct in software. Spherical aberration can be reduced by deconvolution techniques as shown by NASA's experience with the Hubble space telescope. Currently, DXO is the premiere software for removing lens aberrations, and from reading their web site, it appears that their approach is to mask the effects of these aberrations through the use of sharpening techniques rather than eliminating them.

                 

                 

                 

                 

                 

                 

                 

                 

                 

                 

                 

                 

                 

                 

                 

                lens pincushion/barrel distortion, vignetting,   chromatic aberration, and perspective

                • 5. Re: Why no lens correction for the rest of us?
                  dorin_nicolaescu Level 5
                  Distortion is the other aberration than can be readily removed by software.

                  Yes, by what software? We're talking ACR here and it's not available in ACR. (Well, actually I use Lightroom, but prefer to post develop-specific questions here, since they go hand in hand anyway, but the ACR forum is more focused on image-processing. And Photoshop is not a part of Lightroom.)

                   

                  My question was why distortion is not available if it's already implemented and works for Panasonic cameras. You see, it works. The code is there... but I can't use it for my Nikon. The key i my question was "for the rest of us"...

                  • 6. Re: Why no lens correction for the rest of us?
                    JimHess-8IPblY Level 3

                    I don't follow the Panasonic line very closely.  But I seem to recall that certain types of distortion were well documented, and Panasonic did something to correct it, and Adobe did the same.  If there is a specific type of distortion you need to have corrected, submit a feature request.

                     

                    Just one other thought.  With the Panasonic there is only one lens to worry about.  Can you imagine the monumental task of trying to provide lens correction for every lens available for a digital SLR?  I don't think it's a very realistic idea.

                    • 7. Re: Why no lens correction for the rest of us?
                      Bill_Janes Level 2

                      dorin_nicolaescu wrote:

                       

                      Distortion is the other aberration than can be readily removed by software.

                      Yes, by what software? We're talking ACR here and it's not available in ACR. (Well, actually I use Lightroom, but prefer to post develop-specific questions here, since they go hand in hand anyway, but the ACR forum is more focused on image-processing. And Photoshop is not a part of Lightroom.)

                       

                      My question was why distortion is not available if it's already implemented and works for Panasonic cameras. You see, it works. The code is there... but I can't use it for my Nikon. The key i my question was "for the rest of us"...

                       

                       

                      You have partially answered my question about what corrections are currently implemented in ACR for your Panasonic camera. Distortion, but what kind of distortion? Pincushion, Barrel, Volume Anamorphosis, Keystoning (or other persepctive problems)? The first two are lens aberrations but the latter two are not, and are present in all lenses. (Volume anamorphosis is seen with wide angle lenses where  three-dimensional objects that are not on the optical axis of the camera can appear stretched out, i.e. people at the edge of the field appear fat). Jeff Schewe intimated that the corrections were instituted for the Panasonic because of "some SERIOUS lens performance issues" with that camera. Perhaps, such corrections are less needed for Nikon cameras which may have better lenses. Since perspective distortion can be seen with all lenses, correction in ACR would be a valuable asset.

                       

                      Incorporation of Photoshop's Lens Correction filter into ACR would address most of your concerns and hopefully will be included in a future version of ACR, but in the meantime you could use Martin Evening's approach with smart objects in Photoshop. I don't know if smart objects are in Lightroom, since I don't use it.

                      • 8. Re: Why no lens correction for the rest of us?
                        rasworth Level 1

                        For a nominal contribution to Tom Niemann, one can procure my favroite Photoshop plug-in, PTLens.  It does strive to maintain a database of all digital camera/lens combinations, and in my experience has done well is this regard.  It corrects geometric lens distortion, as well as perspective, vignetting, and chromatic aberration.  The geometric correction is automatic, the other corrections are manual.

                         

                        It can be used in CS4 with ACR smart objects, appearing as a smart filter complete with mask.  So one can retain all of the adjustment capability from ACR along with the lens correction.

                         

                        Richard Southworth

                        • 9. Re: Why no lens correction for the rest of us?
                          Singh, Shangara Level 1
                          Incorporation of Photoshop's Lens Correction filter into ACR would address most of your concerns and hopefully will be included in a future version of ACR, but in the meantime you could use Martin Evening's approach with smart objects in Photoshop.

                          The SO approach will only work if you are doing multiple corrections. For one-off corrections, such as perspective correction, using a SO doesn't make a difference.

                           

                          • Import raw as a SO.
                          • Use Lens Correction to correct vertical perspective and scale (make a note of settings).
                          • Flatten.
                          • Import raw as normal image.
                          • Apply same Lens Correction settings.
                          • Flatten.
                          • Compare two using Differnce blend mode.
                          • Result: black.
                          • 10. Re: Why no lens correction for the rest of us?
                            Bill_Janes Level 2

                            Jumping Walrus wrote:

                             

                            The SO approach will only work if you are doing multiple corrections. For one-off corrections, such as perspective correction, using a SO doesn't make a difference.

                             

                             

                            I don't get your point. In Martin Evening's example, he used the method for perspective correction only, and it worked just fine. At the same time, one could also do correction of pincushion or barrel distortion. Did you watch the movie?

                            • 11. Re: Why no lens correction for the rest of us?
                              dorin_nicolaescu Level 5

                              Thanks everyone for your posts.

                               

                              First, I should have been more specific about what kind of correction I am talking about — that's lens distortion: barrel or pincushion. ACR/Lightroom automatically correct the Pana lens for lens distortion and chromatic aberrations (i.e. I am not asking for Volume Anamorphosis, spherical abberatrions etc.).

                               

                              Second, sorry, but I feel like we're speaking different languages (that's right, English is not my native language). Yes, I am aware I could use PTLens, the Lens Correction plugin etc., But the point of my OP was "why lens correction is not available in ACR for all cameras, if it's already implemented for some". After all, the math behind distortion corection of a Pana lens, is the same for any other lens in the world!

                               

                              Third, yes, it's true that in the case of Panasonic LX3, you have to deal with one lens, and in case of DSLRs you have to take care of many hundreds. The thing is, to have fully automatic correction, like in LX3 case, one has to have a set of predifined parameters for each focal length. If you don't have a lens database, definning the input parameter can be left to the user, which in terms of UI means adding 2-3 more sliders.

                               

                               

                              Well, from Jeff's response I understood, that while the core routines for correcting distortion is already there in ACR/Lightroom, the whole thing is just not ready yet to be exposed to the end-user in a way Adobe thinks it should be. Probably, Adobe wants it to be fully automatic, and that involves building a lens database. What's left to us, is wait and see and hope the next major release will have distortion correction for everyone.

                              • 12. Re: Why no lens correction for the rest of us?
                                Bill_Janes Level 2

                                dorin_nicolaescu wrote:

                                 

                                 

                                 

                                First, I should have been more specific about what kind of correction I am talking about — that's lens distortion: barrel or pincushion. ACR/Lightroom automatically correct the Pana lens for lens distortion and chromatic aberrations (i.e. I am not asking for Volume Anamorphosis, spherical abberatrions etc.).

                                 

                                Second, sorry, but I feel like we're speaking different languages (that's right, English is not my native language). Yes, I am aware I could use PTLens, the Lens Correction plugin etc., But the point of my OP was "why lens correction is not available in ACR for all cameras, if it's already implemented for some". After all, the math behind distortion corection of a Pana lens, is the same for any other lens in the world!

                                 


                                 

                                There is no reason to be sorry about your English, since you are communicating quite effectively. The review of the LX3 by the Imaging-resource is quite interesting. The Leica lens on this camera has high distortion, but this is corrected for JPEGs by the camera firmware and in raw by SILKYPIX, the raw converter that ships with the camera. Perhaps Adobe felt compelled to offer such correction for this camera in order to remain competitive with SILKYPIX. It would be embarrassing for them to be outdone by this lowly raw converter. Hopefully, such correction will be extended to other cameras and lenses.

                                 

                                http://www.imaging-resource.com/PRODS/LX3/LX3A4.HTM

                                 

                                Third, yes, it's true that in the case of Panasonic LX3, you have to deal with one lens, and in case of DSLRs you have to take care of many hundreds. The thing is, to have fully automatic correction, like in LX3 case, one has to have a set of predifined parameters for each focal length. If you don't have a lens database, definning the input parameter can be left to the user, which in terms of UI means adding 2-3 more sliders.

                                 

                                 

                                Well, from Jeff's response I understood, that while the core routines for correcting distortion is already there in ACR/Lightroom, the whole thing is just not ready yet to be exposed to the end-user in a way Adobe thinks it should be. Probably, Adobe wants it to be fully automatic, and that involves building a lens database. What's left to us, is wait and see and hope the next major release will have distortion correction for everyone.

                                 

                                Yes, automatic correction would be desirable, but several sliders (such as already present in the Photoshop lens correction filter) would be better than nothing. As you say, the core routines are already in ACR and also in the Photoshop Lens Correction filter.

                                • 13. Re: Why no lens correction for the rest of us?
                                  rasworth Level 1

                                  Dorin,

                                   

                                  Yes, the math may be the same for correction on all lenses (although I'm not completely sure this is true, since some lenses have more complicated distortion than others), but the parameters vary from lens to lens and even for focus distance.  I've contributed images to PTLens for new lenses, and have an appreciation for how much effort Niemann expends keeping the database up to date.  So I believe it would be a major effort on Adobe's part to incorporate correction - they might be better off to license the PTLens database and avoid having to collect/generate the data.  In any event I don't find it much of a handicap to do it within Photoshop for those images that are other than snapshot category; for the latter I save directly out of ACR and am not overly worried about some slight distortion..

                                   

                                  Richard Southworth

                                  • 14. Re: Why no lens correction for the rest of us?
                                    Bill_Janes Level 2

                                    rasworth wrote:

                                     

                                    Yes, the math may be the same for correction on all lenses (although I'm not completely sure this is true, since some lenses have more complicated distortion than others), but the parameters vary from lens to lens and even for focus distance.

                                     

                                    Yes, some lenses have higher order distortion that varies from barrel to pincushion across the field, as explained in this link to the DXO web site.

                                     

                                    http://www.dxo.com/us/photo/dxo_optics_pro/optics_geometry_corrections/distortion

                                     

                                    So I believe it would be a major effort on Adobe's part to incorporate correction - they might be better off to license the PTLens database and avoid having to collect/generate the data.  In any event I don't find it much of a handicap to do it within Photoshop for those images that are other than snapshot category; for the latter I save directly out of ACR and am not overly worried about some slight distortion.

                                     

                                    It would indeed be a Herculean effort for Adobe to accumulate a database for the 200 cameras (and many hundreds of lenses) that ACR supports. Even DXO which charges US $240 for their Optics Pro Elite supports a limited number of lenses for professional cameras. For example, for the Nikon D3x, they only support 16 Nikkor lenses and 3 Sigma lenses. I do not think that automatic distortion correction with ACR is likely for many cameras and lenses in the near future.

                                     

                                    Nonetheless, the features in the Photoshop Lens Correction Filter could be implemented with relative ease. Chromatic aberration can be corrected without a database. The Nikon D3 and other newer Nikon cameras automatically correct chromatic aberration with Nikkor and 3rd party lenses with JPEGs and encode correction metadata in the raw file for use with their own raw converter.