11 Replies Latest reply on Jul 13, 2012 7:33 AM by conroy

    Delete along a ND gradient?

    TLL... Level 3

      Hello all

       

      One of the characteristics of vertical aerial photography is a tendency for uneven exposure – even the latest million dollar + capture systems exhibit this problem. When you use 1000’s of these images to produce products you can end up with a striped appearance – not good. So along with other (IMO less successful) software tools we use Photoshop to try to address this issue. So far adding a neutral density gradient mask (layer) to the image helps a lot to even overall density. But when this initial unevenness also includes a loss of contrast on the light side you end up with an ‘even’ image that’s contrasty on one end and flat on the other.

       

      So without adding a bunch of screen shots (right now at least) tell me if this can be done:

       

      Image A is good contrast / brightness on left half, light and flat on right. Make image A copy layer. Adjust A copy so that right side ‘matches’ left side of A original. Create a new layer with a ND gradient that approximates what you want to keep/delete (doesn’t matter at this point) and use that as a ‘template’ (not sure if that’s the right word) to modify the image A copy. Like a layer mask?

       

      Oh, one more thing - this needs to 'batchable'

       

      Thanks!

        • 1. Re: Delete along a ND gradient?
          c.pfaffenbichler Level 9

          I would like to ask for those screenshots or lores images now, because I don’t quite follow, I’m afraid.

          • 2. Re: Delete along a ND gradient?
            conroy Level 5

            To modify the contrast, try an Adjustment Layer with a gradient in its mask. A Levels AL or Brightness/Contrast AL may do the trick.

            • 3. Re: Delete along a ND gradient?
              TLL... Level 3

              OK - here we go. First a series showing what I am doing, its OK but I wish to address the flatness of the image on the right side

               

              Current process.jpg

               

              Now a proposed solution to fixing the contrast. Keep in mind a couple things - the original images are huge (300+ mb), that's why using feathered selections won't work (250 px feather isn't enough) and whatever I do must be actionable - i.e. repeatable with variations for images across flight lines. Some adjustments differ more or less as the project dictates.

               

              Proposed process.jpg

              Hope this helps!

              • 4. Re: Delete along a ND gradient?
                TLL... Level 3

                "To modify the contrast, try an Adjustment Layer with a gradient in its mask."

                Thanks, please describe this step (I don't want to sound lame but what the heck )

                • 5. Re: Delete along a ND gradient?
                  TLL... Level 3

                  OK, I've tried using a gradient mask on a levels adjustment layer - works great! BUT, how do I save this adjustment layer/mask combo to apply to multiple images. I can save it as a .psd but not as a pattern to 'fill' with. So close here, any ideas?

                   

                  Masked_ADJ_layer.jpg

                  • 6. Re: Delete along a ND gradient?
                    conroy Level 5

                    how do I save this adjustment layer/mask combo to apply to multiple images.

                     

                    Instead of saving the masked AL, you can record an Action of making the AL and its mask, then run that Action as a batch process on a folder of image files. If the images are all the same size and require the same gradient mask and Levels parameter values then only one Action will be needed.

                     

                    Consider first saving a custom preset of the Levels values that you want. Then when you record the Action, just add the Levels AL and select the preset from the dropdown above the Levels controls then make the gradient in its mask and, finally, stop recording

                     

                    You run a batch process from File > Automate > Batch...

                    I think you can run it from Bridge, too, but I've not made much use of Bridge.

                    • 7. Re: Delete along a ND gradient?
                      TLL... Level 3

                      Hey thanks for helping me think this through. I use batches and scripting all the time. What is hanging me up is inserting the gradient mask at the adjustment level step - no matter what I use as a source, clipboard, fill from saved pattern or new layer - when I step through the record steps it works, but when I run the batch the level application using the applied mask either hangs or is not applied at all. I'll look into your suggestion in the morning. Please check back, maybe I'll post an .atn

                      • 8. Re: Delete along a ND gradient?
                        conroy Level 5

                        I used the Gradient Tool to make the gradient in the mask which was already targeted after creating the Adjustment Layer. The start and end locations of the gradient were included in the Action without enabling Allow Tool Recording. You might save a custom Gradient preset before recording the Action.

                         

                        Here's how the action looks in CS6 (I forgot to mention the Save As step earlier). It definitely works in batch mode in CS5.1 on OS X 10.6.8, too.

                         

                        Actions.png

                        • 9. Re: Delete along a ND gradient?
                          TLL... Level 3

                          Hello conroy, new day here and ready to attack this again. I forgot the specs - CS5 Ext, Win7 64 bit. I'm going to try to duplicate your action. Is it possible to post a link to your atn?

                           

                          Thanks!

                           

                          TLL

                          • 10. Re: Delete along a ND gradient?
                            TLL... Level 3

                            Update - SUCCESS! At least with recording the complete action and having it play back correctly. I don't know what I was doing wrong before but hey, who cares now, eh?

                             

                            As someone who has seen the overall quality of this forum decline dramatically over the years I just want to say THANKS for sticking around and helping me out. If there's anything I can do to help in the future I'll be lurking...

                             

                            TLL

                            • 11. Re: Delete along a ND gradient?
                              conroy Level 5

                              Great!

                               

                              I only discovered this forum a few weeks ago and it does seem incredibly quiet when you consider the millions of Ps users.