10 Replies Latest reply on Aug 17, 2015 4:46 PM by 3perf

    HDR Merge: Deghosting doesn't seen to work on Canon RAW images?

    3perf Level 1

      Hi,

      attempting to HDR Merge some raw images from Canon EOS cameras, Lightroom appears to apply zero deghosting, irrespective of which level I tell it to use. I've tried series of three images, 3 stops apart, from both an EOS 350D and a 7D. Since nobody else seems to have reported this, I'm wondering if this is a problem specific to my machine? Running Lightroom CC 2015 [1014445] on Mac OSX 10.9.2.

       

      3p.

        • 1. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
          trshaner Adobe Community Professional & MVP

          It would help if you can post screenshots of the three files and tell us what in the picture needs deghosting. It works for me, but can have issues with stitching on certain image types (sky, water). Stitching errors may be the cause of the deghosting problem.

          • 2. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
            3perf Level 1

            Here are zoomed-in screenshots of the original files:

             

            LR6 deghost fail EV-3.png

            LR6 deghost fail EV0.png

            LR6 deghost fail EV+3.png

             

            And here is the final result. This one was with maximum deghosting, however it's 100% identical to a non-deghosted version.

            The larger defocused leaves in the foreground are the part that would require deghosting to work.

            LR6 deghost fail merged, align off, tone on, deghost high.png

             

            What do you mean by "stitching errors"? This isn't a stitched panorama. I'm only trying to bring together different exposures that are a few EVs apart.

            • 3. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
              trshaner Adobe Community Professional & MVP

              3perf wrote:

              I've tried series of three images, 3 stops apart, from both an EOS 350D and a 7D.

              Three stops (3 EV) bracketing is too large for good results. Also don't use the lens aperture setting for bracketing, which will cause the images to have different depth of field. Only use the shutter speed for bracketing. A bracket of one EV up to no more than two EV will provide better tonal results and may improve the deghosting.

               

              "What do you mean by "stitching errors"? This isn't a stitched panorama."

               

              The bracketed images are stacked as layers and then areas that are over or under exposed are masked out. The masked layers are then "merged" such that they are seamlessly combined (stitched) into one image. The deghosting process also masks out objects from one or more image layers. LR Photo Merge to HDR doesn't appear to work well deghosting objects that only move slightly from one bracketed image to the next. Here's an example:

               

              HDR Artifacts in light sources

              • 4. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
                3perf Level 1

                Are you suggesting that the 3 stop bracketing is responsible for LR's complete failure at applying any deghosting? That would be a pity, because everything else about the merge worked out very nicely. What do you consider a reasonable bracketing step?

                I bracketed using shutter speed, not aperture.

                 

                If LR's Merge to HDR can't deal with small changes from one image to another, that's pretty disappointing. I could understand artefacts on large changes...

                • 5. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
                  JimHess Adobe Community Professional & MVP

                  Adobe has suggested that better results can be obtained using just two images. I have done two and three image HDR merges using Lightroom, and haven't been able to see any real difference. I think two f-stops is probably a more realistic difference. However, your experience might be different than mine.

                  • 6. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
                    3perf Level 1

                    Thanks @JimHess, I'll try a few 2EV things and two-image HDRs. Does deghosting work for you?

                    • 7. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
                      JimHess Adobe Community Professional & MVP

                      I don't know. I haven't had an issue so far.

                      • 8. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
                        trshaner Adobe Community Professional & MVP

                        3perf wrote:

                         

                        Thanks @JimHess, I'll try a few 2EV things and two-image HDRs. Does deghosting work for you?

                        I suggest shooting at least three 2EV bracketed images ( -2, 0, +2) and then trying both two and three image HDRs. Using three or more images will reduce noise and may help with some deghosting issues. Most cameras have an auto-bracket mode that can be set to shoot three or even five images.

                         

                        Tips for Creating Raw HDR Images in Lightroom CC « Julieanne Kost's Blog

                        • 9. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
                          ssprengel Adobe Community Professional & MVP

                          After seeing your originals, the issue, to me, looks like the leaves are smaller or skinnier in the brightest image, due to either focus issues or just lens blooming, so there's no way to get those green leaves overlaid on either of the images with clouds and silhouetted leaves without some of the less-skinny black silhouettes or blown sky showing which is exactly what is there, white and black halos around the leaves.  In other words without the green leaves being the same size as the black silhouettes there's no chance in getting a good blend.  You could try doing an HDR of the two darker images and see what happens, but it won't have green leaves.

                           

                          If you had done more shots closer together in exposure then it might have been possible to choose the darkest image with some color in the leaves and another image that showed silhouetted clouds and been ok as long as the leaves were the same size and hadn't moved between the two shots which would require entirely calm weather.

                          • 10. Re: HDR Merge: Deghosting doesn't seen to work on Canon RAW images?
                            3perf Level 1

                            Correct -- lots of blooming due to the foreground leaves being so out of focus -- combined with the strong overexposure. It turns out LR can merge the two darker images practically artefact-free, which was a pleasant surprise.

                             

                            I just played around a little with the 32bit merges done by Photomatix -- though HDRSoft often seem to be better at deghosting images, LR is (arguably) doing a nicer job of contrast, colours and lowlight/highlight detail. That's when putting both the LR and Photomatix merges through LR tone mapping. Makes sense, considering that LR has such solid, well-working colour science.