8 Replies Latest reply on Apr 22, 2009 12:18 PM by Ramón G Castañeda

    Are highlight and shadow clipping must be avoided in any image?

    chlonini

      Are highlight and shadow clipping must be avoided in any image?

      Because in some cases, let's say, night scene, usually has many black pixels in the sky. Which perform nice contrast against the colorful signs.

      Please check the attached image for reference(01.tif).

      I know there's nothing in the sky, so I would like to keep all the pixels to be clipped. Is this right?

       

      Some of my students says that other instructors told them to keep all the pixels in the histogram.

      But I tell them it depands on how would you like your images to show. Am I correct?

      As the attached image, it's impossible to pull the black pixels back to the histogram and I think it's acceptable in this case.

       

      Let's see the 2nd case(02.tif), this image has highlight clipping in the clouds.

      I like the way this image looks, which looks like a watercolor painting.

      If I pull the white pixels back, the image will change a lot and I will get a very dark overall.

       

      My question is, is it that important to keep your images without having highlight or shadow clipping?

      This is not apply to any image, right???

       

       

      THANK YOU

        • 1. Re: Are highlight and shadow clipping must be avoided in any image?
          MadManChan2000 Adobe Employee

          No hard and fast rule here. You do what's necessary to make the image look good. Sometimes it's very nice to have areas of solid black in the image. That's where the Blacks slider comes into play. Same goes with highlights -- only you can determine what's important highlight detail and what's ok to let go to white. Optimize for what makes the image look good, not for what the rules say.

          • 2. Re: Are highlight and shadow clipping must be avoided in any image?
            w3jxp-V4L7UU Level 1

            What MadMan said! Rules are made to be broken. One problem some have is a feeling that there is some hidden rules that will automatically make your photography "perfect". The truth is the rules don't exist. They are some like the "rule of thirds" that can be useful but not in every photo.

            I for one clip the shadows in a lot of my photographs. I like inky black and that is one way of getting it. See that attached photo.

             

             

            John Passaneau

             

            (Quartz with Rutile inclusons, Brazil)

            1 person found this helpful
            • 3. Re: Are highlight and shadow clipping must be avoided in any image?
              Ramón G Castañeda Level 4

              John,

               

              If you use the camera icon in the formatting bar above the reply box in the forums to embed your image in the post itself, it will appear instantly.

               

              When you send an image as an attachment,  it gets queued first to be scanned for viruses/virii, so it takes a while for it to appear.  Then, once approved, you get just a tiny thumbnail that you must click on to see the image, and it will take forever to open.

               

               

              Camera-icon-in-reply-box.jpg

              • 4. Re: Are highlight and shadow clipping must be avoided in any image?
                Bill_Janes Level 2

                For a more in depth discussion of clipping, it should be noted that clipping can occur in either the raw file or the rendered white balanced file. In the latter, it can take the form of luminosity clipping or saturation clipping. Saturation clipping occurs when the chosen color space is too small to accommodate saturated colors at a high luminance. In ACR, saturation clipping is indicated by a colored line or shoulder at the right of the histogram. The remedy is to use a larger color space. Luminosity clipping in ACR is indicated by a white line or shoulder at the right of the histogram and the remedy is to adjust exposure or use highlight recovery.

                 

                Examination of the OP's histogram shows a yellow line at the right, indicative of saturation clipping of the red and green channels. The OP could try a wider space such as ProPhotoRGB.

                 

                Here is an image of a a flower rendered into sRGB using the ACR defaults and the Adobe Standard camera profile. It appears overexposed and the yellows (actually reds and greens) are clipped as indicated by the yellow line at the right of the histogram.

                 

                 

                10_sRGB_clipping_DEFAULTS.png

                 

                The raw histogram (produced by Rawnalize) shows that the image is well exposed. The red and green channels are just short of clipping. The image appears overexposed with ACR, since ACR uses a baseline exposure offset for the Nikon D3.

                 

                010_Photobola.png

                 

                 

                However, when white balance is applied for this daylight exposure, the red channel is multiplied by approximately 2.21, and this should result in clipping of the red channel. This did not work exactly as expected with ACR, so I used Iris (a freeware astronomical program which allows extensive control of the conversion process) and examined the histogram of the resulting image in Photoshop. Note that the green channel is just short of clipping, as expected and that the red channel is clipped.

                 

                IrisHistogram.png

                 

                To avoid clipping with the white balance in ACR, it is necessary to use negative exposure to offset the red white balance multiplier. I chose to use a bit of highlight recovery as well to tone down the highlights while maintaining a pleasing value for the midtones. Here is the resulting preview with rendering into ProPhotoRGB.

                 

                 

                10_ProPhoto_clipping_FINAL.png

                 

                In this case, I was able to avoid clipping. However, when the image is printed or viewed on a display with a limited gamut, some clipping would undoubtedly occur.

                • 5. Re: Are highlight and shadow clipping must be avoided in any image?
                  Bill_Janes Level 2

                  Ramon,

                   

                  I posted some embedded photos in this thread. Initially, they worked properly, but now they don't. I don't know what is going on, but I did note your earlier statement that the new forum format had some problems.

                   

                  Bill

                  • 6. Re: Are highlight and shadow clipping must be avoided in any image?
                    Ramón G Castañeda Level 4

                    Bill_Janes wrote:

                     

                    I posted some embedded photos in this thread. Initially, they worked properly, but now they don't. I don't know what is going on, but I did note your earlier statement that the new forum format had some problems.

                     

                    Bill,

                     

                    These new forums are a POS.

                     

                    Just to clarify:  did you use the camera icon in the formatting bar of the reply box and then use the "From your Computer" tab as opposed as "From the Web"?  The latter doesn't work in the long run, it eventually turns the images into dead links.

                     

                     

                    Camera-icon-in-reply-box.jpg

                     

                    Do not use "Uploaded Images" or "From the Web" tabs!

                     

                    Adobe_forums_Insert_Image.jpg

                     

                    Message was edited by: Ramón G Castañeda

                    • 7. Re: Are highlight and shadow clipping must be avoided in any image?
                      Bill_Janes Level 2

                      Ramon,

                       

                      Thanks for the illustrated reply. I did use the camera icon and the From YourComputer tab. The images worked for a couple of days and then died. I thought that I had posted some useful information, but my effort was futile. No wonder that the traffic in these fora is sparse. I hope that Adobe addresses some of these issues.

                       

                      Bill

                      • 8. Re: Are highlight and shadow clipping must be avoided in any image?
                        Ramón G Castañeda Level 4

                        Bill,

                         

                        There seems to be just no end to the many ways in which this POS forum software mangles posts.