10 Replies Latest reply on Mar 11, 2008 11:21 PM by Ramón G Castañeda

    What's causing this problem??

      If you look at the photo http://i90.photobucket.com/albums/k263/muratc/3074534401211243520.jpg?t=1205165499

      you'll see that I'm having serious problems in the sky. I don't know what this is called but there are color shifts, blotches, banding, abrupt tonal cahnges, etc. The original size TIFF looks quite good but when I resize, convert and save as JPEG to upload on a web page, it looks terrible. This has started recently and happens usually to the blue skies.

      I haven't changed my workflow lately but here is what I usually do.

      - Always shoot RAW and process with ACR
      - I do the usual adjustments in ACR...Exp, WB, Black, Clarity, Sat, etc
      - RAW is processed at 16bit, ProPhotoRGB, 300dpi
      - Image is opened in PS and converted to AdobeRGB
      - Usual adjustments and tweaking in PS, nothing extermely radical
      - Saved as TIFF or PSD in 16bit
      - All the images have no problems as seen in the above photo

      Then when I wish to upload an image to a website
      - First I resize it to a smaller size using bicubic sharper
      - Then I convert the color space from AdobeRGB to sRGB
      - Then I convert the image to 8-bits to save as JPEG
      - Finally I save as JPEG at Max. quality Format options: Baseline Standart

      Not all but most images with skies like this look this way. What am I doing wrong here? In the color settings, conversion options, AdobeACE is selected as the engine, Intent is relative colorimetric, Use Dither and Use Black point comp. is selected. Anything wrong here?

      Any help, any suggestion will be greatly appreciated

      Thank You
        • 1. Re: What's causing this problem??
          Ramón G Castañeda Level 4
          Murat,

          The sky on your (untagged) image looks just fine on my machine, if a bit too dark. Are you sure your monitor is correctly calibrated and profiled? From your description, one might even conclude you're not even set to Millions of Colors.
          • 2. Re: What's causing this problem??
            Level 1
            Aside from a bunch of nasty looking jpeg artifacts, I don't see anything wrong with this file. Like Ramon, I notice that it's untagged - probably a screen shot. I assigned a generic LCD RGB profile to it, then converted to Adobe98 and was able to edit the file satisfactorily.

            Perhaps the file is good, you're just not looking at it properly. Bad monitor profile?
            • 3. Re: What's causing this problem??
              (Marco_Ugolini) Level 1
              My hunch is that Murat's monitor (an Apple Cinema Display, perhaps?) may have burned-in areas, which make the image look streaked and separated into lighter and darker sections, depending on which images got burned into the display area. I've seen this problem lately on several monitors, possibly caused by cheaper materials and reduced quality controls.

              I would suggest to Murat that he look at his file on someone else's monitor, and see if he can detect there the same problems as he finds in his system. Like the others who have replied before me, I cannot see on my monitor the problems described by Murat.
              • 4. Re: What's causing this problem??
                Tim Lookingbill Level 1
                Photobucket as do many other image hosting sites may be adding additional compression upon upload to their site.

                I see the blotchiness in the sky. It's quite subtle though. If it looks good in ACR and Photoshop and other apps before saving to jpeg then it's a compression problem compounded with you saving as a jpeg and uploading to PhotoBucket.

                Just my guess.
                • 5. Re: What's causing this problem??
                  Gusgsm Level 2
                  I see the blotches too and they are noticeable, specially in the middle tones of the sky.

                  I think the trouble is in the process of jpeg compression.
                  • 6. Re: What's causing this problem??
                    John Danek Level 4
                    The sample looks way too dark ( gray snow, gray/blue sky ). You're probably in good shape while in ProPhoto 16bit RGB, but I believe you're clipping the image...especially for web. Try saving a copy of the original and, instead of converting to Adobe RGB / Relative Colorimetric, keep both images in ProPhoto / Perceptual. So, you now have two files: 1.) 300ppi, and 1.) 72ppi...one for print, one for web. But, the difference is they are both still 16bit from the original RAW file. Now, for the print version, convert to Adobe RGB / 8bit / 300ppi. For the web version, size it to whatever you need for display at 100% no scaling, no additional compression, no more resizing. Convert the web version to sRGB / 8bit / .jpg @ 4 ( no need to save at a higher compression ). By keeping the rendering in "Perceptual", you may retain more gamut than an Adobe RGB / Relative Colorimetric. Try a generic test on one of your "problem" images and see if there is an improvement. Some of the other posts regarding your monitor may be another issue ( banding, splotches, etc. ).
                    • 7. Re: What's causing this problem??
                      John Danek Level 4
                      Followup. I just opened the image in PS. I agree with some of the previous posts, it looks as though the image has been re-compressed. I havn't seen artifacts that big unless the image has been enlarged from a smaller compressed version. Not much you can do unless you download the images and apply a gaussian blur or airbrush the artifacts and then re-upload to replace the existing.
                      • 8. Re: What's causing this problem??
                        Level 1
                        Thank you for all the replies. First my monitor is quite OK and there are no problems with it. I'm using a NEC Spectraview Reference monitir and it's frequently calibrated.

                        It may be true that some websites force additional compression as they look worse when I view them after uploading. But I'm having this problem even when I view them on the calibrated monitor right after I convert and save them JPEG's with the above mentioned method. When I try to convert/save them with "Save for Web" in the PS, the problems are not there. It's quite weird, I suspect there is something wrong with my workflow.

                        How about this "Use Dither" in the conversion options? Does it make a difference?
                        • 9. Re: What's causing this problem??
                          Tim Lookingbill Level 1
                          Yes, have "Use Dither" turned on in the convert to dialog box and in Color Settings. It does make a difference.

                          To see this make two copies and convert one with it on and the other off and zoom in on each and compare how it affects broad gradients like your blue sky.

                          Jpeg compression will compound the appearance of blotches in these areas and dithering busts them up by adding a small amount of monochrome type noise so they don't stick out.

                          Of course convert first before the final saving to jpeg.
                          • 10. Re: What's causing this problem??
                            Ramón G Castañeda Level 4
                            Another thing worth mentioning is that by reducing the resolution of my monitor to a mere 1024x768, the image posted by Murat displays large enough to see the "blotches", which do look like typical JPEG compression artifacts.