11 Replies Latest reply on Nov 29, 2009 11:11 AM by Panoholic

    Camera RAW pixel artifact issue

    GrootLensDude Level 1

      This is something that has been bothering me for a while and I don't understand how other people don't see it.. Mainly due to the fact that you need to be zoomed in about 300% or more on an image to see it. I have only seen Lightroom 3 rendered jpeg files without this problem. I am talking about the absurdly weird artifacts in the pixel makeup when zoomed in on a edited image rendered by Adobe Camera raw 5.6 and lower. It looks like worms have been moving around under all the pixels. It is not a clean and definate pixel noise ratio that you would get from rendering images from their native software for example ViewNX, Capture NX nor Canon's DPP.

        • 1. Re: Camera RAW pixel artifact issue
          Panoholic Level 2

          1. Do you see the worms in LR/ACR too, in this magnification, or only in the JPEG version?

           

          2. Do you see them in a TIFF as well?

           

          3. If they are not there in TIFF: create a JPEG from the TIFF. I guess LR too has a "preview" option, showing the effect of conversion in the image in the currently displayed magnification. Change the "quality" setting and watch for the effect (you have to wait a bit to see the effect of the change). If I do this in CS3, the worms are there up to quality 8, most of them vanish with 9 and it is clean from 10.

           

          If the worms are visible already during the raw processing, i.e. in LR/ACR, then it is a different issue, probably camera dependent.

           

           

          Gabor

          • 2. Re: Camera RAW pixel artifact issue
            GrootLensDude Level 1

            Its not the quality saving option that is the issue, I always save at quality level 10 or higher except if Im sending proofs. Thsi has to do with the output file through ACR ..

             

            The attached file show what I am referring to, this file is a 100% zoomed in at 500% and I made a mistake, the left should be ACR 5.2 not ACR 4.5.

            • 3. Re: Camera RAW pixel artifact issue
              Avery Foto

              I have a similar issue. I sat up my D300 up on a tripod and shot the same picture a few times, one non-compressed and one lossless and brought them into LR 2.5 as dng and nef. The full nef was 25mb, in-camera lossless was 15mb, The 25mb nef also converted into a 15mb lossless dng and then the fun started. The 15mb in-camera lossess converted into a 15.3mb dng and the extra 300k is trash. At 300% what should be a black line of pixels is now twice as wide and has about 3 pixels of red halo down each side. I'm seeing it in lossless nef to lossless dng conversions. If It renders the nef's correctly in CS4 and LR2.5 in the first place, why does it screw up the conversion too dng?  Is this what your seeing? As a Nikon shooter, I'm not going for the dng thing until it's unquestionably perfected.

              • 4. Re: Camera RAW pixel artifact issue
                GrootLensDude Level 1

                To Avery: I never ever convert to DNG, just that one more loop hole to jump through in my processing scheme and it's one too many, I usually just get the file corrected then convert straight to JPEG, then I delete the NEF once Im done and happy, it takes up way too much space. The thing is, I usually shoot JPEG cause the Nikon system renders in camera jpegs so really really good but now and again the auto WB just does not work or the lighting situation is so diverse and I need to shoot fast that I dont have the time to shoot JPEG, so I need RAW for those circumstances so that I can get a clean jpeg later on but then I have to edit in ViewNX to not get those stupid artifacts..

                • 5. Re: Camera RAW pixel artifact issue
                  Avery Foto Level 1

                  Totally agree about Nikon's in camera jpgs, I really only shoot raw at high iso. I am assuming that Adobe uses the same code for camera raw as nef to dng conversions. I tried it and found degradation in my files, different, but yet the same. What's funny is the fact that I always look for an answer and wonder why no one else can see it. Luckly, I'm not having a problem with nef's in CS4 or LR so I can just skip the dngs and go on. Personally I hate the Nikon software.

                  • 6. Re: Camera RAW pixel artifact issue
                    Jeff Schewe Level 5

                    GrootLensDude wrote:

                     

                    The attached file show what I am referring to, this file is a 100% zoomed in at 500% and I made a mistake, the left should be ACR 5.2 not ACR 4.5.

                     

                    You realize what you are seeing at that zoom level is science fiction, right? It doesn't relate to anything real...

                     

                    At a 500% zoom, based on a display that is maybe 100 pixels per inch, you are seeing your image blown up five times reality...

                     

                    If the end result is a print, you will NEVER see the noise signature at ANYTHING near this size and detail. Point of fact, the ACR image will definitaley

                    print better because the real image detail–the edges–are better defined because the noise is reduced in the image.

                     

                    The DPP image is far noisier and will be more prone to problems down the road...

                     

                    If you "think" you like that noisier image better (and for print, your really, really shouldn't) you might take a look at Lightroom 3's beta...it actually has a noise addition capability to satisfy people who seem to want that sort of look. Of course, the fact it's optional means you aren't locked into the look (and it's adjustable to taste).

                    • 7. Re: Camera RAW pixel artifact issue
                      GrootLensDude Level 1

                      Jeff, I come from the film shooting era, and I was used to what a film looked like scanned in, I love that grainy feel and ACR just doesn't give me that. And as I remembered film used to print REALLY well

                       

                      (and I do see that effect at a 100% zoom level, I posted the zoomed in pic to point it out more clearly..)

                      • 8. Re: Camera RAW pixel artifact issue
                        Jeff Schewe Level 5

                        So...test Lightroom 3 beta (and the grain addition capability)...

                         

                        But, beware, even ad 100% zoom you are seeing your image 3 TIMES reality based on 300PPI print output...

                         

                        You really need to understand what you are and are not seeing when at various zooms in Photoshop. The zoom that more closely resembles reality is 25% for ink jet prints although the problem, there is that the display is still 1/4 to 1/3 the resolution of the print...

                         

                        Really, film grain in scanned film is not a reliable guide to what digital capture should look like...

                        • 9. Re: Camera RAW pixel artifact issue
                          GrootLensDude Level 1

                          Oh I know exactly what I ashould be seeing, been doing digital work for over 10years. I know what high end drum scans, Nikon Coolscans, Fuji frontier and Agfa scans looks like. What digital grain looked like on the first Canon D30 and 10D upto the newest cameras look like. Your missing what I am saying..

                           

                          I am referring to ACR 5.6 and lower's inability to correctly render RAW files. I said that (if you read my first post) Lightroom 3 surprised me in the fact that it rendered the files correctly with no weird artifacts, so it's telling me that Adobe is going into the right direction with ACR 6. When looking what the files should look like I will trust the camera manufactures software over any other third party software any time of the day

                          • 10. Re: Camera RAW pixel artifact issue
                            Panoholic Level 2

                            This artifact is the creature of the demosaicing algorythm. I have seen much worse with certain cameras, when the sensor's green channels had different gains. I don't know if the difference is the result of a different demosaicing algorythm in the newest version, or of the different interpretation of the raw data. For example the Canon 7D's preliminary support created such artifacts, and now the final support makes it much better, even with the very same version of ACR.

                             

                             

                            Gabor

                            • 11. Re: Camera RAW pixel artifact issue
                              Panoholic Level 2
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                              Avery Foto wrote:

                               

                                     The 15mb in-camera lossess converted into a 15.3mb dng and the extra 300k is trash. At 300% what should be a black line of pixels is now twice as wide and has about 3 pixels of red halo down each side. I'm seeing it in lossless nef to lossless dng conversions. If It renders the nef's correctly in CS4 and LR2.5 in the first place, why does it screw up the conversion too dng?  Is this what your seeing? As a Nikon shooter, I'm not going for the dng thing until it's unquestionably perfected.


                              1. What is "trash" in the raw file in your concept?

                               

                              2. Can you upload the NEF file (the losslessly compressed one)? (Use yousendit.com if you don't have web space; you don't need any registration; post the URL for the downloading here.)

                               

                              3. There are not many reasons to convert the NEF in DNG: if your LR/ACR does not support your camera and you want to avoid the upgrade, or if you want to record the adjustments in the raw file instead of the sidecar .XMP

                               

                              Gabor