3 Replies Latest reply on Aug 18, 2015 11:10 PM by bwallan007

    Rendering of Sony A7r II files seems to create noise and hot pixels in the shadows

    dennisberggren

      I did a couple of basic tests regarding hot pixels etc on the A7r II. Last week when I was out trying the camera I was out shooting the night sky. When developing the images I was a bit surpised to see colour noise in the shadows of the images. It was really dark outside so the images where captured at ISO 1600 and 20 seconds exposure time.

       

      After reading about it I read at a blog (sorry, can't remember which) that it might be an issue with Lightroom's ability to develop the raw files from the A7r II camera. So I did a simple test by developing the same file in Lightroom and Capture One for Sony. All I did in Capture One was to turn on Lens Correction and then export a TIFF file. I then exported that file and imported into Lightroom. In Lightroom I applied the same development settings as the Lightroom imported raw file. I needed to do some minor tweaks because it seems that the different engines do render the RAW files differently.

       

      I placed jpeg exports in an album on Flickr at:

      https://www.flickr.com/photos/dennisberggren/albums/72157657375046792

       

      I also include low res jpegs and screen dumps of the lower left corner of the image so you can see the difference.

       

      For me, being an amateur, the diference is day and night! I am surprised to see such a big difference in the rendering of the shadows.

       

      CaptureOneDeveloped.png

      LightroomDeveloped.png

      Please feel free to see what you can find. For me it seems that Lightroom Import do add noise into the shadows of the RAW files of the Sony A7r II.

        • 1. Re: Rendering of Sony A7r II files seems to create noise and hot pixels in the shadows
          bwallan007 Level 1

          I've shot  a fair number of nightscapes w/ the A7R II and guess I don't see the same problem, if there is a problem?  I looked at both your images.  Yes, they're different but I can't tell which one is the best of the two.  It could simply be a matter of processing?

          bwa

          • 2. Re: Rendering of Sony A7r II files seems to create noise and hot pixels in the shadows
            ssprengel Adobe Community Professional & MVP

            There are many small-or-single-pixel white and other-colored spots on the LR version, and no white spots on the C1 version.

             

            Here is a side-by-side of the same lower-left area of each.  There is clearly some noise-reduction being applied in C1 that isn't in LR and/or LR is sharpening and C1 isn't.

             

            It might be wise to share the ARW and the TIF here for others to examine.  Upload to www.dropbox.com and post a public share link, here.

             

            If I took this sort of shot with my Canon 7D Mark II, I'd have long-exposure NR on, which would take a second shot of identical duration and ISO but with the shutter closed, and then subtract this from the original raw.  This tends to get rid of the fixed, single-pixel noise--the tiny spots.  Does C1 have access to the camera's hot-pixel map?

            • 3. Re: Rendering of Sony A7r II files seems to create noise and hot pixels in the shadows
              bwallan007 Level 1

              Looking at your full sized comparison image, it is quite obvious Capture One is applying some noise reduction.  Not only is it removing hot/cold pixels it is also smearing/removing detail!  I would say Lightroom is the most honest image coming out of the camera even though it has some noise...

               

              I do agree with the use of long exposure noise reduction (LENR) in this instance or actually shooting a dark for subtraction.

               

              I'm not really surprised to see hot/cold pixels in images off any camera.  As part of my initial testing of the A7R II I shot 30 second dark subs at ISO's 100, 400, 800, 1600, 3200, 6400, 12800, 25600, 51200 & 102400 for noise evaluation in PixInsight.  I definitely saw a few hot/cold pixels in all the images but don't consider it all that serious a problem.  It looks very similar to the noise in images off the A7S, A7R and A7 II, as well as my Canon DSLR's...  The use of dark subs or LENR pretty much eliminates the problem.  I use all the cameras for astro/nightscape photography with no major concerns as to image quality.  The A7R II is very similar in this regard to the A7R.

               

              bwa