7 Replies Latest reply on Aug 30, 2016 1:21 PM by Abambo

    Noise Reduction

    southwestform Level 1

      I have some photos taken with low light so there was noise/grain on the photo. I adjusted the Noise Reduction settings and it seemed to make an improvement. This had me wondering, is there a downside to using the Noise Reduction options? Does it have any effect on overall quality? Does it affect the quality of a print?

       

      Thanks.

        • 1. Re: Noise Reduction
          Jao vdL Adobe Community Professional & MVP

          Make sure you only adjust the noise reduction when zoomed in to 1:1. In the zoomed out view the preview in Develop is not adequate to judge it. If you zoom in you will immediately notice the loss of quality - mainly you lose detail) that is inherent in noise reduction. Smart use of the sliders will minimize this. So this is very much something that needs to be optimized and strongly depends on the nature of the image. If you have vast expanses with little detail you can generally dial in more aggressive noise reduction than when you have lots of very fine detail that needs to be preserved.

           

          Whether it affects prints depends mostly on the size of your print. You'd be surprised how much noise in a picture on the screen disappears in print.

          1 person found this helpful
          • 2. Re: Noise Reduction
            ssprengel Adobe Community Professional & MVP

            Removing noise also removes fine detail that is indistinguishable from the noise so you can end up with a plastic-looking image.  It really depends on the subject, what amount of noise and noise-reduction is acceptable.

            2 people found this helpful
            • 3. Re: Noise Reduction
              southwestform Level 1

              Why does the noise that appears in a photo on screen disappear in print?

               

              Thanks.

              • 4. Re: Noise Reduction
                ManiacJoe Adobe Community Professional

                When an image is made smaller, either physically smaller to fit a screen or visually smaller when printed, the process of reducing the large number of pixels to a smaller number of pixels naturally eats much of the noise due to the averaging of the data values (a gross over-simplification).

                 

                You should keep this in mind when working with the noise reduction sliders. Viewing at 100% is good for working with the sliders to see what is being done. However, viewing the image afterwards at 50% or even 35% is often more accurate representation for what your family and friends will see/print. This will lead you to using much lower noise reduction values than you think.

                • 5. Re: Noise Reduction
                  JimHess Adobe Community Professional & MVP

                  I agree with that observation. It seems that many users become obsessed with noise and with sharpness, and tend to overuse both of these features.

                  • 6. Re: Noise Reduction
                    Conrad C Adobe Community Professional & MVP

                    What you're looking for is the right balance point between noise reduction and sharpness. If a picture is noisy, you have to apply noise reduction, but when you start to see details being wiped out it's time to back off on the noise reduction amount. The same works in reverse for sharpening: Many images need sharpening, but if you apply too much sharpening to a noisy image, you'll end up sharpening the noise.

                     

                    When you don't overdo it, both noise reduction and sharpening improve an image. When you overdo either, the image can look artificial. Both can improve images for screen and print, but the correct amount of sharpening is different for screen resolutions than print resolutions.

                    • 7. Re: Noise Reduction
                      Abambo Level 4

                      A simple test to do: push the noise reduction to the max an see what effect it has on the (fine) details In your image.

                       

                      Fine details and noise have similar properties, but the one is loved and the other is dissmissed.

                       

                      You need to undestand the eye and the human vision before reducing noise:

                      Colour noise is badly acepted, but easily reduced. Luminance noise is not that bad and accepted if if is uniform. Indeed, I added sometimes noise to my pictures to fool the observers eye. Uniform noise is quite nice, therefore you have all those strange sliders like add noise, add vignetting etc. All faults... to make pictures worse, but look better!

                      1 person found this helpful