Written by Peter Tellone
Photographer and Topaz user Peter shares with us some helpful tips on how to prevent noise.
Low ISO: First and foremost; we should try to shoot at the lowest ISO possible for our situation. If you can open up your aperture without affecting the DOF you are trying to achieve rather than increase ISO, do that. Slower shutter speeds that still stop the motion we may have or are within the speed that we can hand-hold without showing camera shake then do that. If you can’t handhold and are not shooting a moving object then consider using a tripod instead of raising the ISO.
Expose Correctly: Secondly: Expose your scene correctly and as best you can. Underexposing will increase noise, so getting a correct or slightly over exposed image will make all the difference in the world. The best way to know is to check your histogram. If you see most of your histogram bunched up to the left and very few pixels or a big gap on the right, you probably are underexposed.
As I talked about earlier, some photographers like to “shoot to the right” which involves slightly over exposing their images and pushing the curve in the histogram more towards the right hand side. Just don’t go too far and clip your highlight because you may loose detail which can be worse then the noise you are trying to prevent. After someone has shot to the right, usually in post they will bring that luminance range down and take with it noise.
Edit with a light touch: Watch your editing. If you have an image that is slightly noisy to begin with or even if you don’t, you can increase and exaggerate that noise by excessive editing and manipulating the lightness values and color values of your image. So try not to push Levels or Curves too far or even the saturation beyond what the image needs.
If you are taking some big swings to give an image Pop or Punch, then consider where in the process you are making those adjustments. If you shoot RAW rather than JPEGs you are at an advantage because in most case in a RAW editor that is not pixel editing you can push things further without some of the side effects you will get if you try to make those adjustments in a Pixel editing program.
Crop reasonably: Also watch how much you crop an image, if you crop too many pixels out of an image we essentially magnify the image and it may make the noise more visible in the image.
For JPEG compression noise, Always save files with the least amount of compression, (Photoshop 10+) or consider using a file format like Tiff or PSDs that are not subject to lossy compression noise.
For long exposure noise, consider turning on the long Exposure Noise Reduction available in the custom menu of better DSLRs.