-1

This question already has an answer here:

Even on a 5D ISO noise is a challenge. I use PS raw photoshop and Adobe Bridge. I want to minimise loss of image quality.

marked as duplicate by scottbb, inkista, AJ Henderson Aug 16 '17 at 15:19

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • 1
    there are probably several answers on this site already. Look at the 'Related' list on the right hand side of your question – laurencemadill Aug 9 '17 at 13:56
  • 2
    The use of the word "minimise" seems to imply you believe there is a magic recipe that will result in the smallest possible loss of "image quality" (however you define that). I don't think that's the case. – user29608 Aug 9 '17 at 22:53
2

What is the best way to reduce high ISO noise?

Put more light on the subject when you shoot it.

Noise is not a property of a specific ISO, it is a property of the Signal-to-noise ratio. By increasing the signal (adding more light) you can reduce the exposure which also reduces the influence of noise by increasing the signal-to-noise ratio.

Image info: ISO 3200, f/2.8, 1/1600 second. The subject was bathed in the bright light from a spotlight.

enter image description here

Same set, same camera and lens (although at 70mm instead of 200mm). ISO 3200, f/2.8, 1/320 second. The subject was on a much darker part of the stage. Even with the 2 1/3 stops slower shutter speed there's still less light entering the camera and the image is noisier. Using more aggressive noise reduction reduced the fine detail in the image.

enter image description here

0

I believe noise will always be a problem, however using Adobe Lightroom's noise reduction slider can reduce noise quite well while retaining a fair amount of sharpness and quality.

0

When taking pictures of static objects (buildings, landscapes) you can use image stacking. By taking many pictures, aligning them and averaging over the aligned images, you'll average out the noise. Noise reduction should then be turned off, as that will allow details that are hidden under the noise floor to emerge. Noise reduction should be applied after averaging over the pictures.

When shooting under dark conditions the long exposure noise reduction should be enabled, as this performs a dark-frame subtraction, removing the hot pixels. Taking one dark-frame exposure yourself to use that multiple times to save time is a bad practice, because the dark-frame will itself contain noise that you want to average out as well.

Each picture should be taken by the "exposing to the right" method. Here you expose to the limit where you just avoid overexposure. In post processing you can then reduce the exposure which then reduces the noise. E.g. suppose that by exposing to the right you can increase the exposure by 2 stops. This will then reduce the noise by a factor of 4 in each picture. If you take 25 pictures and average over them, then that will reduce the noise by a factor of square root of 25 = 5. So, you can reduce the noise by a factor of 4*5 = 20 just by taking the effort to take more than one picture and exposing for longer.

  • If one has to use high ISO, then ETTR is obviously not an option. If you could open wider or use a longer exposure, you'd do that in the first place, so ETTR just means... even higher ISO. – user29608 Aug 10 '17 at 5:36
  • @fkraiem That depends, e.g. if you shoot at night using a tripod, you may want to shoot with exposure times of the order of seconds instead of tens of seconds for various reasons (e.g. you don't want star trails in astrophotography). This then leads to an ISO of, say, 3200 or 6400, but not 100. ETTR is meaningful under those circumstances, when shooting at a fixed exposure time (say 1 second), you're going to get a lot less noise when shooting at ISO 6400 than at ISO 100. – Count Iblis Aug 10 '17 at 21:24

Not the answer you're looking for? Browse other questions tagged or ask your own question.