You have been using a digital camera for quite some time. You no longer have a film camera and if you are a 3rd generation teenager you may not even know what a film camera is! Almost any digital camera (even a $100 digital camera) takes better photograph than a film camera did 25 years ago. However, Noise is and was always a problem with all cameras – whether digital or a film camera. Noise is the grainy, dusty and dotted stuff that you see on your computer in a digital photo that you took with your camera. Noise reduces the beauty of a photo. What causes Noise and what can be done to control it?

The most important factor that increases Noise in photos is high ISO. ISO is a measure of your camera sensor’s (or film’s) sensitivity to light. Most of the digital cameras let you increase the ISO for shooting in low light. Photos will always have some noise, but the higher you set the ISO, the more the noise.

Long exposures also produce noise in photos. The longer the exposure, the hotter your camera sensor gets, and heat contributes to noise. In daylight photography this is not a problem but longer exposures at night can cause noise. Another factor is under exposure. You will generally see more noise in darker areas and in images that are underexposed. It gets more noticeable when you enhance an underexposed photo, so having the right exposure when you take the picture is important.

Avoiding Noise

Though low ISO settings give you the least noise you cant be at ISO 100 or ISO 200 all the time. In brighter surroundings even higher ISOs do not create problems. But if you are shooting indoors without a flash at lower ISO settings then the photos will not turn out right, so you will be forced to increase the ISO to 800 or even 1600. Here remember to not increase the ISO to 1600 if ISO 800 will do. The noise at ISO 1600 will always be very high. Increase the ISO until the shutter speed is fast enough to take a sharp photo, usually about the inverse of the focal length. If you have the lens set to, say, 100mm, you can get a fairly steady shot with a shutter speed of 1/100 second. Also remember to reset the ISO to the lowest setting after you are finished shooting in low light with high ISO. Don’t leave it in Auto mode as the camera can choose its own ISO which is usually higher than what is required. I found that whenever I leave the ISO in Auto mode (on my Fuji Finepix) it unnecessarily jacked up the ISO in slightly darker conditions.

For longer exposures try turning on noise reduction (if your camera has the feature). In many cameras the feature automatically activates when the shutter speed exceeds 1 second. The thing is that both underexposed and overexposed photos have their own problems with noise.

You can also use a photo editing software to reduce noise. Most photo-editing softwares come with a noise reduction filter. You can also try standalone dedicated programs like Noiseware or Noise Ninja.

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