PHOTOGRAPHER’S TUTORIAL

2. Image quality requirements

2.3. Color noise

Appearance of color noise on images can spoil even the best subject. It is necessary to prevent it during a shooting, and in cases where it appears in photos, use a software program to reduce it.

Color noise appears in images as relatively small, randomly situated defective pixels, with variation in hue. Heavy and distinct noise decreases the quality of an image, drawing spectator’s attention away (especially if situated on uniform color areas) and giving an unrealistic look.

Main sources of noise are: bad quality of digital sensors (cheap cameras produce more noise), very long exposure times, as well as algorithms of processing a signal from sensor by camera.

Preventive measures are: usage of normal and short exposure times and moderate ISO numbers. The longer an exposure time, during which photons of light affect camera sensors, more “hot” pixels will appear. Noise tends to appear at a shot underexposure and efforts can be made to pull it off later in a graphic editor.

In case of poor illumination of a subject, choose shooting in a RAW camera format in order to lessen the noise level at post processing.

Do Submit:

The original image

The image is ok, we are glad to accept it!

Do NOT Submit:

An attempt of exposure correction

Appearance of noise

Do Submit:

Regular JPEG compressionе

The image is ok, we are glad to accept it!

Do NOT Submit:

Excessive JPEG compression

Loss of details, appearance of artifacts

Use specially developed software to decrease noise with caution, since their abuse can greatly decrease the quality of the image which will result in losing details, focus and blurring.