HOW NOISY IS YOUR CAMERA?
Want to eliminate that grainy look in your photos? Hans Weichselbaum runs you through the causes of noise in your images and how to make it go away
No, by ‘noise’ I don’t mean the annoying click your DSLR makes when you shoot in a quiet concert hall. I am talking about ‘image noise’, the grainy-looking artefacts that become visible, especially in the shadow areas, when you push the ISO setting hard enough. Noise is always something unwanted, whether it comes through your ears or through the eyes. Noise in photography is described as a phenomenon which wasn’t part of the original scene when you took the shot. Image noise has always played a role in photography — just remember the days when we pushed our colour film to ISO 800. It boasted a 1.3-megapixel sensor, weighed in at 1.6kg and stood over 18cm tall — all for a cool US$17,950. Image 1 shows you this camera in action at ISO 1600. In those early days, Kodak referred to these sensitivity/ noise levels as ‘very aggressive’; others labelled them as ‘bogus’.
This was barely a generation ago, and we have come a long way when you think of the pictures you get out of your mobile phone. On the other hand, not much has happened in the professional full-frame (35mm) market over the last five years. Cameras sporting 30-plus megapixels are becoming more common, with Canon’s 5DS models leading the flock with 50-plus megapixels. However, note that the native ISO range has dropped back to 6400, compared with 25,600 for the 5D Mark III, which has half the pixel count and is more than four years old. Camera