Noise to most of us is that loud bang as the door slams, the music thumping on the stereo, or kids yelling and screaming as they play in the back yard. However, when it comes to noise in relation to cameras, it has a whole different meaning. Noise involves those little colour speckles that appear on a digital image after you have taken a shot. Noise generally appears on compact – or point-and-shoot – cameras, as opposed to the more higher-specified DSLR camera.
Similar to a digital music file that will not degenerate, you would expect the same for a digital image. However, the issue with a digital image is that it is created from a non-digital source – the CMOS image sensor. To put it in simple terms, the sensor converts analogue signals into digital pixels. Somewhere in the process Noise is created and therefore the colour speckles appear.
So how do you get rid of Noise? There is no definitive answer, but here are a few ideas to consider when buying a new camera:
- Noise reduction software is available for some cameras, which will help reduce the number of specks.
- Avoid longer exposures – the longer the exposure, the more noise you will get.
- Using a high ISO (i.e., wanting to capture action shots in low-light conditions) will cause more noise.
- When buying a new camera and you want to reduce noise, choose one with a bigger image sensor relative to the number of megapixels it uses. For example, you might be looking to purchase one of two cameras, both with 10 megapixels. However, the key is the image sensor they both have. The one with the bigger sensor will have less noise.
- Talk it over with the sales assistant. Most sales assistants are camera buffs themselves, so query them about a device and how it handles noise.
Getting that perfect shot will always be the bug bear of the photographer – whether diehard professional or enthusiastic amateur. Noise is just one issue to contend with. Over the coming weeks we’ll go over some of the other issues that arise and give same handy hints on how to enhance your photographic experience.
* Tip: try to find an available light source and work with the light. This could be window light, street lights, reflections, candles, or the more obvious, a flash on or off the camera.