Help with ISO

Stephen P

I'm finding it hard to grasp how ISO works on digital cameras. Could someone explain to me in "laymans" terms how it works and in what settings you should use a particular ISO setting?

Thanks in advance!

Stephen

Basically, the higher the ISO, the more sensitive it makes the sensor in your camera, but this also makes it prone to noise, which is comparable to grain in high speed film.
You'd normally want to keep the ISO as low as possible for the best image quality - i.e. there's no sense in shooting in ISO 800 in bright daylight, as 100 will be fine. When you're in a low light situation where you won't have the use of a tripod or whatever, increasing the ISO may be necessary to get a clear shot, but there will be noise introduced. Some sensors are better than others for high-ISO performance. Most cameras perform some kind of in-camera noise reduction process too, which can often make your low-light pictures look muddy and crappy.

Stephen P

Stephen wrote:

Basically, the higher the ISO, the more sensitive it makes the sensor in your camera, but this also makes it prone to noise, which is comparable to grain in high speed film.
You'd normally want to keep the ISO as low as possible for the best image quality - i.e. there's no sense in shooting in ISO 800 in bright daylight, as 100 will be fine. When you're in a low light situation where you won't have the use of a tripod or whatever, increasing the ISO may be necessary to get a clear shot, but there will be noise introduced. Some sensors are better than others for high-ISO performance. Most cameras perform some kind of in-camera noise reduction process too, which can often make your low-light pictures look muddy and crappy.

Thanks Stephen for that info. It makes more sense now.

Oriel

Raising the ISO value increases the amount of power being fed to the camera's sensor.

Zillah

Never be afraid to increase ISO in darker conditions. A whole load of grain/noise will disrupt a photo far less than even the tiniest bit of camera shake/motion blur, which would result from having to use a longer shutter speed.