Disadvantage of Higher ISO?

[PRC 20D]

Hey People,

I have read that there is a disadvantage of shooting at a higher ISO, but the stupid things never tell me what it is. Can anyone help me?

[tiggstales]

Higher ISO's will produce more noise. The amount of noise will vary from camera to camera. With my 20D, the noise really starts to become noticeable at ISO800. Many point & shoot camera will start to show noise at any ISO higher than 100.

[PRC 20D]

I know i am going to come across as an idiot here, but I never understood what noise was. Care to help me out?

[photosbyVP]

Noise is pretty much digital Grain..

it's a bit like when you're watching a video tape on tv...and the tape ends...showing the "ants"..just a lot less severe..and smaller 'ants'

it's grain though..
Vito

[tiggstales]

As Vito said, noise gives an image a grainy look . Here is an example, although it's not as noticeable at this small size. I accidentally shot this at ISO1600...see the grain, especially in the background. It can also appear as tiny colored dots.

[PRC 20D]

Ok, cool. I used to shoot outdoors at ISO 1600, so if I go down to 400 or less, I should have better "quality" pics right?

[Paul_OH]

A LOT better! The lower the iso the better the pic, you should only really raise the iso in order to keep a decent shutter speed or unless you want some artistic effect.

Paul