ISO – Digital Camera Settings

…or, ISO Need a Faster Shutter Speed

Camera ISO settings

Setting your camera's ISO

Relationship between ISO and Shutter Speed

At any given aperture you can raise your shutter speed by increasing your digital camera’s ISO setting. Doubling your ISO number doubles the speed of your shutter.

Why would you want to do this?

This is handy when you are in low light conditions and want to capture sharp images but you don’t have a tripod, or you are already at your widest aperture (at a set ISO) and want an even faster shutter speed to ‘freeze’ fast moving subjects. High ISO settings also enable you to capture images in low light conditions, such as concerts, where the subjects are beyond the range of your flash.

ISO Settings

You’ll find your ISO setting in your camera’s menu and/or as a dial on your camera body. There is also an Auto ISO setting which makes your camera flex its ISO settings according to the lighting conditions and aperture combination. Some Auto ISO settings have a limit of 400 or 800 ISO and these are often not high enough for low-light photography, so you’ll need to set your ISO manually.

ISO settings and Image Quality

Beware: There is a downside to raising your camera’s ISO – a reduction in image quality. Images at higher ISO settings contain more ‘grain’. The higher the ISO, the grainier the image. (The issue is less apparent when using new pro and semi-pro cameras, where ISO settings can be increased substantially with marginal loss of quality, but it still occurs).

Your lowest ISO setting produces the highest quality image.

Your ISO Settings Stay Set

Remember: Your camera’s ISO setting stays set, even when you switch off your camera. It’s good practice to reset your camera’s ISO to it’s minimum when you finish taking photographs.This makes sure that you have the highest quality settings for your next shoot, or trip.