ISO

What is the ISO setting for and how do you use it?

ISO determines how sensitive the image sensor is to light. If you set an incorrect ISO for any given light, you could find the resulting image looking either too light or too dark. If you find the time between pressing the shutter button and the camera actually taking the photo is too slow, then this is normally due to having an incorrect ISO setting. The challenge, is to choose the lowest ISO possible, that still allows you to use the shutter speed and aperture that you need.

The most common ISO speed settings are: 100, 200, 400 and 800. Depending on your digital camera model you may also have them in the range of 64, 100, 160, 200, 400, 640, 800, 1600 and other.

Good starting points for numerous situations

ISO 100-200: Perfect setting for when there is plenty of light, for example outside in sunny conditions.

ISO 400-800: Great for when the sky is overcast or in the evening time. Also good for indoor photography, day or night.

ISO above 800: Useful for darker situations, for example outdoor night scene or party, or walking around the city at night time.

We don’t normally recommend going above 800 for those who own entry level DSLR cameras, because they can result in very grainy looking images. Although technology is getting better. If you own a medium to high-end DSLR then you should be able to set the ISO to 1600 with no problems.

To help you gain a good understanding of how ISO works, we recommend setting your camera to Program mode, usually marked by a P on your top dial (check camera guide if you can’t find it). This will allow you to choose the ISO manually, while the camera chooses all other settings for you. Shoot in all different situations, for example daylight, indoors, night time, changing the ISO setting to suit the available light.

Truth be known, most professional photographers use Program mode while walking around, so they are ready for a quick snap when an unexpected opportunity arises!

Note: You cannot choose ISO speed when your digital camera is in automatic mode, it is chosen for you to suit the level of light available at that particular time.

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