Things I Have Learned from Photography #12

12.     You need to memorize the standard ISO settings.

Here are the standard ISO settings:

100 200 400 800 1600 3200 6400

If you move up one setting (one stop) you double the light of the exposure. If you move down one setting (one stop) you halve the light of the exposure.

The higher the ISO, the more the data recorded by the camera sensor is amplified. If it is a really bright day, I use ISO 200. If it is a really cloudy day, I need more light in the camera so I use ISO 400 or ISO 800. If I am shooting inside and need a lot of extra light, I shoot ISO 1600 or ISO 3200.

It is not hard to memorize the ISO standard stops, because there is a pattern. You double the ISO setting and you double the light in the exposure.

Some cameras, like my Olympus, do not have ISO 100. The lowest ISO is 200.

There are other ISO choices. If you look at the dial or menu where you change ISO on your camera you will see:

100 125 160 200 250 320 400 500 640 800 1000 1200 1600 2000 2500 3200

One turn of the dial changes the stop by 1/3. That makes the image about 66% brighter. It takes three turns to get a full stop where the light is doubled. It does not really matter where you start. For example if you are shooting at ISO 320 and want to double the exposure, you turn the ISO dial three times and your get to ISO 640. It is the same pattern of doubling, by the way.

Even if you are a little unsure about stops of light, memorize the ISO standard settings. It is the first step in understanding the exposure triangle.