through the 1980s and have called it ISO since then.

Use the lowest ISO that gives you the apertures and shutter speeds you need. Pump up the ISO up to get smaller apertures and faster shutter speeds. Unlike film, digital interchangeable-lens SLRs usually look great even at ISO 1,600. Don't be bashful: crank it up and it will look great.

For film or point-and-shoot digital cameras a normal ISO is 50 or 100. Faster ISOs are something like ISO 800 or 1,600. Digital SLRs are more sensitive to light than film or fixed- lens digital cameras, so their slowest ISO is often ISO 200.

The reason you want the slowest ISO is for lack of noise or graininess. The faster settings often are more grainy than the slower ones.

Summary

That's it. I have no idea why people make this so complicated. It has very little to do with photography. If you want to spend more time on this any book on basic photography covers it. I prefer the Ansel Adams' book "The Camera" here.

© 2007 KenRockwell.com

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