Yup, basically light sensitivity, lower ISO, less sensitive to light, smoother image. Higher ISO, more sensitive to light, faster shutter speed but noisier, image looks grainy. HTH, basics to ISO
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Canon 40D (350D backup) - EF-S 18-55 - EF-S 17-85 - EF 100-300 - EF 50 - Canon 430 EX || Speedlite - Canon BG-E2N Grip
Adobe Photoshop CS4 Extended
AX-10 Crawler - Thats all I have left!!!