Canon EOS Rebel T3i 18-135mm IS Lens Kit EOS REBEL T3i / EOS 600D Instruction - Page 79

Z: Changing the ISO SpeedN Set the ISO speed (image sensor's sensitivity to light) to suit the ambient light level. In Basic Zone modes, the ISO speed is set automatically (p.80). 1 Press the button. (9) X [ISO speed] will appear. 2 Set the ISO speed. Press the key or turn the dial to select the desired ISO speed, then press . You can also set the ISO speed in the viewfinder while turning the dial. With [AUTO] selected, the ISO speed will be set automatically (p.80). ISO Speed Guide ISO Speed Shooting Situation (No flash) Flash Range 100 - 400 400 - 1600 1600 - 6400, H Sunny outdoors Overcast skies or evening time Dark indoors or night The higher the ISO speed, the farther the flash range will extend (p.90). * High ISO speeds will result in grainier images. Under [7 Custom Functions (C.Fn)], if [2: ISO expansion] is set to [1: On], "H" (equivalent to ISO 12800) can also be set (p.252). Under [7 Custom Functions (C.Fn)], if [6: Highlight tone priority] is set to [1: Enable], ISO 100 and "H" (equivalent to ISO 12800) cannot be selected (p.254). Shooting in high temperatures may result in images that look grainier. Long exposures can also cause irregular colors in the image. When you shoot at high ISO speeds, noise (banding, dots of light, etc.) may become noticeable. 79