The Canon PowerShot A640 couples a 10 megapixel CCD imager sensor with a 4x optical zoom lens that offers a 35mm-equivalent focal range of 35 to 140mm. That's a moderate wide-angle that reaches to a somewhat more generous telephoto than you'll find on most compact cameras. Maximum apertures vary from f/2.8 to f/4.1 across the zoom range. The A640's sensor yields an ISO range of 80 to 800, with shutter speeds of 1/2,500 to 15 seconds.



Link: Imaging Resource