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.

Though the Canon A640 has a relatively large 2.5 inch LCD, Canon retained a real image optical viewfinder in the A640’s design.

Not only can optical viewfinders save battery life if you turn off the LCD display, but they’re also useful when ambient light makes it tough to see many LCDs properly. Power comes from four AA batteries, and Canon includes single-use alkaline disposables in the product bundle.

Also included with the Canon A640 is a 32MB MultiMediaCard — perhaps slightly larger than average, but still not sufficient for more than a handful of photos at the highest resolution and lowest compression. If you don’t already have some, you’ll want to purchase some rechargeable batteries and a larger flash card along with the camera.

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