Canon PowerShot A640

Manual Control Options
Like many of its A-series siblings, the Canon PowerShot A640 offers a nice range of automatic to manual control. Users can graduate from the scene modes to the program and priority modes, to the fully manual mode. The shutter speed and aperture are changed using the multi-selector and the exposure compensation button. This isn’t the fastest or easiest way of doing things, but there just isn’t room for jog dials galore on the A640’s body. Still, the amount of manual control offered is great for the price of this digital camera.

Focus
Auto Focus (7.75)
The Canon PowerShot A640 has a 9-point through-the-lens auto focus system that has three modes: AiAF (default), FlexiZone, and Center. The AiAF system lights up green boxes around various areas of the frame to show where the camera is focused. The Center option is fixed to the middle, of course. The FlexiZone AF mode is very interesting. It allows users to manually move the focus point all around the frame with the multi-selector. The auto focus system works quickly and effectively, something that can’t be said of all compact digital cameras. It does focus much better and faster at the widest focal length over the telephoto end. The A640 normally focuses from 1.5 ft to infinity, but it has a macro mode that shortens that range. The macro mode is accessible from the bottom of the multi-selector and can focus as close as 0.39 inches in wide and 9.8 inches in telephoto. The A640’d auto focus system performed decently in low light, although it did take more time. The camera is equipped with a small, orange auto focus assist lamp to illuminate subjects that are dimly lit.

Manual Focus (2.5)
The bottom of the multi-selector accesses the manual focus mode in addition to the macro mode. Users can scroll right and left with the multi-selector to change the focus; as they do so, a scale shows up with distances on it. In the recording menu, users can choose whether to activate a zooming function in the manual focus mode. It enlarges the center of the image so it’s easier to see. This function isn’t complimented by the LCD screen’s resolution though. With only 115,000 pixels on the 2.5-inch screen, it is hard to focus on detailed subjects.

ISO (7.0)
Newer PowerShots are equipped with a Digic III processor that allows for even greater sensitivity, but the A640 still has a decent range from 80-800. This model also has automatic and High ISO Auto settings; the latter is for low light photography. All of the options are located in the Func./Set menu with a live view when scrolled through. This is a nice setup, and it helps users choose the best setting for the exposure.