|The Canon PowerShot A640 has some very individual characteristics. In the first place, the PowerShot A-series of cameras is aimed at the broadest group of consumers; amateurs. They are just cameras for in and outdoors for taking family snapshots. Cameras like this are nearly always launched with 100% automatic features, with practically all manual exposure settings turned off and with everything being assessed by the camera, but not the Canon A640 and the rest of the PowerShot A family. This camera has many settings and functions that can be used by both beginners and more experienced photographers. The green button leaves everything to the camera, but if you want to get more out of it you will soon turn to the aperture and shutter speed. The Canon PowerShot A640 has a shutter speed series of 15 to 1/2500 seconds, depending on the means of recording and an adjustable aperture of f/2.8 in wide-angle and f/4.1 in tele. |
|Canon PowerShot A640 - Adjustments
A 4x optical zoom lens is a great range for an entry-level digital camera. The range gives enough possibilities to be able to capture everyday moments, and if you eventually need more range in wide-angle or tele you can expand the Canon PowerShot A640 with a converter. In combination with the 4x digital zoom you can then reach 16x zoom, but this will entail some loss of quality. The Canon A640's lens has a little distortion in both the wide-angle and tele settings. The distortion is almost negligible and will hardly be noticed. It is some loss of sharpness around the edges in wide-angle shots, but again, this is scarcely visible. The details are rich and the macro shots (possible from 1 cm) in particular give splendid results. A high resolution like ten Megapixels will often increase any chromatic aberration, but this is not the case with the PowerShot A640. The test pictures showed hardly any traces of the infamous purple edges around subjects where there was high contrast.
Canon colour reproduction
We were also happy with the colour reproduction. Although the colours are a bit cool, they were not very different to the situations being photographed. Taste is personal and some people will prefer warmer tones. A bit of over exposure via exposure compensation gives excellent exposure. As well as the automatic white balance and Custom, the Canon PowerShot A640 has other settings which will allow to master practically every lighting situation. It is handy that the camera remembers settings whenever they are switched on and off. The automatic white balance gives great results in normal outdoor conditions. Artificial light in indoor shots poses the most difficulties for the Canon A640. Manual exposure provides a good solution to overcome this problem.
Canon PowerShot A640 - Compact camera
10 Meg pixels in a compact camera would have been inconceivable a few years ago. This sort of resolution requires a lot of power from a camera, the files are much bigger that those of that generation of cameras. You don't notice any loss of performance with the Canon A640. The starting up speed and shutter delay are fast, but continuous shots are processed at a speed of approximately 2 fps. One small exception is the lowest compression at 10 Megapixels; it is not possible to record flowing continuous pictures in this setting. You must take the reading and writing speeds of the memory card into account. There are faster digital compact cameras on the market, but the Canon PowerShot A640 performs perfectly well and will be able to capture everyday moments without any difficulty. If you want to take action shots, though, you may have to look elsewhere.
|Canon DIGIC II processor
The Canon PowerShot A640 camera has a DIGIC II processor. This type of processor has more than proved its qualities and has brought many a Canon camera to a high performance level. The processor must also help to suppress noise and this works well up to 400 ISO. Above this, the noise ratio is so dominant that it is sometimes annoyingly visible. There is however, one good thing about the high ISO values: the details are preserved. The noise suppression is not so strong, and this may give more noise, but it also allows more detail to be shown. This is a feature that we have been seeing more of. In any case, it produces files that you can use third party noise suppression software on. Canon already has the new DIGIC III processor. Expectations of this new processor (which has been integrated into the PowerShot G7) are running high.
Canon PowerShot A640 - ISO settings
The pictures that we took with the Canon PowerShot A640 were really sharp. They have a lot of detail and can be easily post processed. The noise reduction does not leave heavy traces behind, which makes it possible to edit the images, something that comes in particularly handy with high ISO pictures. The prints of the test samples were of a really excellent quality. High ISO images up to 400 ISO can be printed easily at A4 format, but larger formats give visible noise. However, even 800 ISO samples produce good prints at postcard format.
Canon PowerShot A-series
The Canon PowerShot A640 digital compact camera has a host of talents. For years now, all the cameras throughout the entire PowerShot A-series have had the reputation of providing value for money and the Canon A640 is following in this tradition. Its versatility in combination with the all-round features and excellent optical zoom lens gives users a solid basis on which to practise photography up to a high level. Maybe some users will eventually want more and the Canon A640 can become a stepping stone on the way to a SLR.