A high-resolution sensor and high-end feature set mark the A640 out as ‘a little bit special’...
How does Canon’s A640 shape up against the high-end G7, both 10MP PowerShot models released simultaneously?
The A640 not only matches the PowerShot G7 in terms of its pixel count, but it houses a lot of similar features, too, ranging from the comprehensive exposure and metering modes, through to the AF system. However, three key features differentiate the two PowerShot models. For a start, the A640’s 4x optical zoom doesn’t have the same reach and it lacks image stabilisation. Also, the sensitivity range only extends to ISO 800, which is probably due to the A640’s use of Canon’s DIGIC II processor, as opposed to the DIGIC III engine in the G7.
With its satin-graphite finish and angular finger grip the A640 is certainly a nice camera to hold, with a DSLR-style dial giving ready access to the exposure modes. Key functions are a button push away in the ‘func’ menu with a generous 2.5in Vari-angle LCD enabling shooting from high and low angles. Alternatively, you can tuck the screen away and use the optical viewfinder to save battery power.
The zoom action is a bit louder and a touch slower than the G7’s, but this is easy to live with, as is the lower-resolution LCD. It may only have half the pixels of the G7, but images are still as clear and sharp on playback as you’d need.
It could well be that the A640 and G7 share the same sensor, but the results are very different. The A640’s images are noticeably coarser than the G7’s, with distinct RGB speckles at higher ISO settings. Sharpness is better, however – a result of the Digic II processor’s less-aggressive noise reduction, maybe? Fringing is a bit more noticeable, though. As with the G7, exposures and white balance are ultra reliable.
Value For Money
Think of the A640 as the ‘poor man’s’ G7 and you won’t go far wrong, as it offers many of the higher-end model’s features at a significantly lower price.
The A640 delivers a generally comparable feature set to the G7 and, while its images are noisier, they also appear sharper. I didn't expect to say this, but the A640 is the nicer camera of the two.