10Megapixel A640 leads out Canon's new PowerShot range

The news

Canon is revamping its PowerShot range of compact digital still cameras and adding a new leader - the A640 - with a 10 Megapixel image sensor, a 4x optical zoom and a 2.5in LCD. This black-finished model is due in September at a suggested price of £329 (inc VAT) and will be arriving with two silver-finished companions, the A630 and A710 IS.

Although the A640 has 3Megapixels' more resolution than its forerunner, the A620, and that does allow for printing of pretty large images - as shown by the shot below taken at Canon's launch event - the real benefit for most users will be the ability to crop into an image and still be able to print it at A4 - the largest size that most home printers max out at.

The 8 Megapixel A630 (£269) replaces the 5 Megapixel A610 and is in effect, a lower-res version of the A640. In contast, the 7.1 Megapixel A710 IS (£289) - a replacement for 6 Megapixel A700 - has a longer optical zoom, 6x, and offers a feature that neither of the other newcomers provides, an optical image stabiliser.

Daniel Benjamin holding print from PowerShot A640

Daniel Benjamin, Canon product manager digital
cameras, holding a big enlargement of an image said
to have been taken on a 10 Megapixel PowerShot A640
(Click for larger image - likewise images below)

PowerShot A640

Among the top shared features of the three newcomers are:

* A 2.5in LCD screen (movable with the A640/A630; fixed with the A710) and an optical viewfinder
* Canon's own DIGIC II image processor - as used in its latest digital SLRs and said to provide great images, fast start-up and longer battery life
* Intelligent Scene Analysis based on Photographic Space (iSAPS) - said to optimise key camera settings before every shot
* Nine-point Artificial Intelligence Auto Focus(AiAF) - for accurate focussing when the subject is not in the centre of the screen
* FlexiZone AF/AE - allowing the user to choose which part of the image to focus on
* 35mm equivalent focal lengths - 35-210mm (A710 IS) and 35-140mm focal length (A630/A640)
* Maximum ISO rating - ISO 800
* High ISO Auto setting - said to prioritises fast shutter speeds and cut down blurring by by automatically using the higher ISO sensitivities
* Memory card support for the SDHC standard - with storage capacities of 4GB or more
* Multiple shooting modes (20 for the A710; 21 for the others)
* Digital Tele-Converter and Safety Zoom

The Digital Tele-Converter feature is described as being like placing an accessory lens on the front of the camera, and adding a constant zoom to every shot. There are two digital zoom ratios for each camera - 1.4x and 2.3x for the A640; 1.6x/2.0x for the A630; and 1.5x/1.9x for the A710 IS.

But, Canon says, while optical converter lenses cause a reduction in aperture and thus require a slower shutter speed, the Digital Tele-Converter maintains aperture size, reducing the risk of image blur.

That much is probably true of all digital zooms but the accompanying Safety Zoom feature is reckoned to protect the image from unwanted interpolation at high levels of digital zoom, and to let users extend zoom magnification without sacrificing image quality.

Rather than leave the user to figure out where interpolation artefacts might adversely affect shots, the zoom level is automatically restricted according to the size at which the user decides the image is likely to be printed.

So, for images that will be printed large, the system prevents the use of the digital zoom, while for those that will be printed small, it allows the maximum - 24x in the case of the A710 and 16x for the other two - with varying zoom levels in between according to the expected print size.

PowerShot A710 IS

Powershot A630

Among the list of accessories for the three new PowerShots are screw-on wide (0.7x) and tele (1.75x) converter lenses and an underwater housing said to be safe to use to a depth of 40metres. This has an SRP of £150 but anti-buoyancy weights are separate and cost extra.

A710 IS with teleconverter

PowerShot underwater housing (SP-DC6)

Check out the specs of each model (PDFs: A640, A630, A740) and the press releases, A640 and A630 (on page two) and A740 IS (page three), then share your thoughts about these models in this thread in the HEXUS.lifestyle.news forum.