Compact

Canon's new PowerShot G7 has much to recommend it over earlier G-series models, with a redesigned body that's slimmer and 60 grams lighter than its predecessor and has classic rangefinder-like styling. Sensor resolution is now 10-megapixels and the vari-angle LCD is replaced by a fixed 2.5-inch monitor. The optical zoom range increases from 4x to 6x and image stabilisation is added. On the downside, raw format support has been dropped, the G7 is limited to the sRGB colour space and you can see the lens through the viewfinder when it's at its widest setting.

Image stabilisation is achieved by shifting part of the lens to counteract camera movement. Three image stabilisation modes are offered: continuous, shoot only and panning, the latter two being unavailable in movie mode. Continuous is easier to use but consumes more power, while shoot only is slightly more effective. The panning option only counteracts vertical movement, allowing photographers to track subjects that move horizontally.

A special SR (Small Radius) coating is used on lens elements where the rear surface is significantly smaller than the front surface. Canon claims it maintains high-resolution and colour fidelity by dramatically reducing ghosting and flare. It also minimises chromatic aberration.

Controls
The abundance of controls will please gadget freaks. Two dials adorn the top panel, one covering ISO sensitivities, which range from 80 to 1600 and include a Hi setting for ISO 3200. The other covers shooting modes and includes the Auto, P, Av, Tv and M settings plus Scene, Stitch Assist and Movie modes. Two Custom memory banks allow users to store frequently-used camera settings for quick recall. Zooming is accomplished via a ring surrounding the shutter button. The on/off button lies just behind. The top panel also carries a flash hot shoe, which is raised slightly, while a strap eyelet is inserted in the right side edge.

Most of the rear panel is covered by the LCD, beside which lies an arrow pad/control wheel for setting camera functions. This wheel can be used to set Av and Tv values using new bar graphs displayed on the monitor. (The Av and Tv bars are displayed together during Program Shift so users can see the combination they have set.) In M mode, an Exposure Level Indicator on the right side of the LCD lets users monitor exposures.
In the centre of the arrow pad is the Func./Set button, which accesses eight banks of settings, covering white balance, the My Colours menu (see below), bracketing, flash output adjustments, metering patterns, a 3x neutral density filter and image size and quality. The white balance, My Colours, ND filter and size/quality (frame rate) settings operate in both the stills and video modes but the optical zoom and focus are locked with the first frame recorded.

Six additional buttons occupy the rear panel, covering shortcut/print, playback, AE/FE lock/microphone, delete/AF zone selector, exposure compensation/jump, display and menu. The arrow pad also accesses manual focus, flash, drive/self-timer modes and Macro settings.

Canon provides plenty of pre-sets to make shooting easy, with seven white balance settings (plus manual measurement), 16 Special Scene modes and at least as many picture effects as other Canon digicams. New additions to the Scene mode menu are the Aquarium and ISO 3200 modes. These settings are accessed by selecting the Scene mode in the shooting mode dial then rotating the control dial wheel. An icon and the setting name are displayed with each more - but no other information.

The My Colours menu is a new addition to the G-series. It's accessed via the Func./Set button and lets users choose from Vivid, Neutral, Sepia, Black & White, Positive Film, Lighter Skin Tone, Darker Skin Tone, Vivid Blue, Vivid Green, Vivid Red, and Custom Colour modes - as well as an Off setting. Photographers can add these effects before or after recording the image or movie. Contrast, Sharpness, Saturation, Red, Green, Blue, and Skin Tones can each be adjusted in five levels.

Features
An important component in the G7 is the latest DiG!C III image processor, which supports new face detection and noise reduction technology. The former can identify up to nine faces in a frame and adjusting camera settings accordingly. Selecting the Face Detect mode in the AF menu brings DiG!C III analysis into play. When faces are detected, up to three AF frames will be displayed on the LCD, with up to nine frames being used for actual focusing. If no faces are detected, the AF system reverts to standard 9-point AiAF focusing. Face Priority auto-exposure is linked to the Face Detect setting. Depending on lighting conditions it will expose the shot - or add flash fill - to record skin tones correctly.

Noise reduction processing is applied automatically at high ISO settings and appears to cut in at ISO 800. Test shots taken at this setting showed less noise than we're accustomed to from the majority of cameras. By ISO 1600, however, the noise-reduction processing produced a significant loss in resolution and test shots appeared both soft and grainy, especially for long exposure times.

Digital zoom magnification of up to four times is available and the G7 includes pre-sets of 1.4x and 2.3x for fast access. Shots must be framed using the LCD and you can't take widescreen pictures. Nor can you use the HI ISO setting and the Colour Accent and Colour Swap effects are inaccessible.

G7 photographers can record up to 4 GB of movie clips at Standard (VGA/QVGA) or High (1024 x 768 pixels) resolution or up to three minutes per clip in Compact (160 x 120 pixels) mode. The Colour Accent and Colour Swap effects can be used with Standard movies, which can be captured at 30 or 15 fps, whereas the High and Compact movie settings record at 15 fps. Optical image stabilisation works with all modes and the digital zoom can also be used. So can manual focusing.

The G7 uses the same NB-2LH rechargeable lithium-ion battery as the EOS 400D. Canon claims a full charge will provide power for approximately 220 shots with the LCD on or 500 shots with it off. Approximately five hours of playback is supported.

Playback
Image playback facilities are pretty standard, although reasonably extensive. Pressing the playback button displays the last shot taken and sets the camera into playback mode. Up to 10x image magnification is available through the zoom lever and you can scroll around the image using the arrow pad. Shots can be displayed individually or in nine-frame index pages and vertical images viewed individually can be automatically rotated to display right way up.

The My Category function lets you organise images into pre-set categories, such as People, Scenery, Events, etc. You can use the Jump function to view images in particular categories or select images by shot date or folder number. The Jump function can also be used to scroll through images in jumps of 10 or 100 shots. Three display options are supported in playback mode: the image alone, image plus basic data or thumbnail plus histogram and full shooting data. In-camera editing support allows users to crop, rotate and tag image files and slideshow playback is also supported.

Performance
Shots taken with the test camera looked sharp, colour-accurate and correctly exposed, although with a slight bias towards recording shadow detail, which led to loss of highlights in bright, contrasty conditions. In overcast lighting, test shots recorded a full dynamic range and produced very pleasing results. We were particularly impressed with the G7's performance with backlit subjects in overcast conditions (a sample shot is shown below).

Imatest testing showed the G7 to be capable of producing high (although not outstanding) resolution at middle apertures and focal length and low ISO settings. However, resolution declined progressively from ISO 400, with very low figures at ISO 1600. Colour accuracy was above average and chromatic aberration was low enough to be negligible. Some slight colour shifts were detected in cyan and yellow hues and the test camera produced a small degree of over-saturation in blues and reds. Edge-to-edge sharpness was good in shots taken at low ISO settings and we found no evidence of coloured fringing in outdoor shots.

Digital zoom shots were clean and relatively artefact-free and close-ups contained plenty of detail. Selective focusing was relatively easy in Macro mode but the relatively small size of the sensor made it more difficult to blur background detail with normal subject distances - even when a large aperture was set. White balance performance was excellent, except when the auto setting was used with incandescent light, where the resulting orange was not eliminated. However, the manual pre-set and custom measurement modes eliminated the orange cast.

Flash performance was competent. Although red-eyes appeared in the auto flash mode, they were easily eliminated in editing software and, therefore, only a minor problem. The ability to adjust flash output was a big plus for portrait shots and also in areas where additional light was needed.

We measured an average start-up time of 1.5 seconds and capture lag of 0.5 seconds, which reduced to 0.1 seconds with pre-focusing. Shot-to-shot times averaged 1.8 seconds. The burst mode recorded six shots at 0.5 second intervals before slowing down a little. It took approximately four seconds to process a burst of 10 shots.

IMATEST GRAPHS

SAMPLE IMAGES
Most of the images below were taken at a local festival parade. They show the versatility of the G7 for candid and street photography.

Full 6x optical zoom extension.

Maximum wide angle setting.

Impressive performance with backlit subjects.

Excellent detail in close-ups.

Image sensor: 7.18 x 5.32 mm Primary Colour CCD with 10.4 million photosites (10.0 megapixels effective)
Lens:  7.4-44.4mm f2.8-4/8 zoom lens (35-210mm in 35mm format)
Zoom ratio: 6x optical, up to 4x digital
Image formats: Stills – JPEG (Exif 2.2); Movies – AVI Motion JPEG/WAV (XGA, VGA, QVGA, QQVGA
Image Sizes: 3648 x 2736, 2816 x 2112, 2272 x 1704, 1600 x 1200, 640 x 480
Shutter speed range: 15-1/2,500 sec.
Exposure Compensation: +/- 2.0 EV in 1/3-stop increments
Focus system/range: TTL Autofocus (Manual focus available) with Face Detect/9-point AiAF/1-point AF; range 50cm to infinity; macro – 1-50 cm, Manual – 1 cm to infinity
Exposure metering/control: Evaluative, Centre-weighted average, Spot metering (fixed central or linked to AF point); P, A, S, M, Custom (x2), Special Scene (16 settings), Stitch Assist, Movie
White balance: Auto, Daylight, Cloudy, Tungsten, Fluorescent, Fluorescent H, Flash, Underwater, Custom
Flash modes/range (ISO auto): Auto / flash On / flash Off, (Red-eye reduction On/Off) Slow-synchro; range 50cm - 4.0m (W), 50cm - 2.5m (T); Hot shoe support
ISO range: Auto, Hi ISO Auto, ISO 80, 100, 200, 400, 800, 1600 (equivalent)
Sequence shooting: High-speed – approx 2.0 fps; Normal – approx 0.8 fps
Storage Media: SD, MMC or SDHC cards (32MB MMC supplied)
Viewfinder: Real-image optical zoom
LCD monitor: 2.5 inch low-temperature polycrystalline silicon TFT colour LCD (with wide angle viewing) 207, 000 pixels
Power supply: NB-2LH rechargeable lithium-ion battery
Dimensions (wxhxd): 106.4 x 71.9x 42.5 mm
Weight: Approx. 320g (without battery and card)