Compact

Canon's PowerShot A580 is the middle model in a trio of similar digicams that are targeted at family snapshooters. Affordably priced, their RRPs go up in $50 steps, corresponding with increasing resolution, zoom range and associated functions. All three models have 2.5-inch LCDs and are powered by two AA batteries. The two top models have 8-megapixel resolution and 4x optical zoom lenses, while the A470 combines 7.1 megapixels with 3.4x optical zoom. The top-end A590IS model is the only one with image stabilisation.

Overall build quality for the A580 was average for a plastic camera. The body and lens appeared to be well integrated but we found the battery/card compartment awkward to open and close, though the cover fitted securely. No tether is provided for preventing batteries from falling out when the cover is open, although the SD card locks in firmly and is simple to remove.

Front and rear views of the PowerShot A580.

Face detection technology is included in all three models and covers auto focusing, exposure, flash exposure and white balance. It's a first at this level and an attractive feature for the target market. When the Face Detect is selected in the AF Frame setting in the camera's menu, the camera will automatically search for faces in the scene. A green square identifies all faces detected on the LCD. If no face is detected, the camera defaults to AiAF mode.

A new AF Point Zoom function, which is only available in Face Detect mode, lets you enlarge the AF frame when the shutter button is half-way pressed to check that the subject's eyes are open. In auto mode, the AF system scans the subject and automatically sets the lens to focus, regardless of whether the camera is in normal or close-up mode. Pressing the 'macro' button on the arrow pad lets you choose between normal and close focusing, the latter covering subjects from 5 to 45 cm from the lens. AF performance in low light has also been improved by about a stop.

A new Face Select and Track function allows the AF system to track a moving subject within a certain distance range. Once the focus is fixed to a subject's face, the frame can be set to follow the subject so he or she remains in focus and is correctly exposed.

Selecting Red-Eye Correction in the flash menu enables the camera to automatically search for and correct red eyes in flash shots. You can also correct red eyes in playback mode. The PowerShot A580 and its entry-level sibling the A470 lack aperture and shutter priority modes. Instead, they have the same auto and camera manual modes as the Ixus models, although actual camera settings are accessed slightly differently. The rear panel has a slider switch for moving between shooting and playback modes.

The A580's grip, though small, was comfortable and most controls were within easy reach and straightforward to operate. Unlike many snapshooters' digicams, the A580 has an optical viewfinder which, though small, was usable when the LCD was difficult to view. On the top panel is a large mode dial with auto, manual and Easy mode settings plus pre-sets for portrait, landscape, night snapshot, kids & pets, and indoor modes.

In the Manual mode, a wide range of camera settings are adjustable.

The Auto mode only allows image size and quality to be changed.

The Easy mode is designed for novice users and people who don't want to change camera settings. The only adjustments available in this mode are the flash settings, which can be changed via the arrow pad button to be adjusted. The menu button is unusable in this mode so there's no way to adjust resolution and quality settings, which (fortunately) default to the top size and quality.

Swap to the Easy mode and the only function that can be changed is flash settings.

Typical image sizes are shown in the table below.

The Date Stamp setting lets users embed the date on shots as they are recorded. This allows them to be printed with a date overlaid on the shot. The image size is fixed at 1600 x 1200 pixels and the quality at Fine, which is appropriate for printing on 15 x 10 cm snapshot-sized paper. As the date stamp cannot be deleted from the image data this setting should only be used when a date imprint is required.

The SCN mode setting accesses pre-sets for night scene, sunset, foliage, snow, beach, fireworks and aquarium modes. The final setting is a movie mode, which lets users choose between standard and 'compact' movies.

The Scene mode only permits adjustments to exposure levels, image size and quality. Flash, ISO, drive and focus range settings are adjustable via the arrow pad, depending on which mode is selected.

Adjustments supported in the Movie mode.

Standard movie clips are recorded with sound in VGA resolution at 20 frames/second and standard play and long play (LP) settings are provided. Alternatively, you can shoot QVGA (320 x 240 pixels) clips at 30 frames/second. Compact movies are recorded at 160 x 120 pixel resolution with a frame rate of 15 fps and are suitable for emailing or posting on websites. Typical recording times for the four settings are provided in the table below.

During video recording, an indicator dot plus Rec. is displayed on the LCD and the elapsed time counts up in the lower right corner of the monitor. Recorded slips are displayed by setting the mode switch to playback, selecting the clip and pressing the Func/Set button. You can skip to the next clip, fast forward or backward through a clip or pause and restart playback. Sound volume is adjustable with the up/down buttons on the arrow pad.

Three playback settings are provided for still pictures: no data, basic file data and shooting data plus thumbnail and brightness histogram. The camera is supplied with the standard Canon Digital Camera Solution Disk, which contains applications for downloading, viewing and printing images as well as Canon's PhotoStitch panorama stitcher. A comprehensive software guide is supplied, along with a printed user manual for the camera. A 32MB SD card is also provided.

Performance
Pictures taken with the test camera showed a slightly wider dynamic range than we normally see with small-sensor digicams. Although we found blown-out highlights in outdoor shots, shadows were captured with minimal noise and a fair amount of detail. Colours were natural looking and saturation appeared to be at normal levels.

Imatest showed the A580 to be capable of high resolution for its sensor size and indicated a close correspondence between centre and edge resolution that showed edge softening to be minimal. Resolution had begun to decline by ISO 400 but only plunged at the ISO 1600 setting, where there was the greatest discrepancy between centre and edge resolution. The graph below shows our test results.

Lateral chromatic aberration was consistently low in our Imatest tests but we found traces of coloured fringing at the edges of shots when they were enlarged to 100% size.

Digital zoom shots were soft and artefact-affected. The flash required a sensitivity setting of ISO 200 before it could illuminate an average-sized room but produced even, well-balanced exposures throughout its range.

White balance performance was slightly better than average, with excellent colour reproduction under fluorescent light. However, the camera was unable to correct the orange hue of incandescent light. We measured a consistent capture lag of 0.5 seconds, which reduced to less than 0.1 seconds with pre-focusing. Shot-to-shot times averaged 3.2 seconds without flash and just under five seconds with.

The continuous shooting mode recorded Large/superfine JPEGs at 0.7 second intervals without slowing during a burst of 10 frames. It took 3.5 seconds to process this burst.

IMATEST GRAPHS

Centre-of-field resolution.

Edge resolution.

SAMPLE IMAGES

Auto white balance with incandescent lighting.

Auto white balance with fluorescent lighting.

Close-up.

Digital zoom

ISO 1600 at night.

Short exposure at ISO 80.

Short exposure at ISO 1600.

Image sensor: 5.76 x 4.29 mm CCD with 8.3 million photosites (8.0 megapixels effective)
Lens: 5.8-23.2mm f/2.6-5.5 zoom (35-140mm in 35mm format)
Zoom ratio: 4x optical, up to 4x digital
Image formats: Stills – JPEG (Exif 2.2); Movies – AVI; Sound – WAVE (monaural)
Image Sizes: Stills - 3264 x 2448, 3264 x 1832, 2592 x 1944, 2048 x 1536, 1600 x 1200, 640 x 480; Movies - 640 x 480 at 20 fps (SP/LP); 320 x 240 at 30 fps; 160 x 120 at 15 fps
Shutter speed range:  15–1/2000 sec.
Image Stabilisation: n.a.
Exposure Compensation: +/-2 stops in 1/3-stop increments
Focus system/range: TTL autofocus with Face Detect, AiAF (9-points) and Centre modes; range 45 cm to infinity; macro 5-45 cm
Exposure metering/control: Evaluative, Centre-weighted average or Spot metering; Auto, Easy, Manual shooting modes plus 12 scene mode settings
ISO range: Auto, ISO 80, 100, 200, 400, 800, 1600
White balance: Auto, Day Light, Cloudy, Tungsten, Fluorescent, Fluorescent H or Custom
Flash modes/range (ISO auto): Auto, on, off (facial brightness is evaluated in Face Detect AF); range 30 cm–3.5 m
Sequence shooting:  Approx. 1.4 shots/sec.
Storage Media: SD/SDHC cards
Viewfinder: Real-image zoom viewfinder
LCD monitor: 2.5-inch type, TFT colour LCD, approx. 115,000 dots
Power supply:  2 AA-size alkaline or NiMH batteries
Dimensions (wxhxd): 94.3 x 64.7 x 40.8 mm
Weight: Approx. 175 g (without batteries and card)