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Angled front view of the PowerShot G10 showing the retracting lens, viewfinder window and built-in flash.

Surrounding the base of the lens mount is a threaded ring, the LA-DC58K conversion lens adaptor, which is used for attaching the optional TC-DC58D 1.4x teleconverter lens. This accessory adds 140 grams to overall weight and 41.2mm to body thickness. The camera is supplied with a standard neck strap.

Although the new model retains the classic rangefinder styling of its predecessor, Canon has revamped the controls on the top panel to provide easier access to the ISO and exposure compensation settings. The ISO control dial on the G9 has been replaced in the G10 by an exposure compensation dial and the mode dial now sits atop a larger ISO control dial on the right side of the hot-shoe. Indicator LEDs light up on both dials when the camera is in use to show current settings. These changes should please traditionalists, particularly as the mode dial on the G10 carries the same settings as the G9.

Top panel view of the G10 showing the three adjustment dials and the LED indicators.

The rear panel control layouts of the two cameras are almost identical, although the buttons are slightly larger on the new model. However, the resolution of 3-inch LCD monitor on the G10 has been doubled to 461,000 pixels, compared with 230,000 pixels on the G9. The new display not only provides better colour, contrast and sharpness; it also gives more scope for magnifying shots in playback mode to check sharpness and shadow noise.

The rear panel, showing the LCD screen and main button controls.

The viewfinder on the G10 also claims to be slightly bigger and brighter than its predecessor. However, it's still pretty small and cramped and its hard surround can scratch the lenses of glasses. Interestingly, diopter adjustment is provided - a rarity in a compact digicam. Nevertheless, we still feel most users will compose the majority of their shots with the camera's excellent LCD screen.

Two main menus are still available. The more comprehensive suite of controls is accessed via the Menu button, while the Fn. Button provides quick access to resolution, quality, white balance, bracketing and My Colours settings and lets users adjust flash output levels and turn the neutral density filter on and off.

 
The first page of the shooting menu functions accessed via the Menu button

 
Function menu settings for JPEG shots in the P, Av, Tv or M modes.

The high sensor resolution has given Canon more scope for digital zoom settings with the addition of a Safety Zoom function that adjusts the zoom ratio according to the resolution setting. Safety Zoom zooms by cropping the image so if you've set the image size to Large, this function is not available, whereas setting the image size to Small provides up to 20x magnification.

Digital zoom combines cropping with interpolation. Three settings are provided on the G10: Standard, which provides 4x magnification on top of the 5x optical zoom, along with fixed ratios of 1.7x and 2.2x. All three settings result in surprisingly little loss of image quality for the magnification ratio.

A couple of G9 features have been dropped in the new model. For starters, there's no time-lapse mode and no support for widescreen HD video recording. Although the G9 only provided 1024 x 768 pixel video at 15 frames/second (which isn't widescreen), the G10 is stuck with the standard-definition VGA and QVGA option. (Although, in its defense, most buyers won't be purchasing this camera for its video capabilities.) 

Sensor & Image Processing
The 7.6 mm x 5.7 mm CCD image sensor in the G10 carries a total of 15 million photosites with 14.7 megapixels effective. By our calculations, each photosite has a surface area of 1.72 microns, which is 0.18 microns less than the G9's. Moving to larger image files has meant a slight decrease in burst shooting speeds, with the top speed in the G10 being 1.3 frames/ second, compared with 1.5 frames/second in the G9. The AF continuous shooting mode has the same 0.7 frames/ second speed in both cameras.

Internally, the biggest change in the new model is the shift from the DiG!C III image processor to the new DiG!C 4 chip, which includes support for the new Servo AF, Face Detect Self Timer and i-Contrast functions. i-Contrast provides a form of dynamic range adjustment similar to Nikon's D-Lighting but only offers two settings: auto and off. The Face Self-Timer mode in the Drive sub-menu is programmable to capture up to nine shots in sequence.

DiG!C 4 has also allowed the top shutter speed to be increased from 1/2500 second to 1/4000 second and improved camera response times.  These improvements were evident when shooting in brightly-lit conditions where autofocusing was as fast and accurate as we've seen in any digicam we've used this year.

Like its rivals (Nikon's Coolpix P6000 and Panasonic's DMC-LX3), the G10 supports both JPEG and raw file capture. If you wish to record raw and JPEG images simultaneously, this facility must be selected in the camera menu. However, you can't choose the image size or compression ratio for the JPEG shot; the default setting is Large/Fine.

Raw files are losslessly compressed while JPEG compression is relatively modest with the Superfine setting, but much heavier with the Fine and Normal modes. Typical image sizes are shown in the table below.

The G10 offers neither widescreen or High Definition video capture. However, users benefit from a new, more efficient video recording system, which uses the same H.264 video codec as Blu-ray disk and Digital TV signals.
H.264 is part of the MPEG-4 specification and sometimes referred to as 'MPEG-4 Part 10'. It provides higher video quality at a given bit rate, which minimises the incidence of artefacts, such as blockiness and colour banding. It also allows more video data to be stored in a given space. As in the PowerShot G9, audio data is recorded monaurally. Typical video recording times for a 2GB memory card are shown in the table below.

The G10 can also be used as a sound recorder and offers a maximum capacity of up to two hours at a time.

Handling
Being much smaller and less conspicuous than a DSLR, the G10 is a great little camera for candid and street photography. With the default settings, it is quiet enough not to be noticed and you can adjust the volume of the start-up and shutter sounds - or even turn them off completely - if you want completely noise-free operation.

Although you can operate the G10 with one hand when it's in the full auto or P mode or if you opt for one of the Scene pre-sets, if you wish to adjust camera settings it must be used with both hands. Even then, making some adjustments can be tricky. As in the G9 (and some other PowerShot and Ixus models), the arrow pad is surrounded by a control dial, which is used for selecting certain functions.

Some of the controls are pretty crowded and multi-functional and it takes a while to work out a usable sequence of button pressing. The control dial is designed to be adjusted with your thumb - and this means changing its position. In addition, the thumb is used for the metering button, which allows you to swap between the aperture and shutter speed settings and access metering patterns in manual mode. It is also used for the adjacent AF frame selection button.

The AE/FE lock button (marked with a *) is awkwardly positioned and requires you to change your grip on the camera to access it. Adjusting aperture and shutter speed settings is easy and the on-screen display provides a moving scale as well as numerical f-stop settings, both of which change as you rotate the control dial.

 
Two methods of displaying aperture settings are provided.

On the plus side, the exposure compensation dial on the left side of the top panel will find many fans among photographers who enjoy high dynamic range (HDR) photography as it makes it easy to change exposure levels rapidly. This dial control is also quicker to use than the normal linear scale and, consequently gives photographer more flexibility with bracketing levels.

The G10's grip is a tad too shallow for users with large hands (but an improvement on the G9's), although if it was any deeper this would increase the depth of the camera body, which is already larger and heavier than its main rivals. We have a few reservations about the robustness of the battery/card compartment hatch, although the cover fits snugly and is easy enough to open and close. But weatherproof sealing is not provided so caution is required when using the camera in adverse conditions.

Some interesting refinements have been added to the focusing system, although its essential modus operandi remains unchanged from the G9. The Macro setting on the arrow pad lets you swap between close focusing and infinity. In the former mode, the G10 can focus down to 1 cm. Users can also choose between AiAF, Centre, FlexiZone and Face Detect modes in the AF Frame sub-menu and adjust the size and position of the AF frame in AiAF and FlexiZone modes. 

In AiAF mode, the nine-segment focus sensor is displayed in the centre of the screen.

The size of this grid area can be changed by toggling the Display button.

In Flexizone AF mode, a single focusing point is moved about the screen with the control dial and/or arrow pad buttons.

Pressing the AF frame button just above the arrow pad outlines the focusing zone in green. Pressing the Display button magnifies the Flexizone AF square to provide more reliable focus feedback. In manual focus mode, the centre of the frame is enlarged for focus checking and a linear graph on the right side of the LCD screen provides a rough approximation of the lens-to-subject distance. Where this isn't adequate, a new Safety MF feature lets you focus roughly with the manual mode then press the AF button to have the camera fine-tune focusing. You can also move the AF zone with the arrow pad. 

The LCD screen display in manual focus mode.

Metering modes can be selected via the right hand button above the arrow pad and users can choose between centre-weighted, evaluative and spot metering patterns. Evaluative and spot metering can be linked to the AF point when FlexiZone autofocusing is in use. This combination of controls is extremely useful and the relevant buttons are well-placed when the camera is in the hands. 

Playback
Playback mode is accessed by pressing a button just above the top right corner of the LCD monitor. Pressing this button also switches the camera on in playback mode (without extending the lens).  You can toggle forwards and backwards through shots with the horizontal arrows on the arrow pad or by rotating the control dial and zoom in and out with the zoom lever. Up to 10x playback zoom magnification is supported.

For viewing movies, the arrow pad is used to select clips while the Func./Set button initiates playback and pauses play. You can switch between showing and hiding the playback progress bar by pressing the Display button. The arrow pad buttons can also be used to control playback speed for movie clips and slow motion playback is supported.

For still images, the playback options include single image or thumbnail view with nine images per screen. Focus Check display lets you check facial expressions and identify faces selected in the Face Detect mode. White frames are superimposed on detected faces or locations where the camera has focused while grey frames appear in positions where faces were detected in playback.

An orange frame identifies the main face detected. This face is enlarged at the bottom right corner of the frame. Pressing the zoom lever magnifies this face and you can scroll to other faces in the shot with the arrow pad buttons. Where more than one focus area is detected, you can switch between AF frames by pressing the Func./Set button.

The G10 supports the standard Canon frame jumping function and includes jump by 10 or 100 images, jump to a shot date, category, folder or movie clip. Jump search is initiated by pressing the metering button and you can show or hide image data by pressing the Display button. Images can be marked as Favourites or allocated to one of six Categories (People, Scenery, Events plus three user-programmable categories).

Images can be deleted individually or all shots on the memory card can be erased simultaneously and you can protect individual shots against accidental deletion by selecting Protect in the Playback menu. DPOF tagging for automatic printing is also provided.

Automated playback is provided for slideshows, and images can be selected by date, category, folder or type.  Three transition effects are provided. In-camera red-eye correction is available, along with i-Contrast dynamic range adjustment in playback mode. The ten My Colours effects supported in the Function menu can also be applied to JPEG images post-capture (but not to raw files). Images can be re-sized to 1600 x 1200, 640 x 480 or 320 x 240 pixels for emailing or posting on websites.

Other playback functions include adding sound bites up to one minute long to still images. Images can also be deleted individually, as a group by setting a range of shots, by date, by category or by folder. You can also assign images to a new folder and re-set the file number to count up from one for each new set of shots (or new folder).
The playback menu also includes a Rotate function that can be used to automatically rotate vertical shots or rotate images manually in 90 degree steps. Movie clips can be edited in one-second increments but the only editing function appears to be the ability to trim clips. 

Software
The G10 comes bundled with the standard Canon Digital Camera Solution Disk (version 38.1 was supplied with the review camera), which we have covered in other Canon camera reviews. It contains latest versions of Canon's digital photography software suite for Windows and Mac computers, which include Digital Photo Professional, EOS Utility, ZoomBrowser and ImageBrowser, and PhotoStitch. 

Performance
The test camera turned in a respectable autofocus performance with fast and accurate focusing under most lighting conditions and only minor slowing at night and when contrast was low - particularly when the AF-assist beam was enabled. Manual focusing was easy to achieve, thanks to the enlargement of the focusing frame.  

The built-in image stabiliser allowed us to use shutter speeds as slow as 1/8 second without blurring close-up shots. Auto exposure performance was consistently good with most subject types and we encountered very few problems with backlit subjects when using normal shooting strategies.

The i-Contrast setting successfully lightened shadowed areas in contrasty shots with only a small increase in image noise. It also returned some highlight detail. However, other areas in the frame were also slightly lightened. This function can only be used with JPEG images and we found the same controls could be achieved with more subtlety when converting raw files into TIFF format for editing.

When we embarked on our tests of the G10 we had low expectations of its resolution performance because of the relatively small size (less than 2 microns square) of the photosites on its sensor. But the test camera delivered a huge surprise. Somehow Canon has managed to extract not only superior JPEG resolution from the G10's image files - but also provided raw files that rate higher in Photo Review's Imatest test than many of the DSLR cameras we've tested this year. The tables below show the results of our tests on JPEG and Raw files - and includes a comparison of the G10 with its main rivals, Nikon's Coolpix P6000 and the Panasonic DMC-LX3 at similar focal length settings.

Clearly, the lens plays a significant role in this achievement. But the new image processor also deserves considerable credit. Sadly, colour accuracy was only a little better than average although lateral chromatic aberration was generally low.  However, we found some evidence of coloured fringing in test shots taken in bright, contrasty conditions when image files were enlarged to 100%.

 
An example of coloured fringing from the edge of a shot enlarged to 100%.

Image quality also deteriorated with increased sensitivity although not to the degree we've seen in some small-sensor digicams. The table below shows the result of our Imatest tests at different ISO settings for both JPEG and Raw files.

 Luminance noise (which looks a bit like film grain) could be seen when images shot at ISO 100 were enlarged to 100%. Chroma noise (which is less acceptable) became apparent at ISO 400 and obvious by ISO 800, where resolution had begun to decline significantly and both flash shots and long exposures taken at ISO 1600 were slightly softened, although noise was less noticeable in the former than the latter.

The auto white balance setting provided full correction for the green cast of fluorescent lighting but failed to remove the orange cast of incandescent illumination. Fortunately, the tungsten and fluorescent pre-sets corrected both colour casts and manual measurement produced neutral colours under both types of lighting.

Edge and corner sharpness were generally very good in test shots. We found slight barrel distortion at the widest focal length setting but this had largely been corrected by the middle of the zoom range. Pincushion distortion at the longest focal length setting was barely detectable.

The test camera powered up in 1.4 seconds and we measured an average capture lag of 0.6 seconds, which reduced to less than 0.1 seconds with pre-focusing. Shot-to-shot times averaged 2.2 seconds for JPEG files and it took approximately three seconds to process each high-resolution JPEG image. Shot-to-shot times for raw files averaged just over 2.5 seconds, with a processing time of just under four seconds for each raw file.

A burst of 10 Large/Superfine JPEGs was recorded in 6.1 seconds. Processing appears to be done on-the-fly as it took only 3.5 seconds for the indicator light to go out. A burst of seven RAW+JPEG files was captured in 7.8 seconds, with shot-to-shot intervals of between 1.5 and 1.7 seconds. It took four seconds to complete the processing of this burst after the final shot pair was recorded.

A final word on the performance of the G10 comes from Michael Reichmann of The Luminous Landscape website, who compares images shot with the G10 and the Hasselblad H2 fitted with a 39-megapixel Phase One P45+ back in a feature article titled: You've Got to be Kidding! (No - I'm Not). You can find his interesting summary at http://luminous-landscape.com/reviews/kidding.shtml. It makes you wonder just how many pixels - and how large a sensor you actually need for images that will be viewed on-screen or printed at A3+ size.

IMATEST GRAPHS

JPEG files

CR2.RAW files

SAMPLE IMAGES

Auto white balance with incandescent lighting.

Auto white balance with fluorescent lighting.

Close-up (6.1mm focal length, ISO 100, 1/8 second at f/5.6)

Extreme close-up: (6.1mm focal length, ISO 100, 1/8 second at f/5.6)

Digital zoom (30.5mm focal length, ISO 100, 1/250 second at f/4.5)

Wide-angle (6.1mm focal length, ISO 100, 1/50 second at f/8)

Telephoto (30.5mm focal length, ISO 100, 1/40 second at f/8)

i-Contrast off; full frame

i-Contrast off; enlarged section showing shadows

i-Contrast on auto; full frame

i-Contrast on auto; enlarged section showing shadows

Night exposure: 12.2mm focal length, ISO 100, 30 seconds at f/2.8

Night exposure: 12.2mm focal length, ISO 1600, 10 seconds at f/8

Flash exposure: 30.5mm focal length, ISO 100, 1/60 second at f/4.5

Flash exposure: 30.5mm focal length, ISO 1600, 1/60 second at f/4.5

Flash portrait: 16.7mm focal length, ISO 200, 1/60 second at f/3.5

13.8mm focal length, ISO 100, 1/80 second at f/8

18.1mm focal length, ISO 400, 1/1000 second at f/4

30.5mm focal length, ISO400, 1/500 second at f/4.5

18.1mm focal length, ISO 400, 1/250 second at f/4.5

21.5mm focal length, ISO 400, 1/125 second at f/4.

Image sensor: 7.6 x 5.7 mm CCD with (14.7 megapixels effective)
Lens:  6.1-30.5mm f/2.8-4.5 zoom (28-140mm in 35mm format)
Zoom ratio: Approx. 5x optical, up to 4x digital
Image formats: Stills – JPEG (Exif 2.2), Raw; Movies - MOV (Image Data: H.264; Audio Data: Linear PCM monaural)
Image Sizes: Stills – 4416 x 3312, 3456 x 2592, 2592 x 1944, 1600 x 1200, 640 x 480, 4416 x 2480 (16:9); Movies – VGA and QVGA at 30 fps
Shutter speed range:  15 to 1/4000 second
Image Stabilisation: Optical (Lens Shift Type)
Exposure Compensation: +/- 2EV in 1/3EV increments
Focus system/range: TTL Autofocus (Single / Continuous) with Face Detect, AiAF (9-points), Centre, Flexizone modes plus Manual; range: 50 cm to infinity, macro 1-50 cm
Exposure metering: Evaluative, Centre-weighted average, Spot metering
Shooting modes: Auto, P (Program), Tv (Shutter Priority), Av (Aperture Priority), M (Manual), C1, C2, Portrait, Landscape, Night Snapshot, Sports, Special Scene (Indoor, Night Scene, Sunset, Foliage, Snow, Beach, Fireworks, Aquarium, Underwater, ISO 3200, Color Accent, Color Swap)
ISO range: Auto, High ISO Auto, ISO 80, 100, 200, 400, 800, 1600
White balance: Auto, Daylight, Cloudy, Tungsten, Fluorescent, Fluorescent H, Flash, Underwater, Custom 1, Custom 2
Flash modes/range (ISO auto): Auto, on, off, Red Eye Correction, Red Eye Reduction, Slow Synchro, Second Curtain Synchro, FE Lock, Safety FE; range - 30 cm - 4.6 m (W) 50 cm - 2.8 m (T)
Sequence shooting:  Approx 1.3 shots/sec; AF Approx 0.7 shots/sec; LV Approx 0.7 shots/sec (Large/Fine)
Storage Media: SD/SDHC
Viewfinder: Real-image optical zoom viewfinder with dioptric adjustment
LCD monitor: 3.0 inch LCD monitor with wide viewing angle and high resolution (approx 461,000 dots)
Power supply:  NB-7L rechargeable lithium-ion battery
Dimensions (wxhxd): 109.1 x 77.7 x 45.9 mm (ex. protruding parts)
Weight: Approx. 350 grams (without battery and card)