Timing & Performance

Canon PowerShot G5 owners really won't notice a big performance improvement with the G6, and that alone is a disappointment. Startup is quicker, by about three quarters of a second, but it's still three seconds (not the slowest in our 7mp group test, but not the fastest either). Shutter release lag using the LCD monitor was a surprise as it seemed and measured slower than the G5. Auto Focus wasn't awful but neither was it particularly fast, especially when compared to cameras like the Sony DSC-V3, the G6 always managed to lock without hunting at similar focus distances but this still means a 0.6 second or slower delay on top of the shutter lag. Continuous shooting was just as much a mixed bag, good buffer, poor speed. Overall the G6 simply isn't as fast as you'd expect considering its prosumer image and heritage.

Timing Notes

All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 3072 x 2304 Fine JPEG image (approx. 2,600 KB per image).

Media used for these tests

• 1 GB SanDisk Extreme III CF card (Type I)
• 1 GB Lexar Pro 80x CF card (Type I)

Lag Timing Definitions

Half-press Lag (0->S1) Many digital camera users prime the AF and AE systems on their camera by half-pressing the shutter release. This is the amount of time between a half-press of the shutter release and the camera indicating an auto focus & auto exposure lock on the LCD monitor / viewfinder (ready to shoot).	(Prime AF/AE)
Half to Full-press Lag (S1->S2) The amount of time it takes from a full depression of the shutter release button (assuming you have already primed the camera with a half-press) to the image being taken.	(Take shot, AF/AE primed)
Full-press Lag (0->S2) The amount of time it takes from a full depression of the shutter release button (without performing a half-press of the shutter release beforehand) to the image being taken. This is more representative of the use of the camera in a spur of the moment 'point and shoot' situation.	(Take shot, AF/AE not primed)

Continuous mode

The tables below show the results of our continuous shooting test, indicating the actual frame rate along with maximum number of frames and how long you would have to wait after taking the maximum number of frames before you could take another shot. Media used for these tests was a 1 GB Lexar Pro 80x CF card. Shutter speed was kept above 1/250 sec during these tests.

Continuous Low speed

Continuous High speed

The fact that the G6 can shoot RAW continuously and that it appears to have a fairly large buffer are no consolation for the lack of shooting speed. In Low speed mode we see an average of around 0.7 fps (one shot every 1.4 seconds), in High speed just 1.6 fps. This is a step back from the PowerShot G6 and is certainly behind competitive cameras. I'm also fairly surprised at the discrepancy between our measured performance and those quoted in the camera specifications (1.0 vs. 0.7 fps and 2.0 vs 1.6 fps). There's little point labeling 0.6 fps as 'continuous shooting'.

* UPDATE: Canon are telling me that their specified figures are for the LCD switched off, while I didn't take that into account when writing the above comments all cameras are tested in the same way and the G6 should be able to perform in a similar way to other digital cameras with the LCD on.

File Write / Display and Sizes

Timings shown below are the time taken for the camera to process and "flush" the image out to the storage card, the timer was started as soon as the shutter release was pressed and stopped when activity indicator beside the viewfinder had gone out. This means the timings also include the cameras processing time and as such are more representative of the actual time to "complete the task". (It's also possible they're slightly inaccurate because of the G6's blinking indicator).

Media used for these tests

• 1 GB SanDisk Extreme III CF card (Type I)
• 1 GB Lexar Pro 80x CF card (Type I)

File sizes

The G6 returns to its live view approximately 1.6 seconds after pressing the shutter release (or longer if record review is enabled), the write times shown above are for the camera to complete writing the file in the background. Unlike some cameras the G6 can also write RAW files in the background and so you can get on with taking the next shot uninterrupted. I wasn't particularly impressed with the processing / write times, it's impossible to say how much of the 4.5 seconds to write a JPEG Super-Fine is taken up with processing but it's still twice the time required by some competitive cameras (though this time doesn't stop you shooting).

Low Light Auto Focus

This test is designed to measure the minimum amount of light under which the camera can still focus. The focus target is our lens distortion test chart (shown here on the right), camera is positioned exactly 2 m (6.6 ft) away.

Light levels are gradually dropped until the camera can no longer focus. This is carried out at both wide angle and telephoto zoom positions (as more light reaches the focusing systems with a larger aperture).

With its AF assist lamp the G6 manages to focus in complete darkness (as we'd expect), what's quite impressive is how quickly it can lock and that it really doesn't need to have the lamp on for long. Indeed a re-focus at a similar focus distance results in a quick flash of the AF lamp and you're locked. Without the lamp the G6 needs a moderate amount of light to focus on our test chart.

Battery life

We ran the camera through our new battery life test. This test is designed to be fair and comparative to each camera and battery type:

• Take 4 shots without flash
• Wait 2 minutes (50% of the time powering the camera off)
• Take 1 shot with flash
• Wait 1 minute
• Repeat

Batteries are fully discharged and recharged before the test and all cameras were reset to their factory default settings. Here are the results:

We weren't that surprised to see the G6 challenging the Olympus C-8080 WZ for our top spot, the G5 lasted almost five hours on its lower capacity battery, the newer battery and improvement in power savings delivered an hour more shooting in our test, a truly impressive five and a half hours.