Timing & Performance

Overall performance is roughly the same as the G7, which is generally speaking a good thing - in most respects the G7 was a very speedy camera. That said, I'd hoped Canon would use the G9 upgrade as an opportunity to improve on the slightly under-par shutter lag when using the LCD and to speed up the focus (particularly in low light and at the long end of the zoom). Whilst side by side tests showed that the G9 is marginally faster at finding focus it's still far from class-leading.

The focus speed is perfectly acceptable in undemanding shooting conditions, especially given the huge zoom range, but there are faster cameras on the market - even the S5 IS, with twice the zoom range, consistently beats it at the wide end of the zoom. The G9's autofocus is actually quite slow in low light or macro mode. Shutter lag when using the LCD is also a little disappointing (though to be fair I didn't personally notice any problems when out shooting; I don't really 'do' action). This is down to the lag in the live view itself (which is around 0.07 secs) - the time between pressing the shutter and taking the picture is a very short 0.05 seconds (approx) - so if you need to use the G9 on a 'hair trigger' - don't use the LCD screen. Note that the shutter lag with flash (one the G7's problem areas) has been improved - down from 0.5 seconds to around 0.3 seconds.

The larger files created by the 12MP sensor have also impacted on the continuous shooting speed, which now tops out at around 1.5 frames per second (the G7 managed 2.0 fps), though again this will only be of concern if you shoot a lot of 'action' - and there are plenty of cameras out there better suited than this one to that particular type of photography.

On a more positive note the G9 is one of the only compact camera we've ever used that offers a genuinely usable RAW mode; shot to shot times are 3.0 seconds at worst (including focus time) and you can even shoot continuously at around one shot every 1.1 seconds in RAW mode. That's pretty impressive buffering for a non-SLR camera.

Timing Notes

All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 4000 x 3000 Super-Fine JPEG image (approx. 5,300 KB per image). The media used for these tests was a 1.0GB SanDisk Extreme III SD card.

Action	Details	Time, secs
Power: Off to Record		1.2
Power: Off to Play	Image displayed	1.3
Power: Record to Off	Lens retracted and all activity ceased	1.6
Power: Play to Off	When buffer is empty (lens extended)	1.4
Power: Play to Off	When buffer is empty (lens already retracted)	< 0.2
Record Review	Image displayed	0.8
Mode: Record to Play		1.7
Mode: Play to Record		~ 1.3
Play: Magnify	To full magnification (10x)	0.9
Play: Image to Image	Time to display each saved image (fade effect transition)	~ 0.5
Play: Image to Image	Time to display each saved image (no effect) *1	~ 0.3
Play: Thumbnail view	3 x 3 thumbnails	0.5

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 1.0GB SanDisk Extreme III SD card. Shutter speed was kept above 1/200 sec during these tests.

Continuous drive mode

The G9 has two continuous shooting modes (standard and AF-continuous), both of which allow you to shoot pretty much indefinitely (we gave up counting after about 70 shots) with a fast card. The Continuous AF mode shows the normal live preview between frames (and attempts to refocus between shots), but the normal Continuous mode only shows a very brief review image after each shot (no live preview), and the focus is fixed after the first shot. It's worth noting that the figures below (and those quoted by Canon) are only for ISO settings of under 400; at higher ISO's the frame rate drops to around half these values.

Although the performance is a step down from the G7 it's not a bad showing at all, and the fact you can shoot at a reasonable rate in RAW mode is very impressive - as is the ability to shoot almost indefinitely at 1.1fps with the flash turned on (though this only works at short distances and in fairly good light).

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 went out. This means the timings also include the camera's processing time and as such are more representative of the actual time to "complete the task". The media used for these tests was a 1.0GB SanDisk Extreme III SD card.

The G9 can process and save a 5MB plus JPEG in around 1.2 seconds, and more impressively a 12.5MB RAW file in under 3.0 seconds, leaving us in no doubt that Canon has not only increased the buffer size, but has beefed up the entire image pipeline, producing performance that, with a fast card, is excellent.