Canon A640 Performance

Timing and Performance

Canon A640 Timing
Good to average speed for a consumer camera.

Power on
to first shot
1.4 seconds
Time it takes for LCD to turn on and lens to deploy.
1.6 seconds
How long it takes to retract lens and stow in your pocket.
Buffer clearing time
1.29 second
(Large/Fine JPEG,
Unlimited shots in
continuous mode)
Worst case buffer clearing time.* This is the delay after a set of shots before you can remove the card. Some cameras won't retract their lenses and shut down until the buffer is cleared.
Mode switching
Play to Record,
first shot
1.0 seconds
Time until first shot is captured
Record to play
2.7 seconds
Time to display a large/fine file immediately after capture
recorded image
1.3 second
Time to display a large/fine file already on the memory card.
Shutter response (Lag Time):
Full Autofocus Wide
0.58 second
Time from fully pressing shutter button to image capture, zoom lens at wide angle position.
Full Autofocus Stele
0.68 second
Time from fully pressing shutter button to image capture, zoom lens at telephoto position.
0.065 second
Time to capture, after half-pressing and holding shutter button.
Manual focus
0.20 second
For most cameras, shutter lag is less in manual focus than autofocus, but usually not as fast as when the camera is "prefocused"
Cycle time (shot to shot)
Single Shot mode
Large Fine JPEG
1.56 seconds
Time per shot, averaged over 20 shots
Single Shot mode
640x480 JPEG
1.57 seconds
Time per shot, averaged over 20 shots
Early shutter
Some cameras refuse to snap another shot if you release and press the shutter too quickly in Single Shot mode, making "No" the preferred answer
Continuous mode
Large Fine JPEG
0.77 second (1.29 frames per second);
No limit w/fast card*;
~2 seconds to clear
Time per shot, averaged over buffer length or 20 shots, whichever came first
Continuous mode
640x480 JPEG
0.79 second (1.27 frames per second);
No limit w/fast card*;
~2 seconds to clear
Time per shot, averaged over buffer length or 20 shots, whichever came first
Flash recycling
5 seconds
Flash at maximum output
Download speed
Windows Computer, USB 2.0
1,042 KBytes/sec
Typical Values:
Less than 600=USB 1.1;
600-770=USB 2.0 Low;
771-4000=USB 2.0 High
*Note: Buffer clearing times measured with a Kingston Ultimate 120x SD memory card. Slower cards will produce correspondingly slower clearing times. Slow cards may also limit length of bursts in continuous mode.

The Canon A640's performance is generally faster than average. Startup and shutdown speeds are above average. Shutter response is a bit faster than average but not dramatically so. Shot-to-shot cycle times and continuous-mode speeds are above average, too. Even the flash, which is pretty powerful, takes just five seconds to recharge after a full-power shot, about average for any digicam flash. On the other hand, connected to a computer or printer with USB 2.0, download speeds are very fast, pretty much eliminating the need for an external reader. Bottom line, while not a first choice for sports or other really fast-paced action, the A640 is responsive enough (particular at wide angle lens settings) to handle most family photo opportunities.

Battery and Storage Capacity

Good battery life with Alkaline disposables, excellent with NiMH rechargeables.

Battery Type
Battery Life
280 shots
(2500 mAh capacity)
500 shots

The Canon A640 uses four AA batteries for power. The table above shows the number of shots it can take with either Alkaline or NiMH batteries, based on the CIPA battery-life standard. (Based on 2500 mAh capacity cells.) A CIPA rating of 280 shots (using Alkalines, with the LCD display enabled) is pretty good, but as always we strongly recommend that you purchase a couple of sets of high-capacity NiMH rechargeable batteries and a good-quality charger, as they'll save you many times their cost over the life of the camera.

(Interested readers can find an English translation of the CIPA DC-002 standards document here. (180K PDF document))

A 32MB SD Memory Card is included with the PowerShot A640.

Image Capacity with
32MB SD Memory Card
3,648 x 2,736 Images 7
File Size 4.4MB
2,816 x 2,112 Images 11
File Size 2.9MB
2,272 x 1,704 Images 14
File Size 2.2MB
1,600 x 1,200 Images 29
File Size 1.1MB
640 x 480
Images 111
File Size 288K

We strongly recommend buying a large capacity SD/MMC memory card at least a 256MB card, preferably a 512MB one, to give yourself extra space for extended outings. (Check the shopping link above, cards are really cheap these days, so no reason to skimp.)


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