"Picky Details" for the Canon PowerShot A620 digital camera
(Timing, Power, and Storage Info)
Timing
When you press the shutter release on a camera, there's usually a lag time or delay before the shutter actually fires. This corresponds to the time required for the autofocus and autoexposure mechanisms time to do their work, and can amount to a fairly long delay in some situations. Since this number is rarely reported on (and even more rarely reported accurately), and can significantly affect the picture taking experience, I routinely measure both shutter delay and shot to shot cycle times for all cameras I test, using a test system I designed and built for the purpose. (Crystal-controlled, with a resolution of 0.001 second.) Here are the numbers I collected for the Canon PowerShot A620:
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(secs) |
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| Power On -> First shot |
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LCD turns on and lens extends forward.
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| Shutdown |
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First time is time to retract lens, second time is
worst-case buffer-clearing time.
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| Play to Record, first shot |
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Time until first shot is captured.
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| Record to play |
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First time is that required to display a large/fine
file immediately after capture, second time is that needed to display
a large/fine file that has already been processed and stored on the
memory card.
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| Shutter lag, full autofocus |
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First time is at full wide-angle, second is full telephoto. |
| Shutter lag, prefocus |
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Time to capture, after half-pressing and holding down the shutter button.
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| Shutter lag, flash |
0.63
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Metering pre-flash usually slightly increases shutter delay. |
| Shutter lag, manual focus |
0.276
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Usually faster than autofocus, but slower than the "prefocused" case. |
| Cycle Time, max/min resolution |
1.20 / 1.21 |
First number is for large/fine files, second number is time for "TV" mode (640x480) images. Times are averages. In both modes, shoots this fast continuously, clearing the buffer after each shot. |
| Cycle Time, Flash exposures | 6 | (Flash at maximum power output) |
| Cycle Time, continuous mode, max/min resolution | 0.50 / 0.52 (1.99 / 1.93 fps) |
First number is for large/fine files, second number is time for "TV" mode (640x480) images. Times are averages. In both modes, shoots this fast continuously, clearing the buffer after each shot. |
The A620 is fairly fast on its feet for a consumer digital camera, though some of its performance is just about average. Start-up is quick, and shutter response is good at both wide angle and telephoto lens settings. (At 0.51 second, very fast at wide angle, and at 0.72 second, still somewhat better than average at telephoto.) Prefocused (half-way holding down the Shutter button), the A620 is very quick, at 0.073 second. Normal large/fine JPEG cycle times are about average, and its Continuous speed is just a little slow, but not bad for its price range. However, the strength of the A620's Continuous mode is that, given a sufficiently fast memory card, the camera can capture an unlimited number of frames this fast, without stopping to clear the buffer. (The figures above were measured with a 133x Kingston memory card, continuous mode performance may be worse with slower cards. And before anyone writes, yes, you'll naturally always be limited by the capacity of the memory card!) Connected to a computer, download speeds are very fast. Bottom line, the Canon A620 is perfectly suitable for family photos of zippy children and pets, as well as most average situations, including most sporting events.
Power
The Canon PowerShot A620 uses four AA batteries for power, and ordinary alkaline batteries are included with the camera.
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(@5.5 volts on the external power terminal) |
(four 1600 mA cells) |
| Capture Mode, w/LCD |
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| Capture Mode, no LCD |
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| Half-pressed shutter w/LCD |
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| Half-pressed w/o LCD |
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| Memory Write (transient) |
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| Flash Recharge (transient) |
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| Image Playback |
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The table above shows maximum run times based on our power measurements and a "standard" set of 1600 mAh rechargeable NiMH AA cells. (Run times with the current highest-capacity NiMH batteries would be even longer.) These are really excellent run times, the camera consumes little enough power that you probably could run it from alkaline cells if you wanted to. We still strongly recommend good-quality NiMH rechargeable batteries and a good-quality charger, as they'll save you many times their cost over the life of the camera.
Storage Capacity
The Canon PowerShot A620 stores its photos on SD / MMC memory cards, and a 32 MB card is included with the camera. (I strongly recommend buying at least a 128 MB card, preferably a 256 MB one, to give yourself extra space for extended outings.) The chart below shows how many images can be stored on the included 32 MB card at each size/quality setting.
| Resolution/Quality 32 MB Memory Card |
Fine | Normal | |
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| 3072 x 2304 | Images (Avg size) |
10 3.2 MB |
16 2.0 MB |
33 959 KB |
| Approx. Compression |
7:1 | 11:1 | 22:1 | |
| 2592 x 1944 | Images (Avg size) |
12 2.6 MB |
21 1.5 MB |
43 744 KB |
| Approx. Compression |
6:1 | 10:1 | 20:1 | |
| 2048 x 1536 | Images (Avg size) |
18 1.7 MB |
33 943 KB |
66 479 KB |
| Approx. Compression |
6:1 | 10:1 | 20:1 | |
| 1600 x 1200 | Images (Avg size) |
30 1.1 MB |
53 595 KB |
101 314 KB |
| Approx. Compression |
5:1 | 10:1 | 18:1 | |
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Images (Avg size) |
113 281 KB |
176 182 KB |
116 KB |
| Approx. Compression |
3:1 | 5:1 | |
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Download Speed
The Canon PowerShot A620 connects to a host computer via a USB interface. Downloading files to my Sony desktop running Windows XP (Pentium IV, 2.4 GHz), I clocked it at 1979 KBytes/second. (Cameras with slow USB interfaces run as low as 300 KB/s, cameras with fast v1.1 interfaces run as high as 600 KB/s. Cameras with USB v2.0 interfaces run as fast as several megabytes/second.)
A620 Test Images
A620 Specifications
A620 "Picky Details"
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