Timing & Performance

Like all recent IXUS/SD models the SD850 feels very responsive, with the DIGIC III imaging processor doing a good job powering the camera's processes. The camera takes about a second to get ready for shooting and focusing is pretty snappy at around 0.4 sec (although naturally this can slow down in poor light, especially at the tele end of the lens). The shutter lag is pretty 'standard' at 0.1 seconds when using the LCD; not specifically quick, but in line with most of the competition. If you turn off the LCD and use the viewfinder the lag drops to 0.07 sec. So there is a slight (0.03s) lag in the live preview (something common to most cameras).

Timing Notes

All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 3264 x 2448 Fine JPEG image (approx. 4,600 KB per image). The media used for these tests was a 1.0 GB Sandisk Extreme III card.

Action	Details	Time, secs
Power: Off to Record	With startup animation disabled	1.0
Power: Off to Play	Image displayed	1.0
Power: Record to Off	All activity ceased	1.5
Power: Play to Off	When buffer is empty, lens retracted	0.2
Power: Play to Off	When buffer is empty, lens extended	1.1
Record Review	Image displayed	0.9
Mode: Record to Play		1.7
Mode: Play to Record		1.6
Play: Magnify	To full magnification (10x)	0.9
Play: Image to Image	Time to display each saved image	0.3 *1
Play: Thumbnail view	3 x 3 thumbnails	0.1
Zoom from Wide to Tele	35 to 140 mm (4 x) full speed	1.5
Half-press Lag (Focus time)	Wide angle, single shot focus	~0.4 *2
Half-press Lag (Focus time)	Telephoto, single shot focus	~0.4 *2
Pre-focus Lag (S1>S2)	LCD live view	~0.1
Pre-focus Lag (S1>S2)	Viewfinder	~0.07
Full-press Lag (0->S2)	LCD live view, wide angle	~0.6
Off to Shot Taken	LCD live view	~1.8
Shot to Shot	Flash off	~1.3
Shot to Shot	Flash on ( red eye reduction on / off)	~3.2 / ~ 2.5

Continuous drive mode

Like most SD/Ixus series cameras the SD850 has a single continuous shooting mode that offers around 1.3 frames per second at all file size / quality settings. You can't see a preview when shooting bursts, but there is a brief review image displayed after each exposure. There appears to be no limit to how many pictures you can take in a single burst with a fast card (well, we gave up after a few minutes).

Although it's unlikely that many users of a camera such as this will need to shoot such long sequences, it's nice to know you can if you want to. 1.3fps is actually a decrease relative to the SD850's predecessor (The SD700's 2fps) - as ever increasing sensor resolutions (and therefore file sizes) take their toll.

File writing / playback performance

The SD850 takes around 0.9 seconds to save a 4MB 8MP/Super Fine JPEG; pretty good going for a camera of this type - the SD850 will certainly benefit from using faster cards. Playback is also very speedy, with full size images taking only 0.4 sec to display (if you use the fancy transition options it takes a little longer to scroll through images, but it sure looks nice). If you want to whiz through hundreds of saved shots you can hold down the left or right arrow key and the SD850 will scroll through low res previews of the images on your card at about 10 per second.

Battery life

Battery life, like most models in the SD range, is on the low side of average; approx 230 shots (CIPA standard) per charge, with the saving grace being that the majority of the power is drawn by the fairly large screen, and if you switch it off and use the optical viewfinder you can extend the battery life to as much as 700 shots per charge. Remember that using the continuous mode image stabilization or using the flash a lot will reduce these figures.