Photographic tests

White balance

The SD800 IS has five white balance presets (daylight, cloudy, tungsten, fluorescent and fluorescent H) in addition to the default auto white balance. There is also a 'custom' white balance setting, which allows you to point the camera at a white or gray object and set the white balance manually. The custom white balance setting is remembered even if you turn the camera off. In normal outdoor shooting the auto white balance works perfectly (as confirmed by our studio tests). Indoors it's a bit more hit and miss, as we've seen with most Canon PowerShots incandescent (tungsten) lighting causes a fairly strong orange color cast (though switching to manual gives a pretty neutral result). If you don't like the warm tone, you need to switch to custom WB.

Auto White Balance	Fluo Preset	Auto White Balance	Incandescent preset
Fluorescent light - Auto white balance average, Preset white balance average		Incandescent light - Auto white balance poor, Preset white balance average

Flash

The SD800's built-in flash has a quoted working range of 0.5m - 4.0m (1.6 - 13 ft) at the wide end of the zoom and 0.5m - 2.0m (1.6 - 6.6 ft) at the tele end, which is a bit on the underpowered side, and we found that the SD800 tends to use a rather high ISO setting if your subject is more than a few feet away. That said, exposure is generally excellent and flash recycling is pretty nippy (particularly if you turn the red eye reduction off). The AF illuminator works very well at distances of up to around 2m. Click here for flash test chart

Skin tone - Excellent color and exposure.

Macro

As is common to most compact digital cameras the SD800's macro mode is most effective at the wide end of the zoom, where you can get as close as 3cm - not bad at all for an 'ultra-compact', capturing an area 44mm across. This isn't quite as good as the SD700, presumably because of the wider lens. At the long end of the zoom the performance is less impressive - 30cm subject distance capturing an area just over 10cm wide - but still pretty useful. There is inevitably some distortion when shooting very close up at the wide end, but it is not too strong, and certainly less so than many of its competitors. If you look at either of the samples below you'll also see some chromatic aberration, though to be fair this is something we only really saw in the lab, not the real world.

• Click here for wide macro test chart
• Click here for tele macro test chart

Movie mode

Like the SD700, the SD800 offers a maximum movie size of 640x480 pixels - enough to fill most television screens at 30 frames per second. It also offers options to shoot at smaller sizes and lower frame rates. There's a 'high frame rate' option that shoots 320x240-pixel movies at 60fps. Overall quality is excellent, with movies very smooth and showing few compression artifacts. The AVI files are large - at the best quality setting (640x480 / 30fps) you're burning around 1.7MB every second, so if you intend to shoot a lot of movies you're going to need to invest in some big, fast SD cards. The old 1GB limit has now been lifted to 4GB too. You cannot use the optical zoom during filming, but you can use the digital zoom.

Sample movie: 640 x 480 pixels @ 30 fps File size: 10.65 MB, 5.2 secs Click on the thumbnail to view the movie (caution: large file!)

Resolution

Resolution is marginally better than the SD700 IS (though not so as you'd notice in a print) and is similar to most of the better cameras in this class. The results look slightly softer and slightly more sharpened than the SD700, but again this is only if you're viewing at 100% on screen. As you move towards the very highest frequencies there is a very small amount of moiré visible, but overall there's little to complain about here.

Crops
Click here for the full resolution test chart	Horizontal LPH Absolute resolution 1450 LPH Extinction resolution 1700 LPH	Vertical LPH Absolute resolution 1500 LPH Extinction resolution 1900 LPH * *moiré visible

Distortion and other image quality issues

Despite the wider lens the SD800IS exhibits only moderate distortion at the wide end of the zoom - 1.2% barrel distortion (click here for test chart) - nothing to worry about on a camera of this type. On a more positive note there is only the slightest (0.2%) measurable distortion at all at telephoto end (click here for test chart).

General comments

Overall impressions of the output from the SD800 IS are that there are few surprises; in 'normal' shooting conditions it consistently produces sharp, bright, clean results that will give the typical user little if anything to complain about - particularly if they're producing prints or viewing on-screen without zooming in to a pixel level. Exposure, color and focus are excellent, and aside from the minor issues mentioned below things are as good as you can expect from an ultra compact in 2007.

Of course if you are the type of person that's looking at images at a pixel level there are some caveats to the comments above. Viewed at 100% on-screen there is a lack of biting sharpness, some corner softness at the wide end of the lens and a distinct loss of fine low contrast detail at anything over ISO 100 (see next page). There is also some mild fringing and the usual problems with highlight clipping in very contrasty conditions. The default contrast and sharpening are a little too high for my liking, but at least Canon allows you to control these parameters in-camera.

Highlight clipping / contrast issues

Like virtually every compact camera we've ever tested the combination of limited dynamic range and rather steep tonal curve (contrast) means the SD800 IS can - and does - clip highlights when shooting in bright, contrasty situations. This isn't helped by the SD800's slight tendency (shared with several recent Canon compacts) to overexpose such shots.

It's no worse a problem than most other small sensor cameras, but it is a problem. Of course you can use AE compensation to bring down the exposure a little (or live with the clipping, which is only a problem in fairly specific types of shot) - but that kind of goes against the 'point and shoot' ethos of the IXUS/Elph range.

100% crop	28mm equiv., F2.8
100% crop	28mm equiv., F2.8

Fringing

The SD 800 IS exhibits some very mild and very diffuse purple / blue fringing, though to be fair you only get it at the edge of overexposed areas, and we had to search carefully through over 500 shots to find the examples here.

100% crop	105mm equiv., F5.6

Corner softness

Perhaps unsurprisingly for a tiny lens that goes unusually wide - and in common with several IXUS / Elph models - the SD800 IS does suffer a little from a loss of sharpness as you move towards the edge of the frame, most specifically in the corners at the widest zoom setting. As we've seen before with models in this range there's one corner that's worse than the others (though of course there's no way of knowing if this is only the sample I had for testing). I only really noticed the softness in a small proportion of real world shots, and it's hardly going to matter to most buyers of this type of camera, but it is there, and worth knowing about if these things bother you.

100% crop	28mm equiv., F2.8