White Balance

The P850 has very comprehensive white balance controls for a camera in this class. In addition to the default auto WB there are six presets; Daylight, Tungsten, Fluorescent, Cloudy, Open Shade and Sunset, one click manual white balance and no less than three custom white balance settings. Finally a neat white balance compensation function lets you fine tune color using the on-screen preview. In our tests the auto WB generally worked very well, preserving the warmth of the winter sun and representing colors pretty much as we saw them, though scenes with a predominance of a single color fooled the AWB system on occasion. Indoors the AWB coped well with incandescent light (better, in fact, than the tungsten preset), though fluorescents did produce a greenish cast, which was solved by switching to the fluo preset.

Incandescent - Auto WB
Red 5.5%, Blue -3.8%
Incandescent - Incandescent preset WB
Red 6.9%, Blue -13.6%
Fluorescent - Auto WB
Red 0.8%, Blue -13.6%
Fluorescent - Fluorescent preset WB
Red 3.0%, Blue -2.5%

Flash Performance

There's little to complain about here apart from the increasingly extended flash recycle times as the battery starts to run out. Even worse, if the flash isn't fully charged by the time you press the shutter it will take the picture anyway, without firing the flash, resulting in a totally underexposed shot. At first I thought this was a fault with my camera, but apparently it is 'normal behavior'. This means you have to be very careful when using flash with a half-empty battery.

Otherwise, exposures are excellent and color almost perfect (unusually for a built-in flash it's slightly warm, which is no bad thing most of the time). Fill flash is well balanced and the slow-sync works very well.

Skin tone
Good color, good exposure
Color chart
Slightly warm color, very slight underexposure

Macro Focus

The P850's macro function gets you down to about 10cm (3.9 inches) at the wide end of the zoom, capturing an area just over 5cm across, though there is obviously a price to pay in the form of distortion (common to most digital camera macro modes). At the telephoto end of the zoom the area captured is almost identical, though the shooting distance is increased to 90cm and the distortion almost non-existent.

Wide macro - 90 x 67 mm coverage
29 px/mm (727 px/in)
Distortion: High
Corner softness: Average
Equiv. focal length: 36 mm
Tele macro - 89 x 67 mm coverage
29 px/mm (733 px/in)
Distortion: Low
Corner softness: Low to average
Equiv. focal length: 432 mm

Barrel and Pincushion Distortion

There is noticeable barrel distortion at the wide end of the zoom, but it's unlikely to mar everyday shots, and is no worse than most of the competition. There is only the merest measurable (0.1%) pincushion distortion at the tele end of the zoom.

Barrel distortion - 1.1% at Wide angle
Equiv. focal length: 36 mm
Barrel distortion - 0.1% at Telephoto
Equiv. focal length: 432 mm

Image stabilization

The biggest problem with the DX and Z series of big zoom EasyShare cameras was the lack of image stabilization, which, combined with the inevitable noise problems associated with such a small sensor, made using the long end of the zoom difficult. The good news is that the P850 has a similar optical image stabilizer to its main competitors from the Canon, Sony and Panasonic stables. The even better news is that it seems to work very well, allowing hand held shots at three stops or so slower than would be possible without it - meaning you'll get pretty sharp shots at 1/50th of a second at the long (432mm equiv.) end of the zoom, and even dropping to as low as 1/8th produces acceptable results if you've got a fairly steady hand in the first place.

The P850 has two IS modes, 'single' (activated on half-press of the shutter) and continuous. In our tests there wasn't a huge difference in effectiveness between the single and continuous modes, though we had a higher success rate with continuous, so I'd only suggest using the single mode if you want to maximize battery life. It's worth noting that the 'single' mode doesn't work in the same way as it does on Canon and Panasonic cameras (where the IS is activated only when the shutter is actually pressed) - it simply doesn't come on until you half-press the shutter (to focus), and so is no more effective than leaving it on continuous - quite the opposite according to our tests.

Although we've no definitive test for IS systems in real-world use, I was very impressed with the P850's stabilization, which seems roughly on a par with that offered by Canon and Sony (though we still feel the Panasonic FZ cameras have a slightly more effective IS system). These tests are rather extreme - around 3 or 4 stops slower than you could safely use without IS - and in 'real life' shots - where you are maybe using a shutter speed two stops slower than normal - the system is pretty much 100% effective.

IS off 100% crop IS on (continuous mode) 100% crop
1/8 sec, 432mm equiv. Hand held.
IS off 100% crop IS on (continuous mode) 100% crop
1/8 sec, 432mm equiv. Hand held.
IS off 100% crop IS on (continuous mode) 100% crop
1/15 sec, 432mm equiv. Hand held.

Specific image quality issues

First the good stuff. Images from the P850 have typical Kodak color - rich, saturated and vibrant, yet very natural, meaning most of the target audience will be overjoyed at the bright punchy prints they get without any post-processing. Exposure is good - though far from foolproof - and I reckon I got a hit rate of about 80%, with the remainder marred mainly by focus errors or by exposure problems caused by unusually contrasty scenes.

On the downside, as noted elsewhere in this review, the images lack biting sharpness, and there is a tendency for fine detail to be muddied by the in-camera processing, which leads to a loss of texture in scenic shots. Inevitably there is some clipping of highlights, but this doesn't seem to be as much of a problem as we've seen with some other 5MP cameras.

Chromatic Aberration

Not a huge problem, though you can see some CA (and some purple fringing) in bright, contrasty scenes.

100% crop 36 mm equiv., F2.8