White Balance

The Z650 has just four white balance presets in addition to the auto default; daylight, tungsten, fluorescent and open shade. There is no manual (measured or custom) white balance function, an almost unforgivable omission (even most basic 'point and shoot' models now offer manual / custom white balance). Fortunately the Z650's auto white balance does an excellent job in most natural light situations (and not a bad job with mixed lighting either). Under tungsten (incandescent) light the results have only the slightest warm tone, but fluorescents can cause a serious color cast (no single 'Fluorescent' preset can deal with all the different tube types out there).

Incandescent - Auto WB
Red 3.5%, Blue -2.1%
Incandescent - Incandescent preset WB
Red 1.1%, Blue -4.4%
Fluorescent - Auto WB
Red 7.4%, Blue -22.9
Fluorescent - Fluorescent preset WB
Red 6.9%, Blue -7.3%

Flash Performance

Aside from some cut-off when the flash is blocked by the lens with very close subjects there's little to complain about here. 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. Our only problem was - as shown below - that there is a slight tendency to underexpose (particularly at the longer focal lengths), but it's mild, easily fixed, and does at least ensure you don't get blown-out highlights.

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

Macro Focus

The Z650's macro function gets you down to about 12cm (4.7 inches) at the wide end of the zoom, capturing an area just under 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 around four times bigger (just under 10cm across), and there is still some distortion, though less so (there is, however, noticeable corner softness). In both these shots there is also noticeable - and towards the corners fairly strong - chromatic aberration.

Wide macro - 47 x 35 mm coverage
60 px/mm (1525 px/in)
Distortion: Low to average
Corner softness: Low
Equiv. focal length: 38 mm
Tele macro - 107 x 80 mm coverage
26 px/mm (671 px/in)
Distortion: Low
Corner softness: Fairly high
Equiv. focal length: 380 mm

Barrel and Pincushion Distortion

No real problems here - 0.5% barrel distortion is well within the expected boundaries of a lens of this type, and there no measurable distortion at the telephoto end of the zoom.

Barrel distortion - 0.5% at Wide angle
Equiv. focal length: 38 mm
Pincushion distortion - 0.0% at Telephoto
Equiv. focal length: 380 mm

Specific image quality issues

First the good stuff. Images from the Z650 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. Of course the fairly high default sharpness / contrast / saturation means purists will baulk, and will want to try playing with the parameters in-camera. Exposure is good - though far from foolproof - and I reckon I got a hit rate of about 90%, with the remainder marred mainly by focus errors or camera shake at the long end of the zoom or by exposure problems caused by unusually contrasty scenes. There is a very slight tendency to underexpose, but this isn't the end of the world (it helps keep the colors nice and rich) and is easy to fix in post-processing: It is a lot better than overexposure. The need for image stabilization becomes painfully apparent when shooting at full zoom in anything but the best light, meaning you can struggle to get razor-sharp results without a tripod. Finally there is mild (very mild) vignetting and corner softness at the long end of the zoom.

Viewed on-screen the images lack the biting sharpness of the best cameras in this class (such as the Panasonic FZ series), but the appeal of the images is the rich color - deep blue skies, excellent skin tones and bright, cheerful primary tones. We found the Z650 much better at retaining highlight detail than its predecessor, and it must be stressed that for most users the results will be more than satisfactory, and the softness will have little impact on the standard postcard-sized prints most people will produce. If you're a detail freak, however, you may find the images lack the critical sharpness you demand. At higher ISO settings the combination noise, noise reduction and heavy JPEG compression (something you can't change) produces images that look very muddy, and are only really suitable for small prints.

Color fringing

Although it's worst in areas of high contrast and/or overexposure, and at the widest (F2.8) aperture, strong fringing is visible in the corners of the majority of wide angle shots.

100% crop 38 mm equiv., F2.8