Flash Performance

The C-40Z's flash unit has a specified range of 0.8 - 3 m at wide angle and 0.25 - 1.75 m at telephoto. It performed relatively well, good power for a small unit but the camera did tend to overcompensate to keep skin tones warm, some flash images had a definite red cast.

Skin tone test: A little underexposed, a warm colour cast which will be good for skin tones but may be a little warm for other subjects. Not a bad performance for an ultra-compact flash, some drop off at the corners. Color patch test: Good exposure, good colours but there is a visible 'warm' (red) cast.

Night exposures / Noise reduction

The C-40Z employs what appears to be a very effective noise reduction system for long exposures, this system works by taking a second 'dark frame' shot after the initial exposure, it uses this dark frame to subtract stuck pixels from the image. The Olympus algorithm does seem to be fairly sophisticated, it produces very clean, noise free images with no visible 'black pits'. With noise reduction enabled the C-40Z is more than capable of taking night exposures of up to 16 seconds without visible noise.

16 sec, Noise reduction Off 16 sec, Noise reduction On

Barrel and Pincushion Distortion

The C-40Z's tiny lens performs very well from a distortion respect. It has the 'compact camera average' 1% barrel distortion at wide angle and no measurable pincushion at full telephoto.

Barrel Distortion, 1.0% @ wide angle Pincushion Distortion, 0% @ telephoto

Purple Fringing (Chromatic Aberrations)

Uh oh. Well yes, the C-40Z does suffer from chromatic aberrations. And that's a shame because a camera which is otherwise capable can so easily end up with a tainted reputation thanks to CA's. It didn't take long to find examples of chromatic aberrations in nice sunlit or strongly backlit images, our standard chromatic aberration test shot confirmed this.

Hard pressed to find evidence of chromatic aberrations in "every day" shots
Our now standard chromatic aberration test shot

Overall Image Quality / Specific Issues

Generally speaking the C-40Z did well, clean images with very little visible noise, good metering, relatively good dynamic range and vivid colour balance. There were chromatic aberrations and some trouble with moiré (below), you'd have to decide if these are major issues to you. Of the good images my argument would be with Olympus's image processing algorithms and aggressive sharpening, these can of course be tweaked in-camera but I feel it would have been better to leave the defaults fairly neutral. But once more, thanks to the availability of good control over saturation, contrast and sharpening a little tuning can provide you with your optimum 'look'.

Moiré artifacts

The C-40Z did suffer from a strange moiré artifact which only appeared on the 'edge' of a bright highlight (normally chrome or glass edge). As you can see in the examples below this artifact is visible as a yellow or magenta glow or cast around or along the highlight area. The reason we know it's associated with moiré is that its colour matches the moiré seen on our resolution chart shots (later in this review). These artifacts do unfortunately appear to be an Olympus trait, we last saw them on the C-700UZ.

Diagonal Jaggies

The C-40Z also exhibited diagonal jaggies, something we first observed on the Canon G2. This phenomenon can be seen in lines which are near to 45 degrees which are 'made up of' several joined 45 degree lines. You can clearly see this in the seam running down the center of the indicator stalk in the 100% crop below (here you can also see fringing and chromatic aberrations).