Compared to the Olympus C-40Z

Most of the major manufacturers have been quick to jump on the four megapixel bandwagon, and it hasn't taken long for a selection of four megapixel digital cameras to appear on the market. The S40's (current) major competition comes from Olympus's C-40Z and so we be using it for comparison here. Note that this is the same comparison made in the C-40Z review and that this comparison has been updated since the publication of this review (now using a full production C-40Z).

Because of the S40's unique ISO 50 option we must also compare the difference between this setting and the 'typical' ISO 100 offered by the C-40Z. Below you'll find two sets of comparisons at both ISO 50 and ISO 100.

Scene comparison, Canon S40 @ ISO 50

Cameras were reset to factory defaults. Aperture priority was used on both cameras to use an aperture of F5.6 (or as close as possible). White balance was set to Manual Preset. Lighting - 2 x 800W studio lights with dichroic daylight filters bounced off a white ceiling reflector.

Olympus C-40Z	Canon PowerShot S40
ISO 100, 1/3 sec, F5.6	ISO 50, 1/2 sec, F5.6
Olympus C-40Z	Canon PowerShot S40

It's fairly clear to see a difference between the two companies approach to the actual decoding of the data from the CCD (Bayer Interpolation) and subsequent sharpening. The C-40Z in places seems a little 'fuzzy' with some detail missed (note the crop of the Martini label), it also appears to use a slightly less sophisticated processing algorithm which leads to some 'double height' jaggies along diagonals (yellow crayon in the last crop and the top of the watch are good examples). The S40 on the other hand seems more detailed in some of the crops and smoother in others, although there are a few dot artifacts around the lines on the ruler crop.

Colour wise both cameras are fairly similar, the only notable difference is in the way they handle the yellow and orange crayons in the last crop (the S40 being a little better). From a resolution point of view the S40's lens does seem to be better than the C-40Z's towards the edge of the frame.

It's also worth noting that there's only 2/3 EV difference between the two cameras exposures despite being set at ISO 100 and ISO 50 respetively, this hints that the C-40Z's ISO 100 is probably closer to ISO 80.

Scene comparison, Canon S40 @ ISO 100

Cameras were reset to factory defaults. Aperture priority was used on both cameras to use an aperture of F5.6 (or as close as possible). White balance was set to Manual Preset. Lighting - 2 x 800W studio lights with dichroic daylight filters bounced off a white ceiling reflector.

Olympus C-40Z	Canon PowerShot S40
ISO 100, 1/3 sec, F5.6	ISO 100, 1/6 sec, F5.6
Olympus C-40Z	Canon PowerShot S40

Again, the same observations from the ISO 50 comparison apply, here however it's clear to see a little more noise visible in the S40 shot, particularly on flat gray areas (such as the ruler).