Here you can see a generated GretagMacbeth ColorChecker chart, place your mouse over any of the labels below it to see the color reproduction in that mode. Select a camera/setting combination from the 'Compared to' drop-down to comparative boxes inside each patch.
Olympus has developed a devoted following for its color reproduction, with the 'Natural' settings producing fairly saturated results with particular emphasis on blues to give very photogenic skies. There's a muted option if you want your starting point to be a little more realistic but less punchy.
Artificial light White Balance
Despite the inclusion of an external White Balance sensor, the E-620's White Balance performance is virtually identical to that of the E-520, which always gave rather 'warm' results under artificial lights.
There's the now-familiar battle to set a custom white-balance (which can only be done by configuring the Fn button to white balance preset), but all the settings can be fine-tuned in both the Amber-Blue and Magenta-Green axes.
Incandescent - Auto WB
Red: 6.8%, Blue: -8.9%, Average
Incandescent - Incandescent preset WB
Red: 3.4%, Blue: -3.7%, Average
Fluorescent - Auto WB
Red: 5.6%, Blue: -9.5%, Average
Fluorescent - White Fluorescent preset WB
Red: 6.8%, Blue: -5.3%, Average
If you are likely to be using multiple external flashguns, Olympus is the only major DSLR maker to include full, multi-zone remote control of flashes in all of its models. The E-620 can control three groups of flashes, remotely, using its built-in flash to send a command signal. This means that you can use bounced, off-camera flash if you want more flatteringly lit portraits.
Shadow Adjustment Technology
The E-620, like the E-30 before it, uses exposure adjustments and tone curves to enhance the retention of detail in the highlights of images. In addition to this, it offers Shadow Adjustment Technology (SAT), based on technologies from Apical (similar to those in Nikon's D-Lighting and Sony's DRO modes). This attempts to increase the range of tones conveyed in the final image while retaining local contrast.
The theory is that it results in images that are closer to the way the human brain perceived the scene, while the cost is that you get additional noise in shadow regions of the images. Unlike most other included software often doesn't include these dynamic range compression algorithms, Olympus Studio can apply or remove the effect of Shadow Adjust Technology from RAW files. Simply switching the 'Gradation' setting to 'Auto' will apply the effect, while any other will apply a conventional tone-curve to the whole image.
On the whole, it's a question of taste but there are plenty of situations in which an increase in noise in the shadows is an acceptable price to pay for a final image with a more balanced tonal range, so we'd be inclined to move gradation to 'Auto' in high-contrast situations. There's no harm leaving it on if you tend to shoot RAW, either - you can always use Olympus Studio to re-create the effect if you find you prefer the results to those of your chosen RAW converter.
Gradation Normal (SAT Off)
ISO 200, 1/160 sec, F3.8
Gradation Auto (SAT On)
ISO 200, 1/160 sec, F3.8
Overall Image Quality / Specifics
There's not really a lot to complain about with the E-620's images. Metering is pretty dependable in the vast majority of situations with the camera far more likely to underexpose than overexpose in the rare situations it doesn't get it right.
The color rendition, even in its 'Natural' setting, is pretty saturated compared to the competition and the default sharpening is higher than its peers to try to make the most of the detail pulled out of the file. Neither of these is particularly problematic, however - you can turn the sharpening down a fraction and we suspect a lot of people will rather enjoy the punchy, vibrant colors they get.
The only real issue we experienced (and even then, only very occasionally), was the E-620's difficulty in capturing certain shades of purple. It's an extremely minor complaint (the likelihood of most people noticing it is tiny), but is worth being aware of. Below is an example of the image as produced by the camera, compared to how I remember the scene (this is a perceptual approximation and shouldn't be taken as a measure of the camera's inaccuracy).