The DC280 has an interesting feature which enables the camera to switch automatically to a higher ISO when required (low light - ISO 200).
A quick note for those who don't understand how digital cameras "replicate ISO". When a manufacturer designs the camera they'll typically use a CCD which, combined with a signal amplifier produces a light sensitivity somewhere near ISO 100 (that is the same exposure value as ISO 100 film would require), to increase the ISO you simply "turn up the volume" on the signal amplifier.. The trade off is that you also amplify noise and can end up with a grainy image.
Measured light (using a flash meter) was 5.2EV, Center Weighted Metering. ISO values are according to EXIF headers.
|Auto ISO: OFF
ISO 100, 1/6s, F3.8
Auto ISO: ON
Here you can see that the exposure was "pushed" from 1/6s to 1/8s but at the expense of added noise. That combined with the odd JPEG encoding errors from the DC280 makes very low light images pretty grainy.
JPEG Compression qualities
Here's a 200% blow-up of the same shot taken at differing JPEG qualities, you can start to see the JPEG artifacts creeping in at BETTER quality and they're easily visible at GOOD quality. The same image at STANDARD (896 x 592) resolution.
|BEST 1760 x 1168
|BETTER 1760 x 1168
|GOOD 1760 x 1168
Overall I wasn't that happy with the JPEG compression in the DC280, I saw the same flat area artifacts which I found on the DC265 and I've seen in DC240 images, the obvious 8x8 blocking and "surrounding detail" artifacts can be found even in the BETTER quality images which is a pity because the camera can take really very nice shots.
The DC280 has the ability to control the internal sharpening on three levels, SOFT (some softening of image), NORMAL (no sharpening), SHARP (sharpening).
As you can see not a huge difference between NORMAL and SHARP.