want to buy a digital camera, but i want one that works best in the dark (night mode)?

Answer 1

You will need a DSLR or a high-end digicam (like the Canon G9) that will support an off-camera flash. The built-in flash is simply too weak to be of much use at night. Even a very powerful off-camera flash will be a small improvement. See the Inverse Square Law (it explains how light intensity decreases the farther it gets from its source).

Correct exposure, under any lighting conditions, is a product of f-stop, ISO, shutter speed and the available light. Digital cameras don't have "magical powers" that allow them to defy the rules of correct exposure.

To successfully shoot without flash in low light you need a "fast'' lens - f1.4 or 1.8 and an ISO of 400 or 800 or higher (depending on the ambient light). If your lens is wide open at f2.8 then you may need an ISO of 1600 or higher. Look at these examples taken from my FotoSharp (fotosharp.com) Day & Night Exposure Guide:

Home interiors - bright light

ISO 200

f1.4 @ 1/60 second
f2 @ 1/30 second
f2.8 @ 1/15 second
f4 @ 1/8 second

ISO 400

f1.4 @ 1/125 second
f2 @ 1/60 second
f2.8 @ 1/30 second
f4 @ 1/15 second

ISO 800

f1.4 @ 1/250 second
f2 @ 1/125 second
f2.8 @ 1/60 second
f4 @ 1/30 second

How about home interiors, average light?

ISO 200

f1.4 @ 1/30 second
f2 @ 1/15 second
f2.8 @ 1/8 second
f4 @ 1/4 second

ISO 400

f1.4 @ 1/60 second
f2 @ 1/30 second
f2.8 @ 1/15 second
f4 @ 1/8 second

ISO 800

f1.4 @ 1/125 second
f2 @ 1/60 second
f2.8 @ 1/30 second
f4 @ 1/15 second

How about a dimly lit night club?

ISO 800

f1.4 @ 1/15 second
f2 @ 1/8 second.
f2.8 @ 1/4 second

ISO 1600

f1.4 @ 1/30 second
f2 @ 1/15 second
f2.8 @ 1/8 second

ISO 3200

f1.4 @ 1/60 second
f2 @ 1/30 second
f2.8 @ 1/15 second

As you can easily see, available light (non-flash) photography is possible but not easy. Most all digicams are going to use the flash in their "Night Scene" setting and while your subjects closest to the camera may be properly exposed the background will be very dark (back to the Inverse Square Law). If you are too close to your subjects they may even be over-exposed while the background goes dark.