Short ISO test with Canon PowerShot S90IS. Where I write "no lights" I mean I switch off the neon lights in the room. White balance is on auto all the time.
The aperture is 4. The f2 it's only for wide side of the lens - 6 mm, if you zoom as far as 6.8 the aperture change to 2.2 and up if you continue to zoom. It reach f4.9 around 19 mm. And by the way 8 it is last f stop. Shutter speed 15 - 1/1600 sec (total range - varies by shooting mode)and no Bulb possibility.