kim_hdr: X100 is very beautiful cam ! the XS1 is very ugly !
thx1138, what determines exposure is not sensor size, but the amount of light per area
if you compare an F2.8 DSLR lens for a 35mm sensor and a F2.8 lens of a compact, they shutter speed will be the same for the same F-number, in the same circumstances
what will be different is the amount of light that hits the two different sensors; it is obviously bigger for the DSLR, that is hy it gives a better picture quality
what will be the same, is the amount of light per unit, so, for 1 square mm, the amount of light will be the same for both sensors, but the DSLR has a bigger sensor surface, hence is the better quality, but the exposure time is the same
try it yourself with cameras that have different sensor sizes