"Nenad Djurdjevic" <[EMAIL PROTECTED]> wrote: >I think this has been asked before but I don't recall any concensus or >convincing explanations: > >Why do DSLRs need mechanical shutters when video cameras and "point and >shoot" digitals don't (or do they? - my Optio 43WR specs say the shutter >goes from 4sec to 1/2000sec).
The small sensors used for digicams output their data using a technique called Interline Transfer, whereas larger sensors use a technique called Frame Transfer. Interline Transfer allows shuttering to be performed electronically, but it has higher noise levels and higher chip complexity. This second factor is especially important when manufacturing the already-very-expensive sensors used on DSLR's because the cost of the sensor increases roughly geometrically with respect to size. So in small sensors the extra complexity doesn't cost much and is paid for by not needing to put a shutter in the camera. With large sensors the cost of a shutter is less than the expense of using an interline transfer sensor (and you get better sensitivity and noise performance, too). At least that's how I understand it...
