[Leica] Re: Photokina _ The lens on Tom's RD1

[jcb at visualimpressions.com (JCB)]

At 12:57 AM 10/5/2004, Frank Dernie wrote:

>All the serious cameras with large chips, including the RD1, need a shutter.


Sorry, not true. The "shutter" on all digital sensors is a pulse to the 
sensor substrate. It opens and closes the photo transistor switches to 
allow the collection of electrons by the holding caps, followed immediately 
by the readout pulses, rows, then columns, sending the individual pixels 
through the A/D converter.

Digital cameras, even P&S, don't use video sensors. All normal camera 
sensors, even the tiny sensors, have a special "movie" mode where every 
third or fifth row of the sensor is scanned rather than every row in order 
to scan it fast, and that decimated image is what is displayed on the LCD 
while you look and move the camera around. Likewise, this mode is used to 
capture short movies, which is why it is not really smooth and the 
resolution is low.

JB