My guess would be the sensor "base" speed is the speed At which no extra light ( slower sensor speed ) will improve The image quality any signifigant amount. No sense in Going slower if it doesn't improve anything. jco
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of William Robb Sent: Tuesday, October 31, 2006 9:54 PM To: Pentax-Discuss Mail List Subject: Re: Designing a Sensor ----- Original Message ----- From: "Joseph Tainter" Subject: Designing a Sensor > How does the base ISO in a sensor come about? Is it an intentional > design component? I expect they do it the same way as with film. I don't recall the formula now, but there is an iso standard that is pretty repeatable by the common man. > > What I am getting at is, could the 10 mp sensor in the K10D have been > designed to have a base ISO of 200? 400? Anything? Perhaps, but the ISO standard should insist on a certain amount of signal from a certain amount of light. With film the speed is determined by measuring one stop over film base+fog and applying the formula I no longer remember. I expect with digital, signal minus noise is the number applied to the iso speed formula. William Robb -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
