JamesBeach wrote:
There\'s some confusion about sensor signal gain. Some people believe that there is but one \"native\" sensitivity for a sensor and anything but that is digital manipulation of the data. But, as far as I know, changing the ISO in camera changes the way the sensor interprets the analog signal into digital data. That is, the gain is performed on the analog signal, not the digital one. Another point I believe to be the case is that the \"expanded ISO\" gain settings (usually below 100 and above 6400, but it varies) as well as some of the ISO settings in between major stops are performed digitally. I don\'t believe there to be a \"native\" level of gain.
I\'m open to being corrected on either of these issues, of course.
In any case, the best ISO to use for a given image is the lowest one possible that delivers the desired exposure, like anything else. Assuming you don\'t appreciate the qualities of a grainy high ISO image. If you do, then by all means go higher.
On most cameras intermediate (between stop) ISOs are not implemented by adjusting the gain but by pushing the exposure. In addition the highest ISO setting is often pushed and not by gain.Which stops are pushed are camera dependent.
JamesBeach wrote:
There\'s some confusion about sensor signal gain. Some people believe that there is but one \"native\" sensitivity for a sensor and anything but that is digital manipulation of the data. But, as far as I know, changing the ISO in camera changes the way the sensor interprets the analog signal into digital data. That is, the gain is performed on the analog signal, not the digital one. Another point I believe to be the case is that the \"expanded ISO\" gain settings (usually below 100 and above 6400, but it varies) as well as some of the ISO settings in between major stops are performed digitally. I don\'t believe there to be a \"native\" level of gain.
I\'m open to being corrected on either of these issues, of course.
In any case, the best ISO to use for a given image is the lowest one possible that delivers the desired exposure, like anything else. Assuming you don\'t appreciate the qualities of a grainy high ISO image. If you do, then by all means go higher.
On most cameras intermediate (between stop) ISOs are not implemented by adjusting the gain but by pushing the exposure. In addition the highest ISO setting is often pushed and not by gain.
Nov 07, 2011 at 09:16 AM
Previous versions of GeneO's message #10064545 « Canon's native ISO »
