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Started Aug 11, 2012 | Discussions thread
dosdan
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Re: Acute.
In reply to vmarks, Aug 21, 2012

vmarks wrote:

I had always assumed the lowest noise would be achieved at the "native" ISO rating of the sensor. Are some canon sensors rated at a higher native ISO, or is this too simplistic?

The Canon sensor has sensor read noise, but the ADC doesn't. So by applying enough analogue gain in the PGA you can reduces the contribution of the ADC noise component. At high analogue gains, i.e. high ISOs, the true low noise nature of the sensor is revealed.

If you look at the read noise at http://www.sensorgen.info which is stated in "input referenced" terms, as if it was additional electrons coming from the sensor, and compare say the read noise values of Pentax K-5 (very low noise ADC with analogue gain), Nikon D7000 (same sensor/ADC, but only digital gain) and an Canon APS-C camera like the 60D or 600D you see how the Canon benefits a lot more for analogue gain.

For more figures and explanations, see:

pentaxforums.com/forums/pentax-k-5/162940-k5-vs-k7-dynamic-range.html#post1689551

pentaxforums.com/forums/pentax-k-5/162940-k5-vs-k7-dynamic-range.html#post1689551

Dan.

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Pentax K20D Pentax K-5 Pentax Q Pentax K-01 Pentax K-3
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