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<blockquote data-quote="aroy" data-source="post: 216822" data-attributes="member: 16090">What I meant is, that you set the camera ISO at 100 and the other exposure parameters for ISO 50 - over expose by a stop. You thus get lower shutter speed and during processing just get rid of the left most bit data.From what I know of image sensors, the native ISO is the one where the full well capacity is achieved at the stated exposure. The camera manufacturers in general leave a margin for over exposure (1/2 stop or so), which is why you can recover a bit of highlight. Higher ISO is achieved by analog amplification prior to A-D conversion, but the noise remains the same with respect to the signal, hence higher noise at higher ISO.My original question was that, if the signal is amplified (along with the noise) by the camera, is the resultant signal and noise as much as you would get by just shifting the histogram by those many bits, or is it better. In case the noise if same or at the most marginally better, in my opinion it would be easier to underexpose the image by using the native ISO and shifting the histogram in post processing.</blockquote>

[QUOTE="aroy, post: 216822, member: 16090"] What I meant is, that you set the camera ISO at 100 and the other exposure parameters for ISO 50 - over expose by a stop. You thus get lower shutter speed and during processing just get rid of the left most bit data. From what I know of image sensors, the native ISO is the one where the full well capacity is achieved at the stated exposure. The camera manufacturers in general leave a margin for over exposure (1/2 stop or so), which is why you can recover a bit of highlight. Higher ISO is achieved by analog amplification prior to A-D conversion, but the noise remains the same with respect to the signal, hence higher noise at higher ISO. My original question was that, if the signal is amplified (along with the noise) by the camera, is the resultant signal and noise as much as you would get by just shifting the histogram by those many bits, or is it better. In case the noise if same or at the most marginally better, in my opinion it would be easier to underexpose the image by using the native ISO and shifting the histogram in post processing. [/QUOTE]

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