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<blockquote data-quote="WayneF" data-source="post: 215872" data-attributes="member: 12496">The LO ISO method does not meet ISO standards,&nbsp; in this way:The sensor has only one designed ISO value, that is to say, the sensor can only do whatever it can do.Higher&nbsp; ISO is simply a math operation afterwards.&nbsp;&nbsp; ISO 200 multiplies all pixel data by&nbsp; 2, and ISO 400 by 4. etc.&nbsp; This shifts all data&nbsp; right in the histogram.&nbsp; including the noise near zero has been shifted higher too.&nbsp; This&nbsp; simulates more exposure (but the sensor only has one exposure possibility).LO ISO simply divides,&nbsp; and shifts data&nbsp; left in the histogram.&nbsp;&nbsp; That simulates less sensitivity (does not change what is captured, but simply shows it differently - like you would do in a later editor). This left shift (LO 1.0) also leaves&nbsp; the top half of sensor range blank, unused, which is a stop less dynamic&nbsp; range.&nbsp; The final histogram you see is not blank, because the scale is&nbsp; changed so what you see appears to be a full exposure, but it is not, in&nbsp; that the top half of the sensor dynamic range was not used.&nbsp; It is basically a contrast reduction.A ND filter will change what the sensor actually captures, and does not suffer the same loss of dynamic range.</blockquote>

[QUOTE="WayneF, post: 215872, member: 12496"] The LO ISO method does not meet ISO standards, in this way: The sensor has only one designed ISO value, that is to say, the sensor can only do whatever it can do. Higher ISO is simply a math operation afterwards. ISO 200 multiplies all pixel data by 2, and ISO 400 by 4. etc. This shifts all data right in the histogram. including the noise near zero has been shifted higher too. This simulates more exposure (but the sensor only has one exposure possibility). LO ISO simply divides, and shifts data left in the histogram. That simulates less sensitivity (does not change what is captured, but simply shows it differently - like you would do in a later editor). This left shift (LO 1.0) also leaves the top half of sensor range blank, unused, which is a stop less dynamic range. The final histogram you see is not blank, because the scale is changed so what you see appears to be a full exposure, but it is not, in that the top half of the sensor dynamic range was not used. It is basically a contrast reduction. A ND filter will change what the sensor actually captures, and does not suffer the same loss of dynamic range. [/QUOTE]

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