Q2 - ISO 50

[tnturnerx1]

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I'm confused what 'native' ISO means. I've read in some review that the ISO 50 setting on Q2 is NOT 'native', but 'pulled' (whatever that means). I also read  in another review that the ISO Auto lowest setting on Q2 is ISO 100 which (to the author of the review) 'proves' that ISO 50 is not 'native'.  I've seen specs on other cameras (that I didn't buy) that started native ISO at ISO 200 but 'pulled' to ISO 100.  When ISO is 'pulled' (someone please explain) is the ISO somehow simulated, not real?  If ISO 50 is 'native' would shooting at ISO 50 produce better, sharper images than shooting at ISO 100?  As an example, shooting ISO 100 instead of ISO 200.  Of course, shooting ISO 50 only when appropriate for the exposure. Thoughts? 

[nariza7]

im curious about this too. I just wonder if the dynamic range suffers at ISO 50 or if its best at 100 ISO or something

[marchyman]

Educated guess: Native ISO is the ISO where the values pulled from the sensor are neither amplified or attenuated.  Both amplification and attenuation will have some effect on the image.   The effect may not be noticeable.

[cnj]

To answer the other question, "pulled" and "pushed" come from film developing. "pushing" a film means developing the film such that it reacts as a more sensitive (higher ISO) film. "pulling" is developing for a shorter time, or specifically such that it reacts like a less-sensitive film (darker, lower ISO).

Think of exposure and developing as both happening inside of the camera in the digital world.

Digital imaging systems have a base ISO (read the same as native ISO above), which can have a hardware gain applied to amplify the exposure signal to match higher ISO equivalences. Outside of the hardware range, the camera can generate images at other equivalencies by effectively faking it in the development stage of its imaging pipeline. "Extended ISO" settings generally means pushing/pulling in this development stage, and some cameras hide them in a special menu setting or otherwise highlight that they're special in some way.