Setting ISO on D90

[satishpatnaikg]

hi,

how do we set the ISO between 100 to 200 for Nikon D90.

I checked it but after 200, it is moving towards Lo, I am not sure what is the value of it.

I want to set the ISO less than 200 as needed.

thank you

[Nicole]

Below ISO 200 is Lo 1, Lo 2, and Lo 3. They aren't actual ISO values per se... well, they're done by the camera processing things...

In any case, the approximates are:
Lo 1.0 = ISO 100
Lo 0.3 = ISO 130
Lo 0.7 = ISO 160

[satishpatnaikg]

thank you very much.

[Almond.Butterscotch]

Originally Posted by Nicole

They aren't actual ISO values per se... well, they're done by the camera processing things...

wait- how's that?

[Nicole]

Well, the native ISO is 200-3200 on the D90. The Hi and Lo settings are "extended ISO" which makes them something other than the native ISO, so they have to be achieved somehow...

Re: Lucas123 is correct....Amplification is misleading....: Nikon D90 - D40 / D5000 Forum: Digital Photography Review
Noise, Dynamic Range and Bit Depth in Digital SLRs -- page 2 (toward the bottom of the page)

At least that's the understanding of it I have from reading about it.

[Almond.Butterscotch]

well dagnabbit. So the D3S only really does 200 - 12,800.

[OsmosisStudios]

Originally Posted by Almond.Butterscotch

well dagnabbit. So the D3S only really does 200 - 12,800.

Natively. It'll do "100" by pull processing and up to 102k by push processing

All ISO in a digital camera is is amplification of a signal. So if the sensor natively does 200, getting to 100 is simply a matter of halving the amplitude of a signal. Getting above the native 12 800 is simply a case of multiplying by 2 for each stop.

[Almond.Butterscotch]

well i get that, but over-amplification of a signal- any signal- always has undesired artifacts and noise. It's left me wondering what ISO100 looks like now (I never bothered going down from 200 in the couple of weeks I was using a borrowed D90)

[OsmosisStudios]

It has about the same noise as 200 (Ie none) but has a slightly smaller dynamic range. I don't see the point unless you absolutely need that extra stop.

[Almond.Butterscotch]

I was wondering mostly because one of my flickr contacts shoots all his landscapes at ISO100. I always thought it was for the extra couple seconds- on top of what he'd get from the small apertures (f/8 or thereabouts) and his Big Stopper (10 stop ND)- but I was wondering if noise might've been the issue here.

Decidedly not.