[outsider]

Question: Do the "lo" ISO settings on nikon cameras improve dynamic range"? Haven't been able to find any scientific tests to prove or disprove and have heard varying opinions from many people. Someone claimed that DXOMark did tests that showed dynamic range improved with the lo settings in the D300, but I can't find that article. I know these settings aren't a true iso, but a sort of digital mimic where the data is reprocessed and spit back onto the card. Personally, I feel I see an improvement in dynamic range beyond iso 200, when using the lo settings and certainly lower noise. But I'm really not sure why nikon didn't just give us a true iso 125 other than maybe there is added benefit with these lo settings we aren't aware of. I seem to be able to pull out detail in underexposed photos in my D300 more easily in the lo settings. There doesn't seem to be any visible degredation of the photo when using lo3 or lo6 or whatever. What are your thoughts about the iso settings?

[Adam]

Question: Do the "lo" ISO settings on nikon cameras improve dynamic range"? Haven't been able to find any scientific tests to prove or disprove and have heard varying opinions from many people. Someone claimed that DXOMark did tests that showed dynamic range improved with the lo settings in the D300, but I can't find that article. I know these settings aren't a true iso, but a sort of digital mimic where the data is reprocessed and spit back onto the card. Personally, I feel I see an improvement in dynamic range beyond iso 200, when using the lo settings and certainly lower noise. But I'm really not sure why nikon didn't just give us a true iso 125 other than maybe there is added benefit with these lo settings we aren't aware of. I seem to be able to pull out detail in underexposed photos in my D300 more easily in the lo settings. There doesn't seem to be any visible degredation of the photo when using lo3 or lo6 or whatever. What are your thoughts about the iso settings?

I think that the naming convention itself suggests that there's no DR benefit below the minimum ISO, just like there's no benefit above the max non-expanded ISO, etc.

[Aegon]

I agree that DR is probably not improved, and may even be diminished ever so slightly. But ISO Lo lets you get a faster effective shutter speed for flash sync (the max shutter speed for flash may be 1/200 or thereabouts, and that won't change at ISO 100 or ISO Lo, but at ISO Lo the contribution of the flash will be proportionally higher compared to ambient, which may matter in some cases).