03-20-2011, 11:23 AM
I do not think Nikon actually has disclosed in what ADL is (read: how it is achieved).
As far as I understand it, it does not "alter" RAW data as such, but it does change exposure. Depending on the metering, it underexposes a bit or a bit more, to preserve highlights. In processing (either in-camera when shooting JPEG or in-computer when using a Nikon RAW convertor) a different tonal curve is applied to lift the shadows. Apparently, also some masking and processing is applied to increase local contrast, which can result in HDR like halos around bright or dark subjects.
In RAW convertors which do not do anything with the "ADL" setting, you will then just notice a slight difference in exposure, even if the EXIF settings say the exposure time is the same.
So... the RAW data is different due to a different exposure, but the RAW data collected from the sensor is not changed before being saved to NEF.
As far as I understand it, it does not "alter" RAW data as such, but it does change exposure. Depending on the metering, it underexposes a bit or a bit more, to preserve highlights. In processing (either in-camera when shooting JPEG or in-computer when using a Nikon RAW convertor) a different tonal curve is applied to lift the shadows. Apparently, also some masking and processing is applied to increase local contrast, which can result in HDR like halos around bright or dark subjects.
In RAW convertors which do not do anything with the "ADL" setting, you will then just notice a slight difference in exposure, even if the EXIF settings say the exposure time is the same.
So... the RAW data is different due to a different exposure, but the RAW data collected from the sensor is not changed before being saved to NEF.