03-20-2011, 09:49 AM
I am somewhat confused about the function of the ADL (Active D-Lighting) in Nikon cameras. My question is: When shooting in RAW format and the ADL is on, does ADL affect the RAW image data stored in the camera?
In various places it has been claimed that the ADL of Nikon can increase the dynamical range of the camera. If this is true, then it implies that the ADL does affect the RAW image data otherwise I would not understand why the danuamical range of the camera can be increased unless the above statement implicitly means that "the ADL of Nikon can increase the dynamical range of the camera when shooting in jpg".
To test the ADL function I shoot the same scene twice: both in raw format, one with ADL off (image1, I call it) the other with ADL on (image2). Then I uploaded the two raw files to my computer, and used NX2 to open them. In NX2, I turned off the ADL of image2, then I got a new image image2a. I found that image2a is clearly different from image1: they look different (with different exposure), and the two exposure histograms are also distinctly different. I think this indicates that the ADL cannot be "turned off" after shooting.
I would think that my test has confirmed that the ADL affetcs the raw data. That is, the raw data have been changed by ADL before they are written to the card.
I don't know if my understanding is correct so I post it here for some comments. I cannot find an "official" interpretation about what ADL has done to the RAW image data.
Frank
In various places it has been claimed that the ADL of Nikon can increase the dynamical range of the camera. If this is true, then it implies that the ADL does affect the RAW image data otherwise I would not understand why the danuamical range of the camera can be increased unless the above statement implicitly means that "the ADL of Nikon can increase the dynamical range of the camera when shooting in jpg".
To test the ADL function I shoot the same scene twice: both in raw format, one with ADL off (image1, I call it) the other with ADL on (image2). Then I uploaded the two raw files to my computer, and used NX2 to open them. In NX2, I turned off the ADL of image2, then I got a new image image2a. I found that image2a is clearly different from image1: they look different (with different exposure), and the two exposure histograms are also distinctly different. I think this indicates that the ADL cannot be "turned off" after shooting.
I would think that my test has confirmed that the ADL affetcs the raw data. That is, the raw data have been changed by ADL before they are written to the card.
I don't know if my understanding is correct so I post it here for some comments. I cannot find an "official" interpretation about what ADL has done to the RAW image data.
Frank