it is a special white balance setting that disables white balance :)

the idea is as following. white balance is essentially 2 multipliers which are used to equalise sensitivity of red and blue channels to the sensitivity of green channel. those multipliers are dependent on the light spectrum (color of light), so they are variable. because they are applied to raw data after conversion to digital, there is no point in using them in camera. application of this coefficients in raw conversion through click-grey method or by copying white balance from a setup shot provides same result.

on the other hand, in camera those coefficients seriously distort histogram display in red and blue channels, preventing good exposure judgement.

you need Nikon Capture NC to load UniWB into the camera.

http://www.pochtar.com/UniWB.zip

NearUniWB is very close to UniWB, but works better with some converters due to some "feature" of those converters :)

Linear custom curve in the archive further prevents any histogram distortions. cleanest (as far as histogram showing actual data distribution) settings are Adobe RGB, Mode II, hue 0, saturation normal, sharpening none.

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Julia