Finally, a D300 Near UniWB JPEG

Started Apr 3, 2008 | Discussions thread
GaborSch Veteran Member • Posts: 7,203
Filter for DR

petroag wrote:

When using uniwb the photo does appear green. I would think this is
a result of the bayer filter pattern. 50% more green so you see
green in the exposure

No, it has nothing to do with that. You don't see raw pixels (except with Rawnalyze). If a white object appears greenish with UniWB, that indicates, that the captured light contains more green than other wavelengths. This has nothing to do with the number of pixels, but with

1. the ilumination,

2. the microfilter over the pixel sites.

Now if I wanted to expose the red and blue
channels to the right without blowing out the green channel, wouldn't
I want to use a green filter such as CC30M? I then could get all
channels exposed to the right more efficiently and then correct for
WB in post processing.

CC30M is a magenta filter. That would be the right one, though the 30 may be too strong. If you analyze shots with Rawnalyze, you can see, how much stronger the green comes in different settings.

I already ordered a B+W CC20M, and it turned out, that it has been taken out of production. Though I had some concerns anyway: these filters are not meant for digital photography, they are not coated like really good UV or polar filters are. Digital is much more sensitive to internal reflections and stray light than film.

Someone had another idea, useful only indoor: put a "filter" (it can be even cellophane) at the front of your light source. But that is not necessarily magenta, it depends on the light source; incandescent is typically very warm, so you would want to filter out the red. A cyan-like "filter" would be useful in such case.

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