I mounted a 135mm lens on my D4. That’s the longest lens I can use an still get the whole target square in the image. I took a picture of a random magenta square to see how tight the raw histograms would be: The Rawdigger histograms aren’t super tight, but that’s about all I can… [Read More]

I’ve been working on ways to reduce the number of iterations required to calibrate a camera using UniWB, while requiring the use of only two programs by a user of this technique: Photoshop and Rawdigger. I first wrote a little Matlab program to generate a 10×10 grid of samples with a constant green value of… [Read More]

In the preceding post, the histogram for the D4 had more spread to it than the one for the D800E. It’s not the camera. It’s the lens. The D800E looked at the monitor through a 200mm lens, and the D4 through a 100mm one. It turns out that, with my 30in NEC PA301W monitor, that… [Read More]

In doing research on in-camera histograms, I have found repeated assertions that the luminance histogram is the same as the green channel histogram, color science to the contrary (the only RGB color space in which colorimetric luminance is the same as the green channel would have to have three identical primaries, all of them the… [Read More]

I have a D3x modified by LifePixel with the so-called “Deep IR” filter. I attempted to get the in-camera histogram to look like the real raw histogram. I achieved only partial success. With the camera now so IR-sensitive in all three channels (the red, green, and blue filters that form the Bayer pattern on the… [Read More]