Myths in photography and optics

• Human eye is more sensitive to chromatic noise than to luminosity noise.
• LAB color space separates “the brightness part” and “the color part” of an image.
• Digital has small dynamic range and to handle high dynamic range subject, one must stack several shots.
  It is not only that digital has high dynamic range; in fact, “dynamic range” (at a particular ISO number) is not even a number but is a curve (or two) which describe how dynamic range depends on the level of resolution you want to keep. These curves also describe the “color” of noise (“what kinds of patterns are made by the noise”). We provide 6 numbers which describe these curves. So: if one is ready to sacrifice some details, the range may be VERY high (19 steps or somesuch)!
• Magnification of a loupe is 250/f (it turns out that the newer WikiPedia already has a correct formula).