Autodesk 12812-051462-9011 User Guide 3 - Page 1478

Exposure control compensates for the limited dynamic range of computer displays, which is typically about two orders of magnitude: The brightest color that appears on a display is about 100 times brighter than the dimmest. The eye, by comparison, can perceive a dynamic range of about 16 orders of magnitude. In other words, the brightest color we can perceive is about 10 million-billion times brighter than the dimmest. Exposure control adjusts colors so they better simulate the eye's great dynamic range, while still fitting within the color range that can be rendered. The exposure controls included with 3ds Max are: ■ Automatic Exposure Control on page 6735 samples the rendered image and builds a histogram to give good color separation across the entire dynamic range of the rendering. It can enhance some lighting effects that would otherwise be too dim to see. ■ Linear Exposure Control on page 6738 samples the rendering and uses the average brightness of the scene to map physical values to RGB values. Linear Exposure Control is best for scenes with a fairly low dynamic range. ■ Logarithmic Exposure Control on page 6740 uses brightness, contrast, and whether the scene is outdoors in daylight to map physical values to RGB values. Logarithmic Exposure Control is better for scenes with a very high dynamic range. ■ mr Photographic Exposure Control on page 6744 gives you camera-like controls including shutter speed, aperture, and film speed, as well as image control over highlights, midtones, and shadows. ■ Pseudo Color Exposure Control on page 6753 is actually a lighting analysis tool. It maps luminances to pseudo colors that show the brightness of the values being converted. IMPORTANT The mental ray renderer on page 6230 supports only the Logarithmic, mr Photographic, and Pseudo Color exposure controls. Left: Linear exposure control maps intensity evenly. Right: Logarithmic exposure control maps most intensities to low and mid tones. Exposure Controls | 6733