Autodesk 12812-051462-9011 User Guide 3 - Page 2082

Exposure group Black Point When this option is turned on, you can set the luminance value that you would like to be treated as the darkest color, or "black". The value can be set as a logarithm (Log) or as a linear value (Linear). All values below this value will be clamped to black. When this option is turned off, the lowest possible value is used as the Black Point. Measured Min/Max Displays the actual minimum and maximum luminance values in the image, expressed as both the logarithmic and linear values. Using these values for the Black Point and White Point will result in the image's full luminance range being used. However, the histogram might show that the majority of the luminance levels fall into a much smaller range. White Point Sets the luminance value that you would like to be considered the brightest color, or "white", either as a logarithm (Log) or linear value (Linear). All luminance values in the image that are above this value will be clamped to white. White pixel values inside HDR files can be much larger than a Linear value of 1. The image's extended luminance range is used only when the White Point's Linear value is set above 1.0. In other words, setting White Point at or below a Linear value of 1.0 will not use any of the HDR image's special luminance properties, and will give results similar to other bitmap formats such as TIF and JPG. Log Sets the Black Point or White Point as a logarithmic value ranging from -128 to 127. Changing this value changes the Linear parameter to the corresponding value. Linear Sets the Black Point or White Point as a linear value ranging from 0 to over 1 trillion. Changing this value changes the Log parameter to the corresponding value. Preview window Displays the selected HDR image. Internal Storage group Real Pixels (32 bpp) Compresses the luminance selections into a color space with 32 bits per pixel. Premultiplied Alpha and Motion Blur do not work with this option. Def Exposure When on, the image will load as is without applying any changes to the colors. When off, you can use the parameters in the Exposure group to remap colors. Available only with the Real Pixels option. HDRI Files | 7337