ProPhoto RGB color space

The ProPhoto RGB color space, also known as ROMM RGB (Reference Output Medium Metric), is an output referred <a href="/facts/RGB_color_space/00Q0tTS5">RGB color space</a> developed by <a href="/facts/Kodak/zMnK74Cp">Kodak</a>. It offers an especially large <a href="/facts/Gamut/bRQc2fCr">gamut</a> designed for use with <a href="/facts/Photographic/ezLPT43M">photographic</a> output in mind. The ProPhoto RGB color space encompasses over 90% of possible surface colors in the <a href="/facts/International_Commission_on_Illumination/46q6W1zk">CIE</a> <a href="/facts/Lab_color_space/jxx4j975">L*a*b* color space</a>, and 100% of likely occurring real-world <a href="/facts/Munsell_color_system/SanJo9rD">surface colors</a> documented by Michael Pointer in 1980, making ProPhoto even larger than the <a href="/facts/Wide-gamut_RGB_color_space/FwX3lYtb">Wide-gamut RGB color space</a>. The ProPhoto RGB primaries were also chosen in order to minimize hue rotations associated with non-linear tone scale operations. One of the downsides to this color space is that approximately 13% of the representable colors are <a href="/facts/Imaginary_color/Jm6jPWK0">imaginary colors</a> that do not exist and are not visible colors.
When working in <a href="/facts/Color_space/zFvEyfHv">color spaces</a> with such a large gamut, it is recommended to work in 16-bit color depth to avoid <a href="/facts/Posterization/SEdYoKRj">posterization</a> effects. This will occur more frequently in 8-bit modes as the gradient steps are much larger.
There are two corresponding scene space color encodings known as RIMM RGB (Reference Input Medium Metric) intended to encode standard dynamic range scene space images, and ERIMM RGB intended to encode extended dynamic-range scene space images.

ProPhoto RGB color space open-in-new

ProPhoto RGB color space