Hi folks
Can someone PLEASE explain the difference between "Perceptual" and "Relative" in the Rendering Intent bit of Lightrooms Colour Management?
Differing techniques for handling out of gamut colors (colors in the working space that are out of gamut for the printer space).
Each device has a range of colors that it can reproduce, and that range is described within the device’s color space. Colors that are available in one color space but not available in another color space are called out-of-gamut colors. Colors in the original (source) color space need to be mapped to colors that exist within the gamut of the new (destination) color space. There are two basic techniques for mapping out-of-gamut colors. One technique is to take all the colors that are out-of-gamut and map them to the closest colors that are within color gamut of the destination. We call this technique gamut clipping. The second technique is to compress the range of color into the gamut of the destination. It is important to note that when using this method, some colors that were perfectly matched between the two devices will actually change. We call this method gamut compression.
The ICC system provides different methods of gamut mapping and calls these rendering intents. When you perform ICC color transformations within an application, you will need to choose a rendering intent. The rendering intents were created for different situations. The names of the renderings are colorimetric, saturation, and perceptual.
The colorimetric method is a form of gamut clipping. The saturation intent is also a form of gamut clipping, but attempts to preserve the saturation of colors over lightness. The perceptual method is a form of gamut compression. When using the perceptual method, visual detail and luminance are preserved over hue and saturation.
The best rendering intent is the one you visually prefer (when soft proofing). Profiles don’t know anything about images. So you need to view the two options (usually Perceptual or RelCol), see which you prefer visually then select that. Since there is no soft proofing in LR, that means something like Photoshop.
