In the second part of this series we left the developed photos in Camera RAW using the ProPhoto RGB space to ensure that there is one and only one conversion color space . Let us see how we proceed when we open the image in Photoshop .

Once the RAW is revealed (it should make all possible adjustments and color levels on the RAW and not in Photoshop ) can generate a 16-bit TIF file or open it in Photoshop. The choice is up to everyone's taste, I, by the way I work, I open them directly and did not generate any files until you finish editing the image.

We will do all the editing that is necessary and will keep a TIF editing layers (always work with layers so that the work is reversible), in 16 bits and ProPhotoRGB space. Thus, if you later want to change something, we still have the maximum amount of information. 16-bit and wider color space. Unless we need to modify some of the development, we work only with the TIF quietly.

Then we can draw two JPG files, one to send to print in AdobeRGB and one for the web in sRGB . In both cases, part of the original TIF for a single conversion. In Photoshop we go to Edit -> Convert to Profile ... (CAUTION!, If we get confused with Assign Profile ... we will have a disastrous colors and we'll go crazy trying to figure out why you would not be the first.) In the window that appears choose the destination space we want and the conversion mode to choose from four:

1. Perceptual. Maintains visual relationship between colors, but their values may change. If there are many colors out of range is the right choice.
2. Saturation. Create vivid colors regardless of accuracy. For photography forget it, only useful for graphics where exact color does not matter.
3. Relative Colorimetric. The colors are out of range of approaches as close as possible, and the rest tries to keep the visual. It is usually the best option.
4. Absolute Colorimetric. The colors within the range does not change, and those who are out of range of the nearest approaching, so clipping occurs at the ends piling up all out of gamut colors in a single value.

The normal thing is to use the relative colorimetric, and only images with many colors appeal to perceptual extremes. In the program's help for more details on the four methods.

After converting the color space converted to 8 bit image and save the JPG. Thus we worked all the time that it has been possible with as much information as possible, ie 16 bit and ProPhoto RGB space. We also keep a copy in TIF file with all this information and we use it to generate the JPG only as a last step needed to upload to the web or send it to print.

Some laboratories also accept TIF, but it would be suicidal to send it in ProPhoto RGB not sure before going to handle it well. If working in AdobeRGB or sRGB (as will happen in 99% of cases) the quality difference between sending a 16-bit TIF or JPG of 8 with the minimum compression is negligible, and JPG are much more manageable.

Other articles in this series:

1. "AdobeRGB or sRGB? (I)
2. "AdobeRGB or sRGB? (II)
3. "AdobeRGB or sRGB? (YIII) (This post)