tailieunhanh - Photoshop Lab Color- P6

Photoshop Lab Color- P6: LAB has a reputation for enormous power, yet virtually all reference materials that advocate its use illustrate its capabilities with a single class of image. This chapter introduces the basic LAB correction method and explains why it is so extraordinarily effective. if you happen to have a picture of a canyon. | Summing Up LAB and the Workflow 151 Color instead of Normal. That restores the original detail while retaining the color created by the curves. Step Three Now we re in LAB. You already know the drill here. There s little need to discuss Step Four which is going to be a cleanup operation to make any final adjustments. Two possible variations depend upon whether Step Four is a CMYK or RGB step. If it s CMYK then during Step Three I ll consider where the sharpening if any should be done. Generally if the image is dominated by a single color I ll go the CMYK route if not the L. And if Step Four is an RGB step then I sharpen the L for sure. Also if Step Four is CMYK and the shadow is currently too light I won t fix it in LAB because it s so much easier to adjust in the black channel of CMYK. If Step Four is RGB then I don t much care where the shadow gets adjusted. By the Numbers and by the Instinct Before closing out the chapter and with it the first half of the book we should look at three specialized maneuvers. Two as promised earlier are for those people who are under such pressure to get images out quickly that they need to adopt an all-LAB workflow never mind that they could get better pictures if they had more time. The other involves a duplicate layer like the theoretical one we just constructed in RGB to prevent the clouds from getting too blue. A lot of color work depends on doing things by the numbers starting with white point and black point. The last example we discussed a curve that was designed to make the edges of a hypothetical cloud less blue was also a by the numbers correction. Experienced folk would understand the assignment to be make the blue parts of the cloud more neutral. They would know that in RGB neutral colors occur when all three channels have equal numbers. They would also know that an overly blue cloud means that the red channel is too dark or the blue channel too light or both. So they would try to equalize the two values or get as .