Photoshop® CS3 Restoration and Retouching Bible

Chapter 3. Understanding Raw and High-Bit Files

IN THIS CHAPTER

• Understanding Raw

• Converting Raw files in Photoshop CS3

• Working with 16-bit files

• Using Adobe Camera Raw to edit 16-bit scans

In the world of digital imaging, not all files are created the same. Some files have more information Lhan others. This extra information can be handy when you're called upon to do "heavy lifting" — to make extreme tonal adjustments or do heavy retouching. We call these files high-bit because they have more bits of information per pixel than a regular image file. The most common way to get a high-bit file these days is by shooting in the Raw format in your digital camera and then using Photoshop CS3 to convert that Raw data into a high-bit file. You also can get high-bit files from most print and film scanners. In this chapter, we look at all these issues and more so you'll know when to use them and be prepared to take advantage of them when the need presents itself.

What Is Raw?

When I point my DSLR at a scene and click the shutter, the camera's chip cap-lures a huge amount of information. If I have the camera set to capture JPG files, the camera's onboard processor processes all that information into a JPG file. The processor looks at all the settings I have dialed into my camera — sharpness, white balance, color space, contrast, and so on. Then it applies all these settings and creates the JPG Pile from a small sliver of the data that the chip recorded. The rest of the information — most of what ...