8-bit or 16-bit Color Depth?
Photoshop works with various color depths (or bit depths). The two most commonly used are:
8 bits per color channel (8-bpc)
16 bits per color channel (16-bpc)
As of the CS2 version, Photoshop also includes a 32-bit mode for use with HDR images. This mode is, however, limited in its scope (see Increasing Dynamic Range Using HDRI Techniques).
8-bpc mode uses 8 bits (1 Byte) to represent each color component of an image. This means that in standard RGB mode, each pixel is stored using 3 × 8 (= 24) bits per channel. Many DSLRs shoot 12- or 14-bit image data per pixel and deliver 16-bit or 48-bit (3 × 16) (per pixel) results ...