The Importance of Bit Depth
Each digital file you create (capture or scan) is capable of representing a specific number of colors. This capability, usually referred to as the ‘mode’ or ‘color depth’ of the picture, is expressed in terms of the number of ‘bits’. Most photos these days are created in 24-bit mode. This means that each of the three color channels (Red, Green and Blue) is capable of displaying 256 levels of color (or 8 bits per channel). When the three channels are combined, a 24-bit image can contain a staggering 16.7 million separate tones/hues.
This is a vast amount of colors and would be seemingly more than we could ever need, see or print, but many modern cameras and scanners are now capable of capturing up to 16 bits per channel or ‘high-bit’ capture in either Raw or TIFF file formats. This means that each of the three colors can have as many as 65,536 different levels and the image itself, with all three channels combined, a whopping 281,474,976 million colors (last time I counted!). But why would we need to capture so many colors ?
More Colors Equals Better Quality
Most readers would already have a vague feeling that a high-bit file (16 bits per channel) is ‘better’ than a low-bit (8 bits per channel) alternative, but understanding why is critical for ensuring the best quality in your own work. But the image quality also depends on the resolution or number of pixels, if the image is low in quality or resolution, people tend to apply vector conversion to increase the quality of the image. There are also some photo editing methods which help to improve the quality of the images for example clipping path, photo retouching, photo manipulation, and old photo restoration etc.
Comparing Bit Depth:
The higher the bit depth of an image the more levels of tone and number of colors it can display.
Here are the main advantages in a nutshell:
- Capturing images in high-bit mode provides a larger number of colors for your camera or scanner to construct your image. This in turn leads to better color and tone in the digital version of the continuous tone original.
- Global editing and enhancement changes made to a high-bit file will always yield a better quality result than when the same changes are applied to a low-bit image.
- Major enhancement of the shadow and highlight areas in a high-bit image is less likely to produce posturized tones than if the same actions were applied to a low-bit version.
- More gradual changes and subtle variations are possible when adjusting the tones of a high-bit photograph, using tools like Levels, than is possible with low-bit images.