Contrast?

There are two distinctly different types of contrast that can be adjusted in an image for optimal reproduction. Differentiate between these two types of contrast and explain how and where these adjustments affect the image. What would be the proper Photoshop controls to use for tonal adjustment? Explain how they work.

Overall contrast relates to the image as a whole in analyzing the brightest whites composed of the smallest halftone dots and the darkest blacks composed of the largest halftone dots. The key is working toward accurate highlight and shadow density and the correct halftone dots dimension.

Contrast adjustment may very from image to image. It focuses on the mid tones keeping the highlight with the smallest dots and shadow with the largest. Adjustments are made by shifting the tone of the 50% dots.

A great tool in Photoshop for quick tonal adjustment is the brightness/contrast tool. It allows you to easily make quick adjustments to the contrast which can quickly sharpen the image as well as adjustments to the brightness which directly controls the over all level of the image. For greater control over adjustments directly to the shadows, highlights, or midtone the Shadows/Highlights, levels, or curves tools are ideal.


Resources:
AIO Lecture