The Wiki definition of contrast is “Contrast is the difference in luminance or colour that makes an object (or its representation in an image or display) distinguishable. In visual perception of the real world, contrast is determined by the difference in the color and brightness of the object and other objects within the same field of view.”. Adobe defines it through the use of the tools as “The difference in brightness between light and dark areas of an image. Contrast determines the number of shades in the image….A low-contrast image (left) retains detail but tends to lack dimension and looks soft. An image with normal contrast (center) retains detail and dimension, and looks crisp. A high-contrast image (right) loses detail especially in areas with gradated tones, and can look cartoony or posterized.”
This is the warm and fuzzy answer that visual people see. The truth behind it is that there is an enormous amount of math surrounding the manipulation of images as we are still dealing with discrete non-analog information. If you are good at following math, here are some articles
Image Processing and More Image processing
But I wasn’t the best at calculus and was fair at algebra and trig. But since I use Adobe’s LightRoom, quite a lot, I don’t have to be good at math. This stupid blog is to demonstrate the effect of Contrast on images using one of my favorite subjects..my neighbor’s dog.
This was the original image as shot from my Canon EOS Digital Rebel Xt. 1/250 @ f4.0. this image was shot in the Canon RAW format.
You can see that the original image is not really engaging. It’s blah. so lets try some things. Lowering the contrast, lowers the “difference in luminance or color that makes an object (or its representation in an image or display) distinguishable”. You can see it below. Everythign looks muted and unappealing.
So lets increase contrast the other direction.
Now everything “pops” The colors look more vibrant. I’m showing the entire develop panel to show that no other adjustments were made. One simple adjustment can take your images from zero to hero and you don’t need a ton of money and new gear to do it.
The GREAT thing about Adobe LightRoom is that if you like this look, then you can save this as a “User Preset”. then when you import images, you can apply your own “user Presets” to all images when you import them or apply them after imported.
After mucking about with some more of the sliders and adjustments here is a candidate for a final image.