An image can be greatly enhanced by knowing how to implement tonal contrasts. A washed out photo can be made more vibrant or more striking. Used often in black and white photography, tonal contrast is the arrangement of black, white, and all the various shades of gray in between.
High tonal contrast is when the blacks and whites are very pronounced, with hardly any shades of gray visible in the image. Low tonal contrast is when the image is mostly shades of gray with no pure blacks or whites. Medium tonal contrast would be a mixture of whites, blacks and grays. Bear in mind that in our mind’s eye, the light shades in an image will appear to move forward while dark shades retreat in the background.
Tonal contrast can be adjusted in post processing. I am currently using Adobe Photoshop CS2 as my photo editing software but whatever you’ve got, there should be tools similar to curves, channels or the gradient map to adjust image contrast.
The photo on the left is the original image in color. It was taken during an overcast afternoon. The towel is white but in the shot, it is almost as gray as the concrete wall behind it. There are no blacks or whites that are obvious so we can say this is a low contrast image. Since there isn’t much contrast, the image looks very flat and two dimensional. To get a high tonal contrast, I used a simple curves adjustment. The grays dramatically lessened and the towel became whiter while the background wall darkened. Going a step further, I used the gradient map to change the image from colored to black and white. Now the towel appears to have moved to the foreground with lots of dark empty space in the back.
Tonal contrast can also be applied to colored photos with fantastic results. The original image on the left looks dull and bland. After applying tonal contrast, the darker and lighter areas are more exaggerated and the result (right photo) is a more vibrant looking rooster.
It is easy to overdo tonal contrast and there is the danger that the dark and light areas might become too amplified that the fine details found in medium tones will no longer be visible. A light hand is often enough to show your image at its best.
Tags: how to use tonal contrasts, tonal contrasts in photography