Acorn: Levels

Levels

levels.acorn

To bring up the levels graph, go to Image ▸ Levels (⌘L)

Levels are a different way of looking at an image. Instead of the picture being displayed in its normal viewable state, it is shown as a bar graph called a histogram. The histogram is essentially a count of how many times each color shows up in the image. In the image above dark colors are showing up a lot, as you can see by the spike in the graph at the left end. On the other hand there are not many lighter colors in the image, as you can see by the low point on the right.

To correct or modify levels, simply drag the two triangular slider controls on the left and right sides at the bottom of the histogram. Doing so will instantly change the image on your canvas, hopefully for the better. To improve this image, leave the black slider on the left alone since it is already under the color peaks. Pull the white slider in towards the left until it rests under the start of the slope. Every image is different, so look at your changes and make sure they are to your liking before you hit 'OK.'

Example Image:

levels1.acorn

Before Levels Adjusted

levels2.acorn

After Levels Adjusted

Below the histogram is an Output Black slider, as well as an Output White slider. These control how black the blacks are, as well as the whites. Pulling these sliders around will change the contrast. Try experimenting with them to get the hang of it.

Also try using Image ▸ Auto Levels. It will attempt to automatically move the sliders in to the right spots. This can be a great option if you are in a hurry.

Photo Credit