The Levels Command is a good way to manipulate the tonal values of the image sequence (e.g., to make animation flimsies as white as possible). As part of its function, the Levels dialogue box displays a histogram, which is a kind of bar chart that plots an image’s highlight, shadows, and gamma (or mid-tones) on a scale from 0 to 255. This gauge is set along the histogram’s horizontal axis. The number of pixels at each level is measured along the histogram’s vertical axis. Therefore, if there is a large amount of dark pixels in an image, the histogram will show a peak shape towards the left region of the guide.
Referring to the Levels dialogue box, there are three Input Level sliders that you are meant to manipulate, in order to adjust the black-point, white-point, and gamma (mid-tones) of an image. When you move the sliders towards the centre of the histogram, you will subsequently increase the overall contrast of the image.
To find the Levels Histogram, take the following steps:
- Referring to the Premiere Interface, locate the Effects Window (or go to the Main Menu > Window > Effects).
- From the Effects Options, go to Video Effects > Adjust > Levels. Click on the icon and drag it on top of the footage in the Timeline. The settings will then appear in the Effects Controls Window > Levels. Looking at the Effects Controls Window, where Levels is listed, you should notice a small icon to the right of the Levels list item. Clicking on that button will then open the Levels adjustment and histogram.
- Using the three Input Level sliders, when you move the black-point slider away from zero toward the right-side of the scale — towards white — the current levels at the black-point slider and those that are less than the black-point slider will then move to zero.
- As a result, as the black-level moves, the image’s entire tonal range of 0 to 255 will shift as the slider is moved. Increased dark values will begin to appear in the image.
- The opposite will occur as you shift the white-levels toward black. Increased highlight values will then appear in the image.
- The gamma slider allows you to alter the image’s mid-tone values, without changing the highlight or shadow points. As you move the slider to the left, the Levels adjustment shifts highlights together and the image will therefore appear to be lighter.
- Output levels compress the tonal range of an image into fewer values than 255 steps of grey. This function is used for artists intending to print images from Photoshop. For animation purposes, the input levels should suffice.