Analyze the Grain

Before you can analyze grain, you must set up viewports such that you can see the source image. Usually, you want to see the target image at the same time, so you may want to use more than one viewport.

You may already be able to see the source image if it is the background for the composite and, for example, the front image has a matte. (If the front image is the same size as the background, the foreground needs a matte or else you will not be able to see the background.)

Note: The added grain does not affect the matte. Also note, you should create a matte before re-graining specific areas of a clip. For example, if you match using the highlights of the target image and then create the matte, the highlights may not even be there anymore.

The Match Grain picker extracts the intensity of the grain in each channel as well as information needed to produce the desired average grain size.

Note: When selecting areas for analysis, select areas of uniform color with no image detail. Otherwise, you will obtain bad control points in the granularity curves and wrong grain strength for some colors.

To analyze grain:

1. Make sure you can see the source image.

Usually, you want to see the target also, but it is not required. Use more than one viewport if necessary.

For example, make another viewport active and double-click the appropriate Footage operator in the Workspace panel.

2. Show the Add Grain Controls panel.

If you double-clicked another operator in step 1, you need to click the Add Grain operator in the Workspace panel to show its controls again.

Note: The Add Grain operator works in context, like the Discreet Keyer and Color Corrector operators. This means you can see the rest of the composite while adjusting the grain. (You do not need to double-click the Add Grain operator.)

Notice all the RGB curves in the curve editor are flat by default.

3. Click the Match Grain tool.



Note: When you use the Match Grain tool with a film stock, the gain only scales the built-in granularity curve. When you use the Match Grain tool with the Custom option, the sample determines the granularity curve itself.

4. Draw a selection box on one of the major colors in the source image. Be careful to select areas of uniform color with no image detail.

Note: You should not sample from the target image you are working on.

Control points appear in the appropriate channels of the curve editor; the points reflect the extracted intensity for the average luma of the selected grain field.



5. Draw a selection box in the source image.

Control points are added to the curve for the three colors at the same time.

Note: Repeat these steps as necessary and try to sample areas of the image of all intensities (shadows, midtones, and highlights). In most cases, these are the only steps you will have to take to get a perfect match.

6. You can continue the process by comparing the grain.