Color correction: Giving your movie a blockbuster shine.
(An excerpt from my new forthcoming film book, "Making Your First Blockbuster", due early 2019 published by Michael Wiese Productions.)
Color correction, or sometimes referred to as grading or timing, takes place after editing, and is a very important part of the finishing process. Color correction/grading can be a wonderful tool to enhance or technically improve your blockbuster. On most projects you would have a dedicated colorist to do this job but on smaller budgeted films, this role might fall to the editor. You can color correct in your NLE of choice or in your compositing software, or in a dedicated grading and finishing package like DaVinci Resolve. Each package might refer to things slightly differently or have controls in different places, but they all do the same thing: to change the luminance and color of the images. You correct the image for three reasons:
To balance the colors and brightness on shots in the same scene that were perhaps filmed at different times or places but must match each other. Maybe the sun went in, or the lighting was slightly different on the second day when you grabbed those last few shots. Grading now means you can make everything look like it was filmed at the same time.
For the “look” of the film. We’ve all seen films that have a certain color palette to them. Maybe a blueish tint, or dark and gloomy, or warm and fuzzy. You can give your film a desired look to tell help your story.
In order to meet the technical standards of the broadcaster or distributor. Films and programs are quality-controlled to guarantee the colors and brightness levels are within legal parameters. If the whites are too bright (sometimes referred to as “clipping”), the grade can bring this in line. Or maybe some of the colors are bleeding into each other, which too can be detected here.
When filming your blockbuster, you can choose whether you shoot with a log profile, or in the more traditional, linear Rec. 709 color space. Log (logarithmic color space) is designed to give the DP and the grader a large dynamic range between the darker and lighter areas of the imagery. Of course, you don’t have to shoot log, as filming in the Rec. 709 linear color space still has a good dynamic range; log, however, offers you a little more latitude. But if you have the option and a good grader on board, then shoot in a log profile. Log files are captured flat with the contrast and saturation low in order to give you more options when you correct and grade your footage.
When correcting, the first or primary color correction pass is about matching the blacks, mid-tones, highlights, and white balance, from shot to shot and getting a good overall exposure. The colorist uses the secondary pass to look at skin tones, and isolating particular areas of the frame to be adjusted. More sophisticated grading programs such as DaVinci’s Resolve or FilmLight’s Baselight allow you to use tools such as “power windows.” A power window is a masking tool where the grader can highlight part of the image by drawing a small mask or outline around it and only affect the areas within that space. So if the whole image is lit and balanced well, but the doorway area is a little bright, then just this area can be fixed without affecting the image as a whole. You can even track the movements of an actor’s face and brighten or darken them as they move.
Once all balanced you can then give the image on a particular “look” if you so desire. Maybe you want it high contrast, low contrast, make things looks magical by adding diffusion, desaturate the color to give it a raw and gritty feel . . . the choice is yours. What look you give your film is purely down to the creative choices of the grader, the DP, and the director. There is no right or wrong, just their individual tastes. When color correcting and giving your picture a look, be mindful of forcing something on the film that doesn’t work. I made a film once where I knew I wanted a certain look in the grade. When I got to the edit and applied it, my gut told me instantly that it didn’t work. The look applied was too gloomy for the subject matter. It looked good on the other film I saw it applied to, but not on my film. The trick here is to listen to this gut feeling when something isn’t right. Don’t force something through just because you knew it had to look that way ever since you began thinking of the film.
There are a number of approaches available to help create that blockbuster sheen. One is to apply an S-curve. By adding a couple of points along the curve tool once applied, you can subtly make the blacks darker and push the highlights more. It makes the image a little more contrast-laden, a look that is sometimes associated with film stock. It’s called an S-curve because by adding the two points one a third up from the bottom and another about a third down from the top, creates a shallow looking S on the controls. By moving any points along the curve you’re remapping the input brightness or color levels of the source footage to new output levels, thus making things brighter or darker. A vignette is another tool, which slightly darkens the edge of your image and forces the eye to the middle of the frame making the subject “pop” a little. Desaturating the colors a little is another possible option.
The S-curve in action in Avid's color correction workspace.
Color presets are also available in NLE and grading packages, which can be drag and dropped on to your footage to give it a particular look or shine or even to emulate film stocks. These presets can then be tweaked and adjustments to suit your needs. These same looks can be achieved from scratch working off the original footage and adjusting the color and luminance levels but the presets offer a nice shortcut if time is pressing or you want to see a few possible options. Of course, these are just a few of many approaches that can be used and played with. It all depends on what film you’re making and the story you’re telling. Below you can see examples of the original log footage, the shot with an S-curve and vignette applied, and a couple of different looks.
Finally, the director of photography should also be in the room when the corrections are taking place, as this part of the process is an extension of their work. They might be using the grade to correct a few things they didn’t have time to change during shooting, or to make sure the overall look being applied is in keeping with their original vision.
"Making Your First Blockbuster" is due to be released early 2019 from Michael Wiese Productions.