Post Production: Understanding Color Correction
Color correction can be used in post production. Most current color correction is done digitally, though traditionally a chemical process was used on film. Think about the colors used in the Wizard of Oz. This was originally shot in black and white and then color was added. There are several different types of color correction that can be used on your video.
Primary and Secondary
Primary color correction is done across the entire image. It is possible to control the different intensities of colors in the entire picture. Blue, red, mid tones, green, white and black colors can all be changed across the entire picture. Many times altering the intensity of 1 color can completely change the look of the image. Secondary color correction will alter the saturation, luminance and hue of yellow, magenta, cyan, blue, green and red. These secondary corrections will have a minimum effect on the other colors in the spectrum. By using digital color correction it is possible to change the color of specific images and sections within the scene instead of having to apply that color correction to the entire picture. It is possible to alter color tints and other visual treatments.
Besides the traditional primary and secondary tools, digital color correction also can use masks, power windows and mattes. By using mattes and masks, typically found in software such as Photoshop, it is possible to highlight an object in the background without altering the rest of the frame. Alternatively, you can change the color on everything else except what has been selected. Different digital filters can also be used to sharpen, soften or mimic different effects. These digital tools also use motion tracking. You will need to move the color mask that is being used as the subject moves through different images. Motion tracking is frequently used in post production as it can save on cost and money by being done in post.
Color Correction at Home
Most at home videos can use color correction to change any images that do not look right. It is important to make sure that it is not the monitor that is causing the color issues. Check your video on several screens first. Sometimes you may need to change the settings of the monitor and not the actual color of the film. Many times, only a few scenes will need color correction and this is normally due to a mixed light source or bad white balance. A white balance filter is the easiest way to fix these issues. There are several tools in the white balance to use, such as tint, temperature or saturation filter. Basically a temperature color correction will change the white balance between orange and blue. If your image is too orange or blue then a temperature shift is the best tool to use. The tint filter deals with green and violet colors. Normally you will only need to make slight changes to make a large color correction different. Video editing software will have several different color correction options available and once you determine what the issue the correct tool can be used to fix the problem.