Color Correct Movies (Video Grading) on the iPad

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If you've browsed YouTube videos at all, you'll see alot of movies that would benefit from a bit of color correction. If your video has a blue, yellow, or orange color tint, the white balance on your camera isn't set. Fixing this problem after the fact in still photography is a basic skill, but doing the same for video is still a pretty advanced task. It is mostly reserved for high power software like Final Cut Pro and Adobe After Effects, but remember there's an app for that. Here is how you color correct video on the iPad.

Most video projects aren't one long continuous take. They usually combine multiple takes from different view points, often recorded at different time and by different people and equipment. When you are editing all this footage together, you don't want constant color shifts.

Let's get rid of any color tints by neutralizing any white or grey areas. To do this we need VideGrade by Fidel Lainez. Step one download, install and start the app.

VideoGrade starts out fairly simply... select a video in your camera roll. This kind of video processing works best if you apply it over your shoot footage, rather than trying it an edited piece. Edited footage may contain slightly different color tints over different segments of the video.

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I will be editing a video of kittens playing the piano I saved from YouTube (see how). You can see the yellow tint (see the wall trim, piano keys and the kitten fur).

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Indoor footage often will often have yellow tints like this. Start by adjusting the global color temperature. Color temperature refers to the color of the ambient light the footage was shoot in. Different light sources produce different color of light (the sun, shade, tungsten lights, LED lights, etc.).

Tap the middle thermometer icon in the middle row of icons under the video preview. This will allow you to adjust the color of the video by identifying the temperature of the ambient light.

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Adjusting the white balance by ambient light color temperature (color is measured by °K) is pretty simple. Usually there is a slider. On one side of the slider is the color blue and at the other end yellow (or red). Look at the image/video and look for area that should be grey or white. Based on this area move the slider to toward the color the area is favoring. Here is video is obviously yellow (indoor lighting is often yellow), so move the slider toward yellow (usually to the right).

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Here you can see much of the yellow color cast is gone. The kitten's fur and the wall trimming is more white. It isn't totally gone though and the slider is all the way to the right. Often apps don't provide enough of a color adjustment. The yellow side of the slider goes all the way to red, and many programs also provide a whole other slider (called Tint) that adjust between green and magenta. VideoGrade also has this slider (it is hidden in a separate area).

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Tap the eye dropper icon (Tint). Now tap the Global button. Normally the Tint control is a slider between green and magenta. And you can replicate this slider in VideoGrade by selecting either green or magenta with the color picker. VideoGrade automatically sets the other end of the slider to the color you selected's complimentary color. For our video the blue slider (from Color Temperature) bottomed out, so lets continue the blue/yellow adjustment. Select a royal blue color. Then move the slider to the right, until your greys and whites don't have a color cast.

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At about 30%, the yellow color cast is gone.

VideoGrade's tint control is pretty powerful. By selecting any color you should be able to fix any color cast, but if you aren't sure what to choose. I suggest either blue/yellow or green/magenta and use grey/white areas as a reference.

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Tap the back button and you can make localized adjustments in highlights (light)/mid-tones (medium)/ shadows (dark) areas.

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If you want the preview image you are basing your color adjustments on to be different, tap the movie icon on the left of the preview window. Now slide the bottom film strip until the playhead line (and preview window) shows the desired frame of the movie.

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You can see our color adjustment applies to the entire movie. All your shots in the same lighting environment should have similar settings, so lets save a preset. Tap the two-button mouse looking icon, to save and load presets.

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We are done now, lets save the movie to the camera roll. Tap the big green checkmark.

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Choose a resolution for the video.

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Working... this is actually pretty fast!

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...and we are done. The movie is in your camera roll. If you want to see it tap the "View video" button, or go to the Photos app.