The colour effects in Video by Zaweba and when to use them
Black and white, sepia, split toning, gradient map, leave colour, channel mixer and more: the colour effects in Video by Zaweba and the jobs they suit.
Colour correction makes a shot look right. Colour effects in Video by Zaweba are about doing something deliberate with colour: turning a scene black and white, leaving only a red umbrella in colour, giving an old photo a sepia tone, or mapping a picture to a two-colour poster look. They are found in the Effects tab and are applied like any other effect, to a clip, a track, a source file or an adjustment layer.
The full family
There are quite a few: hue and saturation with colourise, levels, black and white with filters, sepia, tint, gradient map, split toning, invert, posterise, threshold, leave colour, change colour, photo filter, channel mixer, auto contrast, vignette, exposure, and brightness and contrast. Some overlap with the colour controls in the Inspector, which is useful in its own right, because as effects they can be stacked, masked, saved as presets and keyframed.
Turning a picture black and white
The black and white effect has filters, which work like the coloured filters photographers once screwed onto lenses for black and white film. A red filter darkens blue skies and makes clouds stand out. A green one lightens foliage. Trying a few filters on the same shot shows how different a monochrome picture can look depending on which colours become light and which become dark.
Sepia and tint take a black and white picture a step further, giving it a warm brown or any single colour. They suit flashbacks and old archive looks.
Leave colour and change colour
Leave colour keeps one colour and drains everything else to grey. The classic use is a single red object in an otherwise grey scene. It works best when the colour you keep is distinct from everything else in frame, so a red coat against a blue street is easy and a red coat beside a brick wall is not.
Change colour swaps one colour for another. It is a quick way to turn a blue car green or change the colour of a sign without a full secondary grade.
Toning effects
Split toning puts one colour in the shadows and another in the highlights. A cool blue in the darks and warm amber in the lights is a familiar film look, and a little goes a long way. Gradient map replaces the brightness of the picture with a range of colours you choose, from darkest to lightest, which can make a strong graphic look for title sequences and music videos. Photo filter imitates a coloured lens filter, warming or cooling the shot in a natural looking way.
Utility effects
Levels, exposure, brightness and contrast, and auto contrast are practical tools. As effects rather than Inspector settings, they can be put on an adjustment layer or applied with Only inside mask, to brighten one part of the frame only. The channel mixer lets you blend the red, green and blue channels into each other, which is a precise way to build a custom black and white or fix an odd cast.
Invert, posterise and threshold are strong graphic effects. Threshold turns the picture into pure black and white with no greys, posterise cuts it into a few flat bands of colour, and invert flips everything to its opposite. They are mostly for stylised work and transitions.
Vignette darkens the edges of the frame to draw the eye to the middle. Keep it subtle unless you want it to be noticed.
Avoiding the obvious pitfalls
Correct first, then stylise. A colour effect on a badly balanced shot carries the problem through, and leave colour in particular gets confused if the colour you want to keep has drifted.
Watch for colour effects stacking on top of a LUT or a built-in look. Two treatments that both change the mood often clash. Pick one main look and use colour effects for specific touches.
And keyframe when it helps. A scene that slowly drains to black and white, or a colour that floods back in at an emotional moment, is easy to do by animating the effect's strength in Video by Zaweba.
