Mirror, ripple and corner pin: distort effects in Video

Distort effects move pixels around instead of changing their colour. In Video by Zaweba the group includes mirror, kaleidoscope, tile, spherise, twirl, wave warp, ripple, lens distortion, corner pin, offset, magnify, turbulent displace, edge feather and flip. Some are for fun, some are workhorses, and a couple solve problems you will meet surprisingly often.

The practical ones

Corner pin is the one most people end up needing. It lets you move each of the four corners of a picture independently, so you can place a video onto a screen, a sign, a picture frame or a page that is seen at an angle. Drop the clip on a track above the background, apply corner pin and drag each corner to the matching corner of the screen in the shot. If the camera moves, keyframe the corners, and the mask tracking tools elsewhere in the app can help with the motion of the surface.

Flip mirrors the picture left to right or top to bottom. It is handy when someone looks out of the wrong side of the frame for the cut, though be careful with text, logos and clocks, which give a flip away.

Offset slides the picture and wraps it round, so what leaves one edge comes back on the other. That makes it useful for checking whether a texture tiles, and for animated scrolling backgrounds.

Edge feather softens the edges of the picture, which helps an inset clip blend into the background instead of sitting on it like a sticker.

Magnify enlarges a circular area, like a magnifying glass, which is good for pointing at a detail in a tutorial or screen recording.

The creative ones

Mirror reflects one half of the picture onto the other, creating symmetrical images. Kaleidoscope repeats a slice of the picture round a centre, like the toy. Tile repeats the picture in a grid. These three are favourites for music videos and abstract backgrounds.

Spherise bulges the picture as if it were on a ball. Twirl swirls it round a centre. Wave warp and ripple make it move like water, either in regular waves or as rings spreading outwards. Turbulent displace pushes pixels around in an irregular, organic way, good for heat haze, underwater shots or a dream that starts to break up.

Lens distortion bends the picture like a wide angle lens, or straightens it. You can use it to add a fish eye look, or to reduce the curve of straight lines in footage from a wide action camera.

Animating distortions

Most distortions look best when they move. A ripple that spreads from the centre and settles, or a twirl that builds and releases, works well as a transition or to show a character's confusion. Every effect setting with a stopwatch can be keyframed in Video by Zaweba, and the keyframe graph lets you shape how quickly the change speeds up and slows down.

To distort only part of the frame, use the Only inside mask option on the effect. A heat haze can then shimmer above a road and leave the sky alone.

Mistakes to look out for

Distorting the edges of the frame can pull in empty space or stretch pixels at the borders. Scale the clip up slightly, or crop, so the damaged edges are outside the frame.

Small text distorts badly, so if a title sits on a clip you are rippling, put the title on a higher track where the effect can't reach it.

Lastly, distortions combined with heavy blurs or glows can slow the preview. Check the badges in the Effects tab and, if needed, use render previews for those stretches while you work.

Distort effects in Video by Zaweba reward playing around. Start with corner pin and flip for everyday jobs, then explore the rest when a project calls for something stranger.