Ripple Effect
Ripple effect for photos and video: rings spread from the middle of the frame like a stone dropped in still water. Set height, spacing and speed, free.
What is a ripple effect?
Drop a stone into still water and rings of waves spread out from where it landed. The water mostly bobs up and down as each ring passes, so the wave travels outward while the water stays put. Waves of different lengths travel at different speeds, which is why the messy splash soon sorts itself into a tidy train of rings.
The smallest ripples, under about 1.7 cm from crest to crest, are held up by surface tension more than gravity. Meteorologists and physicists call them capillary waves.
It's the same image behind the English phrase for one event whose consequences keep spreading outward.
How to add a water ripple effect
The page opens on Choppy, with tall, tight rings at Amount 30 and Frequency 20. Ripple is gentler at 10 and 8, and Calm is a faint shimmer at Amount 4.
Amount sets how tall the ripples are, from 0 to 100, Frequency how many rings fit into one frame height, and Speed how fast they travel outward. The rings always spread from the center of the frame, so put the spot you want disturbed right in the middle.
Settings for a lake shimmer, a stone drop and a slow dream wave
Lake shimmer: Calm at Amount 4, Frequency 8 and Speed 0.5. Small, slow rings make still water look alive without bending the shoreline out of shape.
Stone drop: Choppy at Speed 2, so tight, tall rings rush outward and break up the detail in the picture.
Slow dream wave: Amount 40, Frequency 6 and Speed 0.5. A few broad waves bend whole shapes without fraying every edge, the old film cue for a memory or a dream.
How the ripples bend the picture
Look into rippled water and the bottom seems to wobble, because each slope of the surface bends the light passing through it. This effect does that to a picture. Every pixel gets pushed toward or away from the center of the frame by a sine wave of its distance, and the wave moves outward over time.
The push weakens with distance, and by the top and bottom edges of the frame it's down to 40 percent of its strength in the middle. Amount is measured in pixels of a 1080p frame and scaled to your picture, so the rippling looks the same at any export size.
How do I loop a ripple GIF without a jump?
At any point in the frame, the rings come around every half pi seconds at Speed 1, about 1.571, and faster in proportion as you raise Speed. A 5-second clip at Speed 1 holds 3.18 waves, so it stops about a fifth of the way into one and the loop jumps.
Pick a Speed that fits whole waves into the clip instead. Speed 2.2 puts 7.003 waves into 5 seconds, and Speed 1.1 does the same in 10, because 22 divided by 7 is within 0.05 percent of pi. The leftover, 0.3 percent of a wave, is too small to see. For 3 seconds, Speed 2.1 fits 4.011 waves.
With these speeds, leave Seamless loop at Off. Its crossfade shortens the export by the length of the fade and throws off the count. For any other length, a ¼ s or ½ s Seamless loop hides the jump in the movement of the water.
Saving ripples as video
The GIF export stores every frame whole, so its size depends on the length of the clip more than the motion in it. Two seconds at 960 by 540 and 30 frames a second came to 4.2 MB with the default ripple, 4.1 MB with the same frame standing still and 4.7 MB with Choppy.
A GIF optimizer that only keeps the pixels that change can't save much, because a ripple moves nearly all of them. At its default 128 colors, the GIF tool on the Image Tools hub shrank the still clip to 0.06 MB, but the default ripple only to 2.8 MB and Choppy to 3.8 MB. MP4 and WebM predict each frame from the one before, so they're the formats to use for rippling water.
For water seen through patterned glass that doesn't move, the Ripple pattern in Fluted Glass Effect gives you fixed waves.