Flashing Lights Like Police Lights

mksalva  wrote Is there a particular effect or preset where I can simulate nearby flashing police lights in a scene? I do not want to actually show the police lights, but only a scene that might be 20 or 25 yards away from the police lights. The lights would be hitting the scene and the characters. Thanks!

If you want to simulate the reflected lights from a police car you don't want to use Optical Flares or 3D lights, you need to decide which parts of the scene are going to pick up reflections and create some kind of a matte for those areas so you can use a blend mode to add light to the scene. The most efficient technique depends entirely on the shot. The more detail and reflective surfaces in the shot the more work you have to go to.

Take this video from Adobe Stock:

I just started to break down the shot so I could design the matte. If I'm really lucky I might be able to make a high contrast copy of the footage using Colorama to do a lot of the masking. The first part of step two would look like this:

The goal here is to start creating a matte for the actor and maybe the wall. Throwing a black solid below the footage, then doing some roto gives me this:

That's a pretty good start on a track matte for a lights layer. Pre-compose, add a blue solid, set up the track matte and you get this:

I doubled up the blue layers to get more color and the mattes need work. This should give you some ideas. It would probably take me about two hours to do the roto necessary and set up the mattes and the overlays with blend modes to make the scene work.

Getting the lights to flash is the easy part, creating the mattes is the hard part. I would want to add a shadow on the wall, pick up a little of the reflections in the sidewalk, throw a few highlights on the lamp posts, and fiddle with the color a lot before I would believe that the cops were just out of frame.

Show us your shot and maybe we can point you in the right direction.

Yes you can do it natively without any plugin as the RobShultz suggestion, but if you need it in professional way and you want to invest in a helpful plugin you can try optical flare plugin from VIDEO COPILOT | After Effects

You might want to put the scene in 3D space and create some red and blue lights. You can keyframe the light intensity To make them flash.