How to create and film ghost special effects

Question

I need to film a piece that is supernatural in nature and has several characters that are ghosts. I've thought of numerous ways of accomplishing this but would like some suggestions on which would be the easiest and produce the best results.

Fortunately I am going to be shooting at a location and I would like to have several camera angles as well as a moving camera for some scenes. The problem is I have several characters that are ghosts. I've thought about planning every character's position carefully and then doing a lot of room shots, angles, and movements, and then putting up green screens and filming each character in the same position where they would be in the video so that I may make them transparent and give them a ghostly effect. That seems like it's very complicated though and it also seems like the editing will be a pain.

Is there any easier or more effective way to give several characters a ghost effect without having to resort to green screening them? I have thought about make-up. Also, if green screening is the way to go, would it be wisest to take the green screen on location and put it over the backgrounds and run the camera through the same courses as I did when shooting the background?

Answer 1

There are so many interesting ways to do this.

One of the easiest ways (in-camera, no post production work) is to use a piece of glass. Film Riot did a tutorial on it, they explain it best, see below:

Or you could go with a bit of post production work, after effects being my go to tool that I use. Add a background video layer (without ghost), then add your ghostly image, same shot, but this time your ghostly image is brightly lit and everything else is dark. Then change the mode of the ghostly layer to 'add' (or other to create different effects) to create the ghostly effect. See tutorial below:

Hope that helps your ghostly scenes.

Answer 2

If you ditch your plan to use moving shots you can do a simple background subtraction which will look a lot cleaner than greenscreen given this is a low cost production.

This works by having a shot of your scene without any actor in it e.g. only the background and then film your scene with the actors without moving the camera, afterwards you can use a program like After Effects to do a background subtraction, so everything that is different to your previous background only shot will be usable as a mask or the inverse.

That is pretty much the easiest way to achieve such an effect. Though it is limited and you have to be very careful about what and how you shoot your scenes.

• Do not move the camera in the slightest way during every scene, the background needs to as pixel exact as possible in both shots.
• Do not have a moving background behind any of the actors, you can have moving objects in the background but they can not intersect with the actor. You can later rough masks to remove moving parts in the background that don't intersect with the actor. It's still possible to have intersecting objects but you will have to reside to rotoscoping which can be a pain in the ass.
• If the "ghost effect" you want to give your characters are meant to be visually different for every character you also do not want actors to touch each other or you have to reside to rotoscoping again which in that case can be even more difficult if you have to mask things like fingers for every frame.
• Avoid noise in your camera footage and do not change any setting in the cameras between the plane shot and the actual scene shot

Greenscreen is not that hard to use but diffrences in camera angle, camera movement and focal length can make you characters look a bit funny and it will be very obvious that they were shot infront of a greenscreen.

If you decide to use greenscreen I suggest you use a motorized dolly for moving shots that can be programmed for specific movements. You can also mix both techniques and use greenscreen only for moving shots but if you want to do this with the least work possible I would not use moving shots and greenscreen at all.

Answer 3

A few good options to consider:

1. If you disobey the 180 degree shutter rule, and shoot at a lower shutter speed, you'll get more motion blur in your shot. Whether or not this is what you're going for is up for debate (it'll produce a dream sequence - ghostly like effect), but it's worth trying out. Note that EVERYTHING in your shot with have increased motion blur, not just your actors. So, maybe make sure you plan out your shots to have a still background + just ghost characters.

2. As opposed to green screening your subjects into your background (often looks superficial unless your super good at matching the RGB channel values for the foreground and background), you might consider rotoscoping the actors w/effects such as a slight glow, maybe a tint to make them less saturated, maybe track their movements and add some smoke particle effects, etc. While this is a pain in the butt, I think it'll look more realistic than the green screen route.

Answer 4

If you don't mind using a computer. There is a great solution (for me at least) which is called Blender, if you don't know about it, it is a free sortware that lets you do 3D and mix 3D with video, but it also lets you do video editing and a lot more staff. Google for Blender.

With that you don't need to be very precise to record your ghosts, just record the people separately and in Blender create a plane with each of the ghosts in 3D, assign them the transparency factor you wish, do whatever special effects you might like to do in 3D or just visual, like halos around ghosts and that stuff, place those planes and ghost as you see fit your needs in the scene and render your video.

This way, ghosts can walk in front of AND behind people on set (but for this you will need everybody, ghosts and not ghosts to be recorded using chroma).

Here are two images one from Blender's 3D view port and another one with the final result.

I have done a simple (without big halos and staff) example in Blender's compositor, you can see the nodes and the final result in the background. You can adjust transparency and apply more filters and effects.

Answer 5

For fixed camera shots, if you plan the shot so that they don't pass over any other actors, you can simply shoot them on one plate and shoot the rest of the actors on another plate. You then mask the one plate over the other so that they appear semi-transparent and possibly use a blurred difference mask for adding an edge glow.

Greenscreening overall is probably the easiest, though it probably won't produce the best quality result possible. As long as you plan your shots well (try to avoid wide shots where the movement around the scene may be awkward to match), then it shouldn't be too hard to put together. Even lighting shouldn't particularly matter since ghosts are often depicted as self lighting and so the glow will remove any inconsistency the eye might see in how the subject is lit. Note that the big caveat for this to work is you need to be applying color and lighting effects to the ghost that make it so that it shouldn't match the lighting of the scene it is shot in.