Visual and special effects have a long history; they've been around since the dawn of filmmaking. Here are some great examples from silent films where the techniques used behind the scenes are still relevant today.
There are two terms used today for executing complex visual scenes: special effects (SFX) and visual effects (VFX). Special effects, also called practical effects, are all done in camera. Visual effects are those that require extra manipulation of the footage to get to the final result (CGI, masking, etc.). However, before 1970 the term SFX was used for both cases. Here are special effects from old silent films made completely in-camera:
Carefully planning and executing the perspective of the set sells the effect in this scene. Indeed, it was shot on a high building, but not as you may think.
The Black Pirate
With a little help from smart engineers, this is all in camera.
Impressive matte painting on glass is the secret behind this shot. It has been precisely placed in front of the panning camera. Not of less importance is the performance of Charlie Chaplin.
A very common way of making visual effects is double exposure. This technique requires blocking part of the image seen by the camera with a black object. This way the blocked part of the film is not exposed. Then the film is wound back and the scene is re-shot uncovering the blocked part.
Look at their makeup. It disappears after the hand passes above them. This is achieved by placing a filter in front of the camera at the right time, so it removes certain color casts. Of course shooting in black and white helps because the color of the makeup becomes a shade of light gray. It's the same as if you put a blue filter on a tungsten bulb; the result is neutralizing the orange cast and creating а daylight color from the bulb.
Little Lord Fauntleroy
One more example of double exposure to achieve cloning of a character several times in a scene. In order to achieve this, the matte cover had to be a very precise silhouette of the actress.
Double exposure again. Left side and right side of the camera frame have been covered partially. It's critical that neither the actress, nor the book move.
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