Early film cameras used hand-cranks to advance the celluloid in the camera, and even though there were plenty of good operators, there was still a unique look to the resulting footage. There would usually be slight variations in the frame rate, which would give you faster/slower motion as well as changes in the exposure. You also get a lesser version of this effect at the beginning and end of a take with film.

Stu Maschwitz, author of the The DV Rebel's Guide, filmmaker, and VFX artist (he's most recently worked with Red Giant Software), developed Prolost Handcrank as a simple and fast way to get this old film look in After EffectsHere is an example of this plugin in use:

Some features of Handcrank:

  • Works with After Effects CS6 1.0 and Up, Including Creative Cloud
  • Your footage automatically changes speed and exposure in sync with the virtual frame rate.
  • Easily adjust the amount of variation in the hand crank effect.
  • The realistic exposure effect can be adjusted to taste too.
  • Adjust the random seed for infinitely varrying effects.
  • Works with any footage, at any frame rate, video or log.
  • Renders blazing fast.
  • Price: $11.99

This effect has also been used extensively by Tony Scott in films like Domino and Man on Fire:

Here's a great story on a hand-crank camera that gives you an idea of how this all worked:

Pieter-Rim de Kroon, award-winning filmmaker from Amsterdam, found this 1900-build German Oskar Kine-Messter camera in virtually perfect state, fell in love with it and wants to revive its glory... This is the story and the kick off of a series of five in which we will have you re-discover the art and sensation of observing.

Stu also showed off an example of a PSA he directed where he did this effect by hand, something you can learn how to do in his book. There are also some great tutorials online showing you how to do it (this particular one even references Stu's book):

The plugin is about $12, and you can buy it over on the Prolost store. You can also find a number of other great plugins there as well.

Source: Prolost