D-Focus has been around for a little while, making some very cheap follow focus systems for DSLRâ€™s. There is a Dfocus V2 for $119, lens gears for thirty bucks a piece, or eighty for three. The gears are a strange variety with individual screws for different size lenses. A pain to change all the screws, but with that price you may be able to get a gear for each lens.
You get what you pay for with this equipment. The gear is very rudimentary looking. However, if it works, it works. A follow focus is a must have for video shooting with HD DSLRâ€™s. The Dfocus stuff could be a very inexpensive solution. Check out the website Here.