Has anyone out there managed to make or buy an attachment similar to the Fifty Dollar Follow Focus - but powered and varispeed?

I use Magic Lantern on my Rebel T3i and there is an option to use the + and - controls to zoom, but it has a hard start and end ... and the zoom is effected by reducing the area used on the sensor, not by operaing the zoom within the lens itself.

Any ideas?

Many thanks,

Harry.

The closest out-of-the-box product I know of is the Kessler Cinedrive FIZ motor, but that's part of a motion control system. CineDrive F.I.Z. Motor (http://www.kesslercrane.com/product-p/cinedrive_fiz.htm)

I've had this article bookmarked for a long time: Adapting Servo Zoom Lenses for Smooth-Zooming DSLR Production, Part 1 - Streaming Media Producer (http://www.streamingmedia.com/Producer/Articles/ReadArticle.aspx?ArticleID=80668&PageNum=2)

I have an old Fujinon servo zoom lens that I've been meaning to try out with my 70D. Now that the 70D has autofocus pretty much locked down, a decent servo zoom is the only thing I really miss when I use a DSLR.

Jag35 makes a wireless follow focus with 2 channels than can also drive a zoom ring. You should be able to find it on their site. Not sure if that's what you're looking for but it'll get you close. Forget the price but $1300ish. I think they have a wired version for 1/3rd that price.