If you're looking to do some remote focus pulling, the wireless systems can be a bit 'finicky'. A Wired electronic remote follow focus system works with a long cable so the camera operator can move about, and the puller can control focus with a remote video screen. This particular one (above) uses a basic '3.5mm stereo' cable for the remote tether. Looking back at some of the older videos, this new electronic follow focus has been a work in progress for at least several months. The final version finally has shown up on eBay with what looks like a similar beefy servo as in the Jag35 kit and starts at only $199 (seen here).
The video above has the Servo mounted on the stiff Zoom ring (not focus ring) to showcase it's strength. There are two different versions available. One with a A/B programmable focus points, and one is just a basic electronic follow focus. The speed of the movement can be adjusted on the remote as well. There's a few other videos showing the effectiveness of programmed A/B stops, and a closer look at the Remote (keep in mind that's the older version ff) on the eBay page (click here).
Maybe i'm late to the party, but i'm just finding this information now or maybe there is a newer (cheaper) version out. Proaim is looking to provide the cheapest electronic follow focus on the market. The Proaim e-Focus Electronic Follow Focus is a wired system (not wireless FF) and comes with two motors in case you need to have control over your zoom and focus rings. A 15mm clamp holds a remote in place, is powered by what looks like Sony NP-F style batteries, and presented in it's own travel bag. Obviously there will be some noise involved with any type of Electronic Follow Focus, and it would be interesting to see how accurate the e-Focus FF system is. I'm sure we'll be hearing more about it in the coming months, so keep your eyes open and let me know if there's some reviews online. You can see them online now via eBay (click here).
Proaim e-Focus Electronic DSLR Follow Focus System
Jag35 is up to something new and affordable. They are currently showing off their upcoming EFF - Electronic Follow Focus system. I have to admit, I can't say i've ever seen an Electronic Follow Focus being sold at this price, in fact the price is cheap compared to just about any follow focus system.
It's definitely a nice video demo showcasing both Zoom and Focus rings being adjusted simultaneously on a Canon 24-70mm F/2.8, but i'm interested in seeing more of it in use on an actual shoot. From the first video it's also something that comes with lots of noise, so be aware of when you might be able to use something like this. We'll see more when it's officially released in February, but there is a very very limited amount of Jag35 Electronic Follow Focus systems being offered right now for any early birds...