Follow Focus Finder for DSLR and Camcorder ( F1 Fits Slide Way) A follow focus is a focus control mechanism used in filmmaking with film cameras and in television production with professional video cameras. It is ergonomic rather than strictly necessary; in other words it does not contribute to the basic functionality of a camera but instead allows the operator to be more efficient and precise. This follow focus finder takes an important function in film shooting. Film movie camera lenses are manually focus. Cause there are many scenarios need to constantly change the focus. It's very inconvenient to operate the lens directly. So the follow focus finder provides a greater convenience. Further more, the making shallow depth of the field (such as virtual reality after and before) screen shot becomes reality since the emergence of the video SLR. And the current video SLR auto focus technology is extremely immature. So the follow focus finder will be the best choice.  The follow focus finder can let you shoots precisely, focus precisely and operate smoothly. Whether you're shooting with a fixed-lens camcorder, interchangeable cinema lens, or a video-capable DSLR camera, this machine will provide repeatable and accurate focusing. Features: With precise design and high technology. Make of high grade aluminum construction. Fits a camera with slide way. Completely gear-driven design for slip-free, accurate, and repeatable focus movement. With two slide way holes. Bright white marking disk. Completely gear driven design for slip-free and accurate movement. Adjustable locking system. Gear drive can be mounted from either side (works for both right-handed and left-handed). Mounts onto 15mm/0.59'' Rod Support (60mm/2.4'' center to center difference).                                                                                    Compatible with all DSLR cameras, video cameras. Compatible with industry standard 15mm Rods. With adjustable flexible gear belt.  Suitable for adjustable mount lens from 52mm-86mm. High quality and durable. Pretty easy to use. Specification: Fit rail distance: 60mm/2.4'' Fit rail diameter: 15mm/0.59'' Gears Nylon and ABS dial index adjustment: 360°   Gear Mod: Industry standard 0.8  Weight: Approx. 349g/ 12.3oz                                                                                         100% Brand New Color: Black Suitable for: Universal DSLR Cameras and Camcorders and DSLR Rig Canon EOS 1Ds MarkⅢ, EOS1D MarkⅣ, EOS 5D MarkⅡ, EOS 7D, EOS 60D, EOS 600D, EOS 550D etc Nikon D3X, D3S, D700, D300S, D7000, D90, D5100, D5000, D3100, D3000 etc Sony Alpha Series Such as: A850, A77  and NEX-5, NEX-3, NEX-7, NEX-5N, NEXC3  etc Panasonic AG-HMC153MC, GH-1, GH-2, GF-1, GF-2 etc Olympus Pen Series EP1, EP2, EP3, EPL1, EPL2. EPL3, EPM1 etc Package Includes: 1X Focus Follow Finder 1X Matching Gear Belt