2011Cameras (Film/Video/HD) forum
Using servo-controlled zoom and focus on Canon DSLRs for live video work
15 years old. Gear and prices may have changed since.
What the thread found
- Canon DSLRs lack built-in video-style zoom servo controls that professional broadcast cameras have
- Servo zoom solutions for Canon DSLRs are extremely limited and expensive, with cinema-mount options costing thousands of dollars
- Still lenses exhibit focus tracking problems during zoom operations, including lens creep and inability to maintain focus throughout the zoom range
- Tokina and Canon zoom lenses with mechanical manual focus modes can work with external servo controllers like Microforce or gimbal-mounted controllers
- Stopping down aperture to around F4 can improve focus consistency with still lenses during zoom operations
- Some still lenses like the Canon 70-200mm f/2.8 and 16-35mm f/2.8 have been used successfully on video shoots despite not being parfocal
- Mechanical manual focus lenses with hard stops are more compatible with remote lens control systems than modern autofocus drive-by-wire designs
Depends on
- Solutions described are workarounds rather than integrated servo systems; none match the performance of professional ENG lens setups
- Affordable servo zoom options under $2000 were not available at the time of discussion
- Compatibility between specific lens models and servo controllers requires matching mechanical specifications
- Panasonic and Sony were developing servo-controlled lenses but used LANC control protocols incompatible with Canon systems
- Focus tracking reliability with still lenses varies depending on specific lens model and shooting conditions
- Most current Tokina zooms available at discussion time were for crop-sensor cameras only