Canon XJ27x6.5B AF Version HD Box Lens

Canon unique technology “Auto Focus System”

The need for an "Auto Focus System" in studio production

In HDTV systems that use the 2/3-inch format where typical studio settings might be, for instance, an aperture

setting of f/2.8 and a focal length of 35 mm with a distance of 4.5 m from the front lens to the subject, the front

depth of field is a mere 420 mm or less. The same settings in an SDTV system give a front depth of field of

roughly 800 mm, demonstrating that the depth of field in an HDTV system is around half that in a similar SDTV

system.

As a result, camera operators must continually work harder than in the past to maintain the focus, depending

on the sensitivity of the focusing adjustments. This imposes a fatigue factor over time as they must also be attentive

to image framing and camera moves that are actually the more creative aspect of their job.

Canon's unique Auto Focus Technology you can trust

What professional broadcast crews require in an AF system is

“reliability”. Such AF systems must be capable of accurately capturing

the images intended by the content producers.

The XJ27x6.5B AF uses Canon's own " TTL-Secondary Image

Registration Phase-detection System", which is a version of the reliable

AF system used in Canon’s single lens series reflex still cameras that

has been customized for motion imaging with broadcast lenses. It is

basically the same as the AF system first incorporated into Canon's long

zoom field lens XJ100x9.3B AF in 2007, but uses optimized algorithms

and control software to further enhance the precision available in studio

production environments.

Features of Canon’s “Auto Focus System”

! Extremely high focusing accuracy in full HDTV specifications

! Ability to focus from a completely de-focused status without hunting

! Ability to focus on a high speed moving object

! Focusing speed can be varied to suit the scene

! Size and position of the AF frame (target area) in the camera VF can be

changed from the Focus Demand FDJ-P31/P41.