User Manual

3.3 Dual Pixel Focus Guide
The Super 35mm single sensor digital cine camera has brought wonderful creativity to many
genres of television program production, television commercial production, and theatrical motion
picture production. The cinematographer is an integral part of the creative aspirations of
directors and directors of photography in their intimate tactile manual interface with the lens
focus control. But, a perennial challenge underlies shooting with such cameras – namely, the
singular challenge of ensuring truly sharp focus on a chosen subject within a given scene.
Electronic viewfinders are still limited in their resolution (especially when shooting in 4K), and
the desire for very shallow depths of field for certain scenes can compound the challenge.
In the new C300 Mark II, Canon is introducing to the industry an empowerment to the manual
focus control action that offers an innovative solution to the dilemma of uncertainty in focus
accuracy. The CMOS image sensor developed by Canon deploys two individual photodiodes
within each and every photosite of that 4K array. The microlens centered above each photosite
directs the light sample separately onto each photodiode in the manner shown in Figure 12.
This provides a dual signal data output having a phase difference that is dependent upon the
degree of defocusing at each photosite location. The two signals then undergo powerful
arithmetic processing that ultimately produces a unique unambiguous focus guiding indicator to
the camera viewfinder.
Figure 12 Focus Guide is a control loop that couples the manual focusing action to an indicating
guide in the viewfinder – created from the Dual Pixel data from the CMOS image sensor – that
unambiguously directs the cinematographer as to which direction to rotate that Focus Controller
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