First Canon introduced CMOS dual pixel phase-detection autofocus on its EOS 70D Digital SLR camera. Then it was announced as an upgrade for the C100. Now, continuous autofocus will be available as an upgrade on the EOS C300 with Canon autofocus lenses.
Dual Pixel CMOS AF works like this. All the available imaging pixels work both for imaging and phase-detection at the same time. Each pixel is made up of two photodiodes whose outputs are continuously compared. If there’s a phase difference, circuitry smoothly corrects to keep the image in focus. Of course, you need to use a Canon autofocus lens in auto mode, and tracking is done in the center of the frame. (20% of vertical and 25% of horizontal area.) This can be helpful when operating as a one-person band, running and gunning, for documentaries and probably wildlife wild hippo charging toward camera shots.
Canon says, “The Dual Pixel CMOS AF upgrade for the C300 camera supports continuous AF with all compatible Canon EF series lenses when shooting subjects positioned in the center of the imaging area. The technology involves complementary use of a contrast signal to achieve advanced autofocus stability that helps reduce the occurrence of loss of focus on a subject. Also included is an AF Lock which allows users to lock a focus point once AF is achieved and recompose the shot. Canon Dual Pixel CMOS AF also nearly doubles the speed of the EOS C300 Cinema camera’s One-Shot AF function, which enables a DP to focus on a subject located at the center of the screen with the push of a button, a feature that is currently supported on 104 Canon EF lens models.”
An upgraded C300 camera’s menu will have two options for “AF Mode” – One-Shot AF and Continuous Autofocus. The AF Lock can be assigned to one the camera’s buttons. Press the button to lock the focus, preventing the camera from refocusing, and then press it again when you want to return to continuous AF. It’s indicated by a white frame that turns gray when you push AF Lock.
The Dual Pixel CMOS AF feature upgrade for the EOS C300 Cinema camera will be made available to users through an authorized Canon service center for a cost of around $500. For more information: http://pro.usa.canon.com/EOSC300FeatureUpgrade
