After a 20-year absence, Canon appears to be dusting off its love-it-or-hate-it Eye Controlled Focus system – a technology that skipped the digital age entirely, as it hasn't been used in any DSLR or mirrorless cameras.
Previously used in Canon's film cameras, the tech enables you to move your focus point simply by looking at it – the camera detects where your eye is looking and selects the point accordingly.
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The last time we saw Eye Controlled Focus was in the Canon EOS-3, which boasted 45 AF points (a dramatic uptick from the 5 AF points of the Canon EOS-5 / A2e and the 7 AF points of the Canon EOS 30 / Elan 7e). It was never made clear why the tech didn't translate to the digital era, though some suggested that the sheer number of AF points could be the issue (and something like the Canon EOS R5 has a staggering 5,940 AF positions).
Still, Canon first resurrected the technology with a fresh patent back in 2019, in the wake of the original Canon EOS R. That registration, spotted by Canon News, described an infrared LED working in conjunction with an algorithm to perform line-of-sight detection:
"The line-of-sight direction is detected by a predetermined algorithm, which will be described later, from the positional relationship between the eyeball imaged on the eyeball image sensor and the corneal reflection of the light sources".
Now the technology has been revisited, with a fresh patent unearthed by Northlight Images. Subject detection is now part of the equation (so the aforementioned algorithm might even incorporate Canon's Deep Learning AF) and also it can also recognize the user's iris and store past behaviors. It describes the process thus:
"An image capture apparatus detects a subject in a captured image. The image capture apparatus further recognizes its user based on an eyeball image of the user. The image capture apparatus then selects a main subject area from among the detected subject areas, based on information regarding subjects captured in the past and stored being associated with the recognized user."
Of course, as you might remember if you ever used the old Canon SLRs, the original system was pretty hit-or-miss. It either worked perfectly or it was a complete disaster, depending entirely on the user – and particularly whether they wore glasses, which always seemed to interfere with the system – and this is likely the reason that it didn't make it past the SLR age.
So why is Canon retreading old ground now, two decades on? It's likely that modern detection technology has finally caught up with the original bright idea. The original patent identifies the objective: "To improve user convenience by automating a calibration operation of a gaze position while accurately recognizing a subject in a subject recognition device having a gaze detection function."
Indeed, Canon described the EOS-3's Eye Controlled Focus as being "almost twice as fast and more precise" – and an AF system that moves at the speed of sight is certainly faster than using a joystick or tapping a touchscreen, so this could be a genuine game-changer if it ever comes to pass…