There are two types of photographer: those who utilize their lens cap, and those that don’t. Canon now seems set to make this a thing of the past, as it has patented a barndoor-style lens cap design that folds open when shooting, and shuts to protect the lens when not in use.
As per Japanese Patent Application 2019-113645, the innovative new lens cap design is said to be designed with an aim to ending the attachment and removal of lens caps for good. The patent reads:
The present invention works as a lens hood function at the time of shooting and as a lens protection function at the time of non-shooting, thus eliminating the need for lens cap attachment/removal and barrier opening/closing operations.
It’s early days yet, but the idea would mean never losing a lens cap again, given that this design would be permanently affixed to the lens. However, whether it’s quite as air-tight and can prevent dust, dirt, and moisture from getting through remains to be seen. There’s also the concern that the design would eliminate the chance of using attachable filters in front of the camera.
The designs featured in the patent application also appear to signify that the proposed barndoor-style lens cap would only work with lenses that have extending barrels. It seems internal zoom/focus lenses wouldn’t work with this design.