Canon EF-S Protocol and Electronic Follow Focus

Awesome! Will come in handy…

Pick and Place

Two years ago, I spoke with a film maker who told me about the problem of manual focusing with the video enabled Canon DSLRs. As the focusing sensor works only when the camera’s mirror is down, when in video mode, with the mirror up, the camera switches into manual focusing mode, via the lens focusing ring. Several solutions exist on the market, but they mainly use mechanical links to deport the focus ring to more accessible place on the camera rig.

Some electronic solutions exist, but they use the Camera’s USB input and the focusing speed is quite low.

I decided to dig into the communication protocol between the camera body and the lens.

Canon EFS lenses are connected to the body via a 7 pin connector. Three for the power supply and four for a standard SPI serial interface (including digital ground).

Canon EF-S Connector Pinout

Then, I bought a lens extender to…

View original post 665 more words


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s