Linhof Lensboards | Three different sizes of Linhof lensboar… | Flickr
Zone VI 6 4x5 camera Flat Lens Board all Sizes Copal Compu Ilex 00 0 1 2 3 4 | eBay
Comfort Technika 45 lensboard | Linhof
Amazon.com: Arducam Lens Board OV5647 Sensor for Raspberry Pi Camera, Adjustable and Interchangeable Lens M12 Module, Focus and Angle Enhancement for Raspberry Pi 4/3/3 B+ : Electronics
film - What is the necessary recess on an enlarger lens board? - Photography Stack Exchange