This is a Lensboard for the Leitz Hektor 150mm f2.5 Lens, fitting in a Graflex Speed Graphic 4x5 Camera. Lens-Socket Diameter 60mm.
My lens clamps perfect tightly in the hole, so that it not slips out the socket easily. I use it without, but if you prefere some additional security, i recommend to drill a hole in the printed socket and clamp the lens with an additional screw.
The Lensboard must be removed when closing the camera!
Article and Description: http://www.carsten-nichte.de/en/a-lensboard-for-the-graflex-4x5/
Feel free to write a comment. Ich like to hear your feedback and see your builds :-)
Photography and other creative stuff :-)