This is a shot I took of one of my aeronautical charts. I used it for the map material.
step 2 of 5
To model the screw head a cube with mesh smooth modifier 2 iterations applied. Adjustments to the vertices made.
step 3 of 5
The lens assembly consists of tubes and a cylinder. These were scaled and put together with exception of the screws. The assembly (without screws) was modified with bend modifier on the "X" and "Y" axis as a group.
step 4 of 5
The mask (rubber) portion is a geosphere with soft selection mods to its vertices. The canisters are cylinders adjustments to edges an mesh smooth modifier. all textures are 3d max mental ray materials. (metal, with color adjustments and rubber material)
step 5 of 5
The map is a plane with corrections made to vertices. My photo used as a material.