Sightline

A housing for a compact thermal spotting scope: a machined tube that holds the lens stack to a few microns across a wide temperature range, wrapped in a moulded grip that never touches the optical path. Focus is a single knurled ring with a hard stop at each end.

The hard part is what you can’t see: the athermal spacer stack that keeps the image sharp from a cold morning to a hot dashboard. The outside is just a handle for it.