181mm telephoto pinhole for canon EOS R100.
Test image from across the house.
This 'lens' has a focal length of 181mm and a pinhole diameter
of ~0.59mm. It's made using 2 inch diameter black PVC pipe,
a PVC cap, Aluminum from a Quirk can (0.2mm thick), gaffer tape,
and a Canon body cap.
I'll update with more photos here as I take them.