Greg Derylo

Pi pole pinhole

You’re viewing one of the Fermilab pi poles as it stood throughout a five-month-long period from July to November — taken with a pinhole camera.

This image of the Proton Pagoda is a five-month-long exposure taken with a pinhole camera was made from an aluminum can and a sheet of photo paper. It was taken from June to November and shows the sun’s path every day in that period.

Greg Derylo took this photo using a pinhole camera fashioned from an aluminum can and a sheet of photo paper. Mounted on a fence outside Lab B facing the Fermilab bubble chamber, the camera took a 13-week-long exposure that shows the sun’s path every clear day over that period.

What is it? It’s the precision measuring head of a Zeiss coordinate measuring machine in Lab A. Coordinate measuring machines use probes, such as the one pictured above, to measure objects’ geometries. For example, you can place the probe inside a cylinder to measure its diameter and out-of-roundness.