Hardware.

As a software developer, you don't see much of the hardware you're programing for. Everything is done in simulated hardware.
Today I got to test a piece of the software I wrote on the real hardware we're selling.
Ofcourse there are always those issues like the measurements are way off... "oh let's fasten that part", or "is this really a 2.0 mm stylus, like I entered in the software?"

These are some of the parts our machines use for measurements (the caliper is mine ofcourse).

I used the ring-flash I bought yesterday, which is causing these particular shadows.