variation

There is No Such Thing as a Perfect Lens

I get asked a couple of questions every time I publish a graph showing Imatest results for multiple copies of lenses like the one below. Most people understand that some copy-to-copy variation is inevitable in the manufacturing process. Most are surprised, though, at how large the sample variation seems to be. Heck, I was surprised at how large the sample variation was when I started doing this kind of testing.