Anybody find these big focusing errors Ctein mentions in his Post Exposure writings? I'm thinking about running the simple test he explains, just for the hell of it, but I'm wondering why nobody else ever talks about this phenomenon, or why even in workshops with some of photography's big names, I've never heard about it? Based on the way Ctein describes it (with focus for an 8x10 print potentially being off by something like 15mm (!!!)), that would be horrible. And it seems like you can't avoid it even with a high quality APO enlarging lens. Strange, and disturbing.