I have heard and read this reference, many times. However...
Originally Posted by Ian Grant
having studied their websites, and all of the hard copy documentation I have from Rodenstock, Schneider and Nikon... I can't seem to find any statements (or data) indicating that f22 should be used for best overall balance with 5x4 lenses.
Schneider and Rodenstock do publish MTF data for their lenses, which clearly shows that f22 may in fact NOT be the best performing aperture for many of their lenses. Additionally, resolution testing of LF lenses (multiple samples) by Chris Perez and Kerry Thallman would also bare this out... see http://www.hevanet.com/cperez/testing.html.
I wonder where this bit of photolore originated?