Just added the 40mm pancake lens to my 6D + 24-105mm order, and it made me start wonder about this pancake design; why did Canon decide (or manage) to make a pancake lens now and not before, if it's so cheap to make yet quite good? Modern materials, computer aided design, or what...?
The wikipedia entry on pancake lenses is rather thin. Anyone know what focal lengths can be covered by pancake designs? 50mm?