I am sure its a good lens. Looking at the lens diagram, the plastic element is the front or exit element and that indeed is the largest element area wise and I think the one that would result in the greatest cost savings. How that one piece would affect the image compared to the complex glass multi element exit group on the 1000ES, as in the lens diagram for the 1000ES, I really don't know. In general, the exit glass group is the least critical in the 500/600 (it is a single element group) and I suspect it will affect the area of the sweet spot and sharpness and CA as one migrates from the sweet spot. And that is the engineer in me.
post #331 of 1083
9/14/13 at 6:12pm