Quote Originally Posted by David A. Goldfarb
I've never used the FD 100/4 Macro, but it is the only Heliar type in the FD line, so how bad could it be?
So David, et al.,

ignorant question -- I googled for a half hour or so and couldn't find a more lengthy definition, but someone mentioned in passing that Heliar = five element. Pardon my ignorance, but is that what Heliar means, and if so, the value is because the fewer surfaces the light passes through the better, or at least the less margin for error?