If you want top notch optical and build quality along with very capable macro capability, the you have to consider the Zeiss 50mm f/2.0 makro. Just keep in mind that you're going to pay top dollar for a manual focus lens, but at least it has a really smooth and precise focus ring and focus confirmation - so if you don't have the best eyesight, then you'll still have a fighting chance of capturing your shot in focus.

Great Price on the Zeiss 50mm f/2.0 Makro Plannar from B&H Here

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