Another toughie! Well in one sense not so much but in another maybe so.
Well let me say there are three or maybe even four general macro lenses:
the short focal length
the standard focal length
the long focal length
and
the telephoto lens
Now if you had to take ONLY one – a single macro lens – what would it be?
This is in part what makes it tough. My personal choice would be a long one! Why? Well there are few things the short lens can do that the long can not, maybe not quite a convenient but it can do them. However there are things the long can do the short simply can not!
So it would have to be a long one.. out of the long lenses that are available on the market the one that rises to the top again and again is the Nikon 200mm. Yes it is a stupid price, yes it is hard to find one and yes the used ones are still priced at crazy levels. But having said that it is worth every penny, that is if you are serious about photography and macrophotography in particular. This is a lens that was introduced in 1993, yes twenty five years ago, and yes still is sold by Nikon and still is the sharpest macro lens made by anybody. Why is it hard to find and why are used prices so high? Well Nikon has made maybe 500 a year on average or so – that is all! Now I agree there is not a huge demand for macro lenses and certainly not for the best macro lenses as many will live with the close focus zoom lenses they can buy at a bargain. Now it is important to note that those lenses are generally not even true macro lenses but are sold with that label by marketing teams – they are really only a close focus lens and nothing more.
The good thing is if you have a Canon or even a Sony you can get an adapter for the 200mm lens. Now I will agree it is not the fastest lens on the market at f/4, but it is the sharpest! You don’t need a fast lens for macrophotography – you need one that is as sharp as is possible and they have hit the nail on the head with this one.