Michael H. Cothran |
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Lisa,
FYI - Many, many zoom lenses have "macro" modes, or even call themselves "macro lenses" or "macro zooms", but these ARE NOT true macro lenses. Many will achieve magnification ratios in the 1:4 area, but often with less than desirable quality.
Current true "macro or micro lenses", as Nikon calls theirs, are ALL single focal length lenses, and will all focus to 1:1 (which is life size), while older manual focus versions will still go to 1:2. Your salesman is correct in that at either of these closeup ranges, you could fill the frame with a postage stamp.There are THREE important differences between true macros as opposed to "macro" zooms:
1. True macros focus on a FLAT field, which is why they are so good for postage stamps, whereas, all other lenses have a CURVED field of focus (not too many photographers are even aware of this!). 2. True macros are all designed and engineered to perform their best at ratios around 1:10, whereas all other lenses are designed to perform their best at longer distances, usually about 1:50. 3. True macro lenses have always represented the cream-of-the-crop in a manufacturer's lens lineup. Thus, they are never cheap, but always good. Most major camera manufacturers and independent lens makers offer three true macro versions -
a normal length - 50-60mm, a short tele version - 90-105mm, and a long tele version - 180-200mm. The exact focal length depends on the maker. For instance, Nikon's are 60, 105, and 200. Canon's are 50, 100, and 180. Now, before someone corrects me, let me also say that over the decades there have been a couple of actual, true macro zooms manufactured. They have never been up to snuff with the fixed macros, and have never gained a lot of popularity. The two that come to mind are the Vivitar 90-180 macro zoom of the 1970's era, and most recently, Nikon's own 70-180 macro zoom. One substitutes some image quality in these macro zooms for versatility.
Hope this helps.
Michael H. Cothran
www.mhcphoto.net
June 07, 2005
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