I cannot afford to buy a macro lens right now, but in a book on close-up photography I read that a supplementary close-up filter, such as the Canon 500D, is a useful alternative. Apparently, it forces any lens to focus much closer than usual for true macro photos. Do you recommend this for owners of digital SLRs?
Resembling a filter with magnifying glass, Canon’s Close-up Lens 500D would be a useful accessory with a tele-zoom lens, whether used with a DSLR or a compact- system camera, Jean. And, it’s suitable for any brand of camera/lens, not only Canon products. It’s specifically optimized for use with telephoto zooms such as 55-200 mm or 70-300 mm, and it does allow for much closer focusing than the lens would normally provide. The higher magnification can be useful for frame-filling photos of miniscule subjects. (The longer the focal length of the lens used, the greater the magnification will be.)
You can find close-up “filters” of other brands for much lower prices, and they work in the same manner. While the Canon 500D is more expensive, it’s the one I prefer because it can retain optimal image quality. You may also be able to find a used Nikon 5T, a similar product, also of very high quality in 62-mm size only; it was discontinued a few years ago. The Canon accessory features an “achromatic” optical element to minimize degradation of image quality. For the best results, use a high-grade tele-zoom lens with low-dispersion elements and shoot at a small aperture such as f/11 to f/16.
The 500D is manufactured in 52-mm, 58-mm, 72-mm and 77-mm sizes, but most retailers list only one or two of those. (They may be able to order one of the other sizes on request.) If none of those sizes is suitable for your lens, or if you can find only a larger size than you need, there’s a simple solution. Let’s say your lens accepts 62-mm size filters. In that case, buy the 72-mm accessory (about $250) and a “step-down” 72-62-mm adapter (under $15). The combination will work well, but you will not be able to mount the lens hood, so be careful when taking photos in bright side lighting where flare can create problems.
As you might expect, a true macro lens—with a mechanism and optical elements that provide excellent quality in close focusing—is the ideal option for extreme close-up photography. This type of lens provides greater sharpness in the corners of an image than a tele-zoom with a supplementary close-up lens; the difference is most obvious at the corners of an image and in photos made at a wider aperture such as f/5.6 to f/8. However, as you have hinted, the Close-up Lens 500D (or a used Nikon 5T) is the best available alternative for those who simply cannot justify buying a macro lens.