Macro photography is the somewhat confusing name for closeup photography. Just as the human eye can only focus up to a certain distance (a distance which moves alarmingly further away with age), not all lenses can focus as closely as others. Most lenses are designed to focus up to a metre or two with long telephoto lenses having much longer minimum focussing distances than that.

Now this obviously isn’t going to help you if you want to take a super closeup of a small flower - you need a much shorter minimum focussing distance. Basically you want to be able to fill the frame with your small subject. And another concept comes in - the magnification factor. Traditionally, true macro photography refers to 1:1 photography and smaller. In other words, a lens with 1:1 magnification is able to image an area as small as the exact size of the image format in question. In the case of 35mm film this means an area of 24x36mm in size. Sometimes magnification is written as a decimal factor, such as 0.25x or 1.0x.

Unfortunately, lens manufacturers tend to throw around the word “macro” with cheerful abandon as a marketing gimmick. The fact a lens has MACRO printed on it basically means nothing, and you have to look closely at the lens specs. If a lens can do 1:1 or 1:2 photography then it’s a real macro lens, optimized for closeup photography. It may also be designed with a flat field so it can be used to take photographs of flat objects like stamps without focus problems. Lenses that can only reach 1:4 or whatever can’t take really close-up pictures.

True macro lenses are generally of much higher optical quality than ordinary lenses and usually cost more. They are also usually optimized to take photographs of small flat objects with even focus across the surface - flat field. They’re still a good buy if you don’t do a lot of macro photography, however. You can always use them for regular photography as well - they just have the bonus that they can focus much closer than ordinary lenses can.