A friend and fellow photographer, Scott Simons, recently put on a presentation discussing early morning photography. During that presentation he was asked why use one macro lens over another. It was a good question and one that I will answer here for you today. This is for the most part, specific to people shooting with SLR type camera’s with interchangeable lenses. While other camera’s may have the ability to use screw on or accessory lenses in conjunction with the existing lens, I am not talking about that today.
First, why a macro lens. Macro lenses enable the photographer to photograph small subjects in great detail capturing up to life size reproductions the subject. 1:1 life size simply means that the images appears the same size on the film plane (or digital sensor) as it is in real life. Macro lenses are typically very sharp which help in capture fine detail of small subjects. They also allow for necessary, precise manual focusing.
For 35 mm digital photography, most macro lenses will be somewhere within the following set of focal ranges: 50mm, 60mm, 90mm, 100mm, 105mm, 150mm, 180mm and 200mm. Of course, not all manufacturers make all focal lengths but most will make three of them. The 50 and 60 are generally considered wide angle macro lenses, the 90, 100 and 105 normal macros and 150, 180 and 200 telephoto macro lenses. So what is the difference?
The difference between the focal lengths of any lens is field of view. A 18mm wide angle lens has a greater field of view than a 200mm telephoto. The same is the case with macro lenses. This is important because the wider the field of view, the more background will be a factor in your image. Generally you want to sufficiently blur the background to help bring emphasis to the subject but not necessarily always.
For comparison, I will talk about the lenses as used when photographing a subject at 1:1 (or life-size) that does not occupy the entire frame: a subject with a background.
A wide angle macro lens will incorporate more of the background than a medium or telephoto macro. At the same time, the working distance (the distance between the camera and subject) will be closer when working with a wide angle macro than with an medium focal length macro or telephoto.
Working distance is a factor because the more distance between the camera and the subject, the greater ability you as a photographer will have to use light modifiers to manipulate your image. Another advantage is that when your subject can move such as butterfly, you can help prevent them from being too skittish and walking away on you by staying as far back as possible.
Where is the advantage? Most people I know will say that the advantage lies with the longer focal length macro lenses. They narrow field of view and a greater working distance from your subject typically help to create fantastic images. The drawback is that longer focal length macro lenses cost significantly more money any are heavier. If you need to carry your equipment long distances, weight may be a concern.
If you are interested in macro photography, you can start with some less expensive alternatives. Extension tubes allow you focus closer than a given lens normally allows and close up diopters may help you as well. Next week I will talk a little bit about these and other options.
For a look at some of my own macro photography, visit http://potd.chrisempey.com/archives/macro/
Until next time, happy shooting.