If you've been following along (or checked the equipment list), you might have noticed that I now own four different macro lenses. You might also wonder why one would need that many different specialty lenses.

The answer is that each one provides a different focal length (35mm, 65mm, 100mm, and 180mm). While each one provides a different working distance to the subject, that causes different perspective, and also a different field of view. The field of view is basically the amount of the scene that is in the frame. Perspective can be thought of as the relationship of foreground elements to background elements.

	35mm
	100mm

Technical Data: Canon EOS 7D, Tokina AT-X M35 Pro DX AF 35mm f/2.8 Macro 1:1 and Canon EF 100mm f/2.8L Macro IS USM respectively, 1/30 and 1/80 sec respectively at f/2.8. ISO 100. RAW processing in Adobe Camera Raw

In this case, I kept my foreground subject almost identical in the frame, but if you look at the background, you can definitely tell a huge difference. Here, I used a wide aperture to get a shallow depth of field, so the background is pretty well blurred and full of soft bokeh.

However, if you look at the shapes of the background, you can definitely identify a couple major differences. First, the 100mm shot has a much less cluttered background because it has a much smaller field of view. Additionally, the perspective causes the background elements to appear much larger in the frame (and thus making them seem closer).

- Bill