macro for protraits?

Dwig · Jul 19, 2009

Alpha said:
The perspective flattening in macro lenses is, by design, not much different than the flatting one would see in, say, an enlarging lens. Is the effect sometimes negligible due to sensor/film size? Yes. But it's there.

You are totally incorrect, at least as you've written it. I think you are using the term "perspective" incorrectly.

There is absolutely nothing about the design of a lens, including focal length, that has any direct effect on perspective. Anyone who says otherwise is ignorant of the physics involved. Perspective is controled soley by the relationship of the distances from the camera to the various objects in the image. The only impact focal length has is indirect; it influences the distance from which the photographers chooses to take the picture. Even then, its focal length relative to the image format and not the absolute focal length that has even that tenous impact on perspective.

To get proper perspective in a portrait the first step is to place the camera the correct distance from the subject (generally 7-10ft/2-3m). You then choose a lens that gives you the framing you want. The "magic" associated with certain "portrait" focal lengths is that when you use one and frame the image for a typical portrait you "accidentally" stand the proper distance from the subject and thus, as a result soley of the distance, get an image with a pleasing perspective.

What is special about the optical design of most macros is that they have much better field flatness (corner and edge focus are always in the same plane) when used at close distances and they generally have much lower rectilinear distortion (barrel or pincushion) than conventional lenses.