sebboh wrote:
if there is one thing that repeated threads about 3D in the alt forum have proven, it's that the term 3D doesn't have any particular meaning.
That's for sure!
If you take photographs that various people regard as having the so-called "3D" effect and then ask what it is about the images that produces this response, you'll find that a whole bunch of factors tend to be connected to their reaction. They might include any of the following:
1. A wide angle lens that produces a strong foreground/background contrast. (See the classic "near/far" landscape composition.)
2. Use of narrow DOF and background (and sometimes foreground) blur to set off the primary subject. (I refer to this as subjective sharpness — the subject may not be objectively particularly sharp, but it appears to be by comparison to other elements in the composition.)
3. Skillful use of lighting to highlight (typically) primary subjects and de-emphasize secondary subjects. (For example, beautiful light may fall on the primary subject, while lower light levels may appear on background elements.)
4. Partially related to the above, use of contrast in a variety of ways. These include (as mentioned above) illumination contrasts between lighter primary subjects and darker (sometimes much darker) background elements. Another technique may be to have a greater range of values (more contrast) in the primary subject with less in the background subjects. (The classic "atmospheric recession" effect in some landscape work can be an example.)
5. Intelligent use of color can enhance the effect, and in several ways. A primary subject of one predominant color may stand out against a background the features a different color, and perhaps a complementary one. Or the foreground subject may have more saturated color while the background colors may be more muted.
6. Composition is also significant. A composition that incorporates clearly separate elements at different distances invites us to pay more attention to the actual depth of the scene, especially if the elements do not interfere with one another.
7. Post-Processing work that selectively emphasizes and deemphasizes elements of the scene can focus attention on those that are primary and make them "pop" out of the background detail.
8. When photographing human subjects, a variety of factors can affect the result — the direction of the gaze, the angle of the subject's body, the quality of the light, and much more.
I'm convinced that when we consider all of the things in photographs that may produce the effects that some call "3D," we find that very, very little of it is due to the specific brand and model of lens.
YMMV,
Dan