Monday, November 16, 2009

Model Photography - The Most Problem With Model Photography

The most problem with model photography is depth of field which is accentuated by the conditions in which these subjects are shot. As we have seen previously, the depth of field increases when the aperture is reduced (f-stop is increased). For a given objective, the opening is limited by mechanical and optical, and hardly goes beyond f: 22, in most cases.

The answer to this problem is to tinker a little, to get smaller openings (which, incidentally, will lead to exposure times even larger) as this type of equipment is not commercially available.
In practice, it is considered that F: 100 gives rise almost infinite depth of field (a few centimeters to infinity). This opening corresponds to an aperture of 0.5 mm diameter hole for a lens of 50mm focal length, which is almost the smallest hole that can be done without too much difficulty (since, as explained below, achieving this hole is not so simple). We returned the camera to our grandparents, the pinhole, which was founded on the principle but does not include lens.

With smaller apertures, is the phenomenon of diffraction of light from the hole edge effect ". The thicker the edge of the hole, the most important phenomenon. Also, over the hole, the greater the effect. The effect of this is to make the picture all fuzzy, which does not help much because it is exactly the opposite of what we seek. So What's It All About?

The first step is to get a lens that mounts on the device you own, preferably a lens used and inexpensive, as we shall abuse. Prefer a prime lens (with focal length 50 mm - is the best) because they are much easier to remove than a zoom. Make sure the rear lens group (the group behind the lens, between the diaphragm and the mounting ring) is easily removable as a whole and does not require removing the lenses one by one.

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