Archived posting to the Leica Users Group, 2004/02/20
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> In practice that is true; you get greater 'effective' depth of field > with a small-sensor digicam than with a 35mm camera used at the same > aperture, but not nearly as great a depth of field as the very short > focal lengths and medium apertures would lead you to believe from > film experience. > Thanks. I think I've finally sorted all this stuff out in my mind. When you take a photo the reason that only one plane is in focus is because the light from the subject enters the camera not at a single point but rather a circular disk (the front of the lens). It is the diameter of this disk that will determine how fuzzy the background will be in the final print. The size of the negative or sensor and the magnification when enlarging don't matter as long as the end result is the same size. The same diameter disk (effective diameter of lens) represents a wider F stop (smaller f number) if the film or sensor size is larger. The term "aperature" in photography is often used synonymously with "f stop" but in astronomy a wide aperature telescope refers to a telescope with a large diameter lens rather than the focal ratio. So this can lead to confusion. PS Sorry Ted. I promise I'll stop now. - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html