Archived posting to the Leica Users Group, 2004/02/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Confusion and possible misinformation follows... (I am trying to think through this as I write.) Please correct as needed... Depth of field is the range in which the circles of confusion are small enough for something in the image to seem sharp. A 35mm lens set to a given f-stop and focused at a given distance will produce the same pattern of circles, regardless of the size of the film/sensor. The smaller the film/sensor, the greater the magnification needed to make, for example, an 8x10 print. Greater the magnification of the image yields greater the magnification of the circles of confusion which should give shallower apparent depth of field. (Is this true? It is possible that with a larger print, you just increase the viewing distance.) For a smaller sensor, a shorter lens is needed for the same field of view. It seems like the greater enlargement needed for the small sensor should partially offset the effect of the wider lens needed for that small sensor. It is quite possible that one of the effects is linear and the other is quadratic (or something else). Is there someone on the list that can co the math? C.R. Marshall - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html