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... Not sure yet... let's see... - ------------------------ Depth of field is the range in which the circles of confusion are small enough for something in the image to seem sharp. I'll buy that. - ------------------------ 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. OK - --------------------- The smaller the film/sensor, the greater the magnification needed to make, for example, an 8x10 print. Well, I gueess that is one way to look at it... the "negative" is smaller. so to get the same print size, the enlargement magnification would be greater - -------------------------- 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? I don't think it is relevant. But I could be wrong ..... - -------------------------------------------------------- It is possible that with a larger print, you just increase the viewing distance.) For what purpose? - ------------------------------------- For a smaller sensor, a shorter lens is needed for the same field of view. True - --------------------------------------- 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. May be why I was not so sure in previous comment.... - ------------------------------------------- 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? I dropped out of math when they started talking about 5 dimensions..... - -------------------------------- What is it you are trying to get at? be less scientific, more subjective..... Frank - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html