On Thu, 27 Feb 2003, J. C. O'Connell wrote: > > Not true. Using a film camera, take a picture of a person with a > > telephoto lens so that all you can see is their head and shoulders. Then > > put a wide angle lens on, and walk closer to the subject until you can see > > just their head and shoulders. Now your subject is the same size as it > > was with the telephoto lens, but you have much more DOF. > > This is false. If the reproduction ratio remains the same like > youre describing above the DOF is also the same for > a given f-stop, regardless of focal length...
...only if the photographer stays in the same place. If you stand in the same place and take shots with different focal lengths, the DOF is the same (you're essentially just cropping). But if you *change position* (like I said above) to keep the subject size the same while using a different focal length, then your DOF will change, too. DOF depends on focal length and aperture, as you say, but also on subject distance. chris
