Archived posting to the Leica Users Group, 2000/04/02
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]I think you mean image size rather than object size... Still, remember that depth of field is not symmetrical around the point of focus. Usually 2/3 is beyond the focus and only 1/3 in front of it. That's why we can focus on the eyes and get both the nose and hair OK. Then again, if you use your formula, you don't have to remember hard stuff like that. Example: Taking a close up picture of a cow in dim light: Cow = 2000 mm (79") long Focal Distance = 1000 mm (39") Aperture = f2 DOF/2 = 2000/2 x 1000 = 1,000,000 mm = 3281 feet So DOF = 6562 feet 2000 feet in front and 4000 feet behind. Hmm... Yes. That ought to do it. Of course your results may differ with species, magnification, and whether the camera has a red dot. Mike Quinn Mitch Alland wrote: > For the other cases, in which the smallest object to be recorded is smaller > than the lens aperture, he gives a simple formula to calcute the DOF. (Size of > object/lens aperature size x focal distance gives 1/2 the DOF).