Archived posting to the Leica Users Group, 2001/08/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Olivier writes: > but for this kind of focus, the result is only > an acceptional of sharpness not perfectly sharp > please correct me. You are quite correct, and your concern is very reasonable. Using zone focusing works _IF_ the final image will be viewed at a "normal" viewing distance and _IF_ the full frame will be used (no cropping). However, if you crop the image and enlarge it, or if you view the image from a distance closer than the "normal" distance, the depth of field figures used on the lens are no longer valid. DOF drops as you get closer to an image, and something that looks in focus for a full frame from a normal distance may look very blurry when viewed closely or when cropped and enlarged. This is why it is always best to focus precisely on the subject you actually want to have in focus, if possible, and if you have time. The only exception is when you have different elements in the image at different distances and you want them all to be at least moderately well focused--then you have to compromise. Nevertheless, for photography that is not critical for sharpness, such as street photography and photojournalism, the speed advantage of zone focusing can be considerable. I still try to avoid it, myself, as long as I have time to focus for real.