The Pitfalls of the Focus-Recompose Technique
Digital Outback Photo casts doubt on a photographic technique that I use all the time - select the centre autfocus sensor on my camera, point it at the part of the photo that I want to be in focus, then reframe the image as required. Sounds like a familiar technique that yo use too? Well, at least in Jonathan Wienke’s opinion, this will cause the focus to fall behind the subject, instead of on it, which is pretty critical in situations where you have a very shallow depth of field available. Wienke’s suggests that we should all use the autofocus points that is nearest to the subject instead to achieve correct focus, which does mean having to faff about with changing the autofocus point…
“The error introduced by focus-recompose is greater with shorter camera-to-subject distances. If you are using a telephoto lens and focus-recompose on a football coach on the other side of the field, the error introduced would only be a small fraction of an inch and would be dwarfed by many other factors such as subject movement, photographer movement, and the fact that depth of field at 50+ yards distance is usually at least a few feet; even an inch of error in that case is about as significant as a fart in a tornado. But when shooting portraits at close range with wide apertures and the resulting narrow depth-of-field, it can really cause problems.”