Macro Digital Photography

The macro photography is the recording of objects or details of a reduced size. Normally a lens doesn't let us get close to an object and photograph it's minimal details: the focal mechanism has a minimal focal distance which depends on the design of the lens. For example, a 50 mm lens at a minimal focus distance of 50 cm lets us register a scene whose sides are nine times greater than those of the 35 mm image (21.6 x 32.4 cm in a 24 x 36 mm image, relation 9:1). This relation doesn't correspond with what for our vision is "seeing with detail", and excludes photography of smaller objects. A macro lens has a

focal mechanism that les us get close until achieving a relation of 2:1 as maximum. Nonetheless, any lens can be used for microphotography, with variable lenses .

The general formula of linear enlargement (A) is: A = f / p - f, were f is the focal length and p is the focus length. When p is less than 2f we obtain an image larger than the scene. The same goes for the other distances, we have the possibility of choosing between long and short focal lengths. Long lengths cover a smaller angle and let us get a more far away perspective, but require a greater extension for the same increase of a lens of short focal placed closer and who's perspective is associated with a larger angle of vision and greater depth of field.