Definition: Macro photography is taking extremely close-up images of subjects. The technically correct definition would be to take an image at a 1:1 ratio but, in general usage, the term has come to mean any close-up photography.
Macro capable photography lenses are marked with magnification ratios such as 1:1 or 1:5. A 1:1 ratio means that the image would be the same size on film (negative) as in real life. A 1:5 ratio would mean that the subject would be 1/5 the size on film as it is in real life. Due to the small size of 35mm negatives and digital sensors, a 1:5 ratio is nearly life size when printed onto 4"x6" paper.
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