Here's the wiki definition of macro photography. There's a classical definition of life size on the film plane, but it also mentions a more recent definition of life size on a standard size print.
Also bear in mind that life size on the film plane will mean the object looks smaller on a file produced by full frame digital camera, as opposed to APS-C, although it will have actually been reproduced as the same size at the film plane.
This possibly brings up the issue of output - I can make a similar dimensioned jpeg from a full frame and from an APS-C. However, the object will be smaller in the one taken by the full frame.
Just to confuse things further, most still life/product shots taken with an 8" x 10" studio camera are probably macro shots when you apply the classical definition!
I think many people now look upon macro as meaning close up. I'd personally go for the classical definition (life size on film plane), but there are no standards bodies for this sort of thing (as there are in engineering). So it's whatever you want it to be. ![Smile [:)]](/emoticons/emotion-1.gif)
Chris Seary
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