Steve Hodges <shodges@wantree.com.au> writes: > chandler wrote: > > > > The term "magnification" usually means the (physical) image size divided > > by the object size. > > Well, actually a 2x magnified object appears 4 times larger :-) Yes, of course I mean "linear size". > > Unfortunately, they then for example use "macro" to > > mean 1:1 or bigger in a particular format, typically 35mm; this isn't > > really very sensible, > > It's extraordinarily sensible. Macro starts when the image size equals > the object size. How simple is that? The calculations can then ignore > film size. Beautiful. Yes, it may be very sensible in terms of exposure calculations, or whatnot, but it's not much help in terms of describing the scale of an image, as in a competition class for "A butterfly at 1:1 magnification." Different film/sensor sizes yield totally different scales of image. Brian Chandler ---------------- geo://Sano.Japan.Planet_3 http://imaginatorium.org/
