Originally Posted by
Harold_4074
Okay, compose an 8x10 head shot with your 360 f/6.5, stop your 300mm f/2.8 down to f/6.5, and make the same picture full-frame in the DSLR. I expect that the angle subtended by the DSLR lens will be considerably smaller than that subtended by the LF lens, so the perspective and illumination quality will not be the same. I think that this is close to what the text I remember was describing, since at the time the book was written the corresponding comparison might have been between a 6x6 TLR or a 35mm SLR and something like the 405mm Kodak Portrait. If the authors were correct, the format does matter because the other imaging parameters are not completely independent of the film (or, today, sensor) size.
I admit to having phrased the original argument (dating from probably the 1960s) to rule out things like multiple digital images being merged or assembled to give the effect of a large front element without perspective problems; this is partly because I spent some time trying to figure out how to do exactly that, and concluded that only a mannikin head (are you reading, this, Randy Moe?) would have the patience and ability to hold still long enough. I gave this up when I realized that translating the small-format lens radially takes the optical axis with it, so that combining the array of images would give a third type of image, not a simulation of either the large, fast SLR or the large, slow LF lenses.
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