Let's say we are shooting a 3-dimensional subject like a flower, using 4x5 film, at close range, at exactly 1:1. Let's say we are using a camera with lots of bellows draw. To make a 1:1 image with a 150mm lens, we need 300mm bellows extension. To make a 1:1 image with a 300mm lens, we need 600mm bellows extension. I presume we can take the picture from twice as far away with the 300 mm lens, as we can with the 150mm lens.
Even though the 150mm lens gives greater depth of field (presumng the same f/tsop used in both cases), we have to get in 2x closer to fill the frame. The closer we get, the more critical becomes depth of field, because the distances between parts of the subject are relatively greater.
Does that closeness defray, proportionately, the depth of field gained by using the shorter lens ?
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