Originally posted by Uluru Gosh,
I'm not sure what people are talking about here? You are turning things upside down.
Using the same focal length(*) and the same aperture, and a subject at the same distance, an APS-C camera will produce a thinner DoF than an FF camera....
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You're describing completely different images, though, with different field of view.
What folks typically do when they move between formats and still want to shoot the same types of things is change the focal lengths used. If you don't do that, your images change radically and become something you don't want. Probably the most typical example is 'normal' - on FF, you shoot a fast-50, on aps-c, you shoot a (hopefully) fast 35. (or, you simply adjust your zoom FL to fit the subject.) Those are very 'workhorse' focal lengths, especially for indoor shooting.
And what you'll find is that although the FOV is the same between the two (50 on FF vs 35 on aps-c) the DOF is not, when using the same apertures. 50mm f/2.8 (FF) = 35mm f/1.8 (aps-c,) for example.
Anyone reading this who hasn't checked out of the discussion should cut/paste and save the bullet points from Bob Atkins below - these can be considered the
Cliff's Notes for DOF-format discussion:
• For an equivalent field of view, an APS-C crop sensor camera has at least 1.5x MORE depth of field that a 35mm full frame camera would have - when the focus distance is significantly less then the hyperfocal distance (but the 35mm format needs a lens with 1.5x the focal length to give the same view).
• Using the same lens on a APS-C crop sensor camera and a 35mm full frame body, the APS-C crop sensor camera image has 1.5x LESS depth of field than the 35mm image would have (but they would be different images of course since the field of view would be different)
• If you use the same lens on an APS-C crop sensor camera and a 35mm full frame body and crop the full frame 35mm image to give the same view as the APS-C crop image, the depth of field is IDENTICAL
• If you use the same lens on an APS-C crop sensor camera and a 35mm full frame body, then shoot from different distances so that the view is the same, the APS-C crop sensor camera image will have 1.5x MORE DOF then the full frame image.
• Close to the hyperfocal distance, the APS-C crop sensor camera has a much more than 1.5x the DOF of a 35mm full frame camera. The hyperfocal distance of an APS-C crop sensor camera is 1.5x less than that of a 35mm full frame camera when used with a lens giving the same field of view.
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