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Matching lenses from each maker's lineup, plus some classic medium and large format lenses. Email me if something is wrong or missing.
Interactive side-by-side simulation at the same subject size: see how 90mm APS-C and 135mm full frame change camera distance, perspective, depth of field and background blur.
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Matching lenses from each maker's lineup, plus some classic medium and large format lenses. Email me if something is wrong or missing.
Both images show the same portrait at the same size. Both cameras stand at almost the same distance, because 90mm APS-C and 135mm full frame have a similar field of view. From closer in, 135mm full frame shows more of the room around the person. 90mm APS-C has a narrower field of view, so the background looks larger and closer and is easier to simplify.
Start at f/2 on the left and f/2.8 on the right. Then try f/1.8 vs f/1.8, or open both to f/2 and f/1.8. Match depth of field sets the right-hand aperture so the background is as blurred as on the left. The smaller APS-C sensor needs a wider aperture to reach the same background blur as full frame.
At the face framing, 90mm APS-C stands 2.2 m from the subject. At f/2 the sharp zone runs from 2.2 m to 2.2 m. 135mm full frame stands 2.2 m away, and at f/2.8 the sharp zone runs from 2.1 m to 2.2 m.
In the face framing, 90mm APS-C stands 2.2 m from the subject and 135mm full frame stands 2.2 m. Both cameras stand at almost the same distance, because 90mm APS-C and 135mm full frame have a similar field of view.
At the same framing, a distant background blurs in proportion to the aperture opening, focal length divided by f-number. 90mm APS-C at f/2 opens 45.0 mm and 135mm full frame at f/2.8 opens 48.2 mm, so both blur it about the same. Close behind the person, the focal length matters less and the f-number more.
Hardly. Both frame the face from almost the same distance, so perspective and background size match. What changes is how much the background blurs at a given f-number.
Also see: depth of field, bokeh, crop factor, lens compression.