When is 50mm NOT 50mm?

Field of view on the main subject will be the same, but if you move your feet you changed perspective. What is included in the background will be less.

The only way to get similar images between a full frame and APS-C camera is to use the "equivalent" lens.

i.e. 50mm f/2.8 on full frame and 35mm f/1.8 on APS-C would give you the same images. Depth of field, framing, etc.

I never like that saying "zoom with your feet" as it is entirely incorrect. You change perspective with your feet, and zoom by changing lenses, cropping later, shooting a panorama to get wider, or turning the zoom ring on a zoom lens.

Eric

--
I never saw an ugly thing in my life: for let the form of an object
be what it may - light, shade, and perspective will always make it
beautiful. - John Constable (quote)
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