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by SpaceInvader 1324 days ago
> If you have an APS-C camera, which is quite common, then you want a ~32mm lens, and if you use M4/3 like I do, then you want a 25mm lens, to achieve this same effect.

It's not the same effect, far from it. It's different focal length, that will render different image.
2 comments
avalys 1324 days ago
A 50 mm lens on a full-frame sensor will render an equivalent perspective to a 32 mm lens on an APS-C sensor.

You can easily verify this by taking an 24-70 zoom lens on a full-frame sensor, taking one image at 50 mm in full-frame mode and another image at 32 mm in APS-C mode.

Depth of field and other optical properties may be different but the perspective will be the same.

The only thing that changes the rendering perspective is the physical location of the camera. If the camera does not move and you take a picture with the same field of view, the perspective will be identical regardless of the sensor size and focal length you used to achieve this.

The reason different focal lengths are imagined to produce different perspectives is because, implicitly, you need to stand a different distance from the subject to frame the same image at different focal lengths, and it's this difference in camera position that causes the change in perspective.

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SpaceInvader 1320 days ago
Actually perspective WILL BE different, angle of view is changing, not what the lens is rendering.
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wilsonjholmes 1324 days ago
Would you mind explaining or offering resources on understanding why it is different? I have a M43 camera as well, and I have always just halved the focal length and aperature I want a lens to be on my system to be a roughly equivalent match to the full frame performance I am trying to emulate.
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SpaceInvader 1320 days ago
I'll try :) Generally speaking focal length is a characteristics of a lens which does not change, if you use smaller sensor you're just "cropping" what given focal length would render. For example if you'd have, let's say 100mpix camera and 24mm lens it would give you different perspective than 85mm evn if you would crop 24mm image to have same angle of view as 85mm.
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