Rethinking focal length conventions

Started 7 months ago | Discussions thread
Pixel Pooper Veteran Member • Posts: 3,955
Re: 6%
1

Phil A Martin wrote:

Pixel Pooper wrote:

Phil A Martin wrote:

Pixel Pooper wrote:

It depends on how the image is viewed. A focal length equal to the format diagonal gives a natural perspective when the viewing distance is equal to the image diagonal. Images viewed from closer have a shorter normal focal length, and images viewed from farther have a longer normal focal length.

People say this quite often here but where is your proof?

It's easy enough to prove it to yourself. Just look at any image from a distance from a distance proportional to the focal length and the perspective will appear normal.

No it doesn't and "from a distance proportional to the focal length!", who looks at photographs from 50mm, let alone 28 or 17mm ? Maybe you haven't explained it correctly?

For natural perspective the relationship between viewing distance and image size should be the same as the relationship between focal length and sensor size. If the focal length is equal to the sensor diagonal, the viewing distance is equal to the image diagonal and if the focal length is half the sensor diagonal, the viewing distance is half the image diagonal. This, as you said earlier, is part of the ABC of photography and is explained here in The Manual of Photography:

Post (hide subjects) Posted by
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
tko
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow