The relative angular sizes of objects didn't change and perspective didn't change, so you didn't actually change the compression. You magnified everything at the same rate, distances and sizes. Had you moved your PoV, you'd have changed the relative apparent sizes of the objects.
May 7, 2023
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A photographer can get closer and use wide angle to crop out distractions or obstructions in foreground, or they can stand further away and use telephoto to crop out distractions in the background. Moving backwards reduces the size of the background relative to the size of the subject, while moving forwards increases the size of the background relative to the subject. Cropping the background makes the background objects larger, while expanding the background makes the background objects smaller. Increasing the size of the background objects makes the foreground objects appear smaller, while reducing the size of the background objects makes the foreground objects appear larger. It is the most important technique of composing landscape and architecture photographs, much more than an "optical illusion", it can completely change the photograph. Compression is not about uniformly increasing magnification of the whole photo but about selectively increasing the magnification of the background.
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It depends on how you define "lens compression".
Clearly your definition is different to mine.
What you are describing is how to use lens compression to get different looking photos.
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The point is, the main factor is the distance of your point of view to the objects in the scene, it's not the lens that causes the compression. 'Lens compression' is a bad name.
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If the 15mm lens is f/1.4, then it's maximum entrance pupil is 15mm/1.4 = ~10.6mm. For the slowest 800mm lenses, say the Canon RF800/11, the maximum entrance pupil is 800/11 = ~71mm. From the same distance from a subject, relative DOF depends on the pupil size. So, even the slowest 800mm lenses have much, much shallower DOF than any 15mm lens cropped to an 800mm-FF-equivalent FOV.
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We'll just have to disagree on this one :-)
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That's only true if you don't crop and show the full image at the same size. As a person who takes a subject-oriented approach to photography, that seems like an artificial thing to do. What is your subject, the room, or the darts?
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I know what you mean, but these views don't look anything like actually being closer. They can just "feel" closer.
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The psychological compression effect has nothing to do with lens focal length, or with the lens, except inasmuch as DOF affects the visibility of the effect, but that is a function of pupil size and distance; not focal length. Using a narrow AOV at a wider angle of display is not a focal length phenomenon.
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Thank you for your thoughts. We clearly have a different definition of "lens compression" so we'll have to disagree on this one :-)
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Perhaps this thread could use more references and less unsupported statements.
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I don't have a definition of "lens compression", because there is no such thing as "lens compression".
All the phenomena spoken of here that are real, are due to relative magnifications of various objects in a scene due to relative distances, and that somewhat variable psychological effect of having significant angular magnification. A crop is as good as a long focal length, or even pressing your face up against a mural made from a wide angle lens.
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This is where we disagree. In the example I posted earlier, I mentioned that although nothing actually moved Object B will appear to be closer to Object A after you zoom in.
Many people call that "lens compression". If you don't want to call it that or prefer to call it something else that is fine as it is your choice to make.
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Some good animations and diagrams here:
mastinlabs.com/blogs/photoism/the-truth-about-lens-compression
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So you think that this shot is an example of telephoto compression?
That is exactly the sort of nonsense I was referring to in the title of this thread.
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That article is another example of the nonsense I mentioned in the title to this thread.
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So there's a lot of nonsense here except Tom. Is that right Tom?
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To those who argue that telephoto compression is all down to distances:
Suppose the scene in front of you is a long straight road with one vehicle 100 yards away, another vehicle 300 yards away, another 400 yards away and a fourth a mile away. If you take a shot from your present position, will it show telephoto compression?
