My theory is that most perceived perspective errors arise when a photograph captured with a wide field of view is shown in a narrower one; a perspective-"distorted" image looks more realistic if you put your nose up to the screen so the photograph fills more of your field of view (enlarging the center and eventually squashing the edges). And tricks like Panini projection and Piranesi's arches are ways of making features at the edge of the screen "take up" the correct amount of viewing angle (without bending straight lines) when the painting takes up less of your vision than the original scene.
Piranesi's Perspective Trick (2019)
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Re: Piranesi's Perspective Trick (2019)
#72A great example of something you can feel but I never had the words for.
> But here is the same elevation drawn using correct rectilinear perspective. I hope you will agree that the Piranesi version is much more legible, the furthest house above is easier to see and the nearest house isn’t horribly distorted as it is below.
The section with this bit has some pictures that really illustrate the effect.I wish there was an easy photoshop way to recreate this
Re: Piranesi's Perspective Trick (2019)
#73I half remember an articled or docu from a while ago where someone was analyzing the perspective in some studio Ghibli backgrounds, finding that many are artistically "distorted". When this was brought up to one of the artists, they responded along the lines of: "The western idea of 1, 2 and 3 point perspective is just one way of drawing perspective and not necessarily more 'correct'." (I guess that's true, even if you think of 1 and 2 point perspective as cropped versions of a 'true' perspective image, the lines wouldn't be completely straight in reality. It's all different kinds of artistic license).
Re: Piranesi's Perspective Trick (2019)
#74I think that this trick or something like it is used in ski mountain maps. For example: https://files.skimap.org/js03b74i9eokcg2y1iakwdtv2av6.pdf
I don't know how to confirm this; the distortion just feels similar to me.
Re: Piranesi's Perspective Trick (2019)
#75> By legibility I mean that the Piranesi distortion is easier to read, and that to anyone unfamiliar with photographs, that hasn’t grown up with TV, photographs and magazines, the Piranesi version would look much better, and the true perspective would look rather odd. I think this is a key point that people are often unaware of. For instance, whenever I see a modern artist who has painted photorealistic art, I read d…
You make good points, but if we really perceived reality differently than cameras, someone would write an article about that - after all you can take a photo on your smartphone and compare to your IRL view. Yes it's hard to make it match but it's possible. Since no one made an experiment to show this, and since we understand pretty well the optics of a human eye, I think the cameras actually reproduce human vision de…
One thing that cameras can do that we can't do with our (unaided) eyes is change focal length. When a camera zooms in or zooms out, there is a change in the geometry of perspective. When zooming in, the change is difficult to see but is well documented. Portrait photographers are well aware of this because it tends to make people look better. When zooming out, especially when zooming out to a very wide field of view, the effect can be very noticeable. When people use a phone camera to take a picture of a group of people, the people at the edges of the photo can look very flattened and unnatural. Again, this effect is well known and very much discussed and written about in photography and art. In the article about Piranesi's work, we see a very interesting remedy to the perceived distortion of a wide view. Again, these works show a field of view, and therefore a focal length, that is not possible with our eyes. We can visualise in our mind's eye what the scene looks like but what our eyes are doing is moving around the scene while our visual cortex and ultimately our mind's eye construct a mental model. In our minds, we know that the arches of the bridge are the same size and shape despite being distorted by distance. We can look at what's in front of us and see that in the receding row of arches the nearest appears to be bigger than the farthest but we also know that's just an artefact of our point of view. Things are subtly different when we look with our eyes at a photograph, painting or drawing. It's not the same as when we see something in real life, we're looking at a 2 dimensional representation of a 3 dimensional scene. We do see the perspective in the picture - we don't see a bunch of lines on a two dimensional plane. Our brains are making that happen and are making some adjustments along the way. It just so happens that something we have difficulty adjusting so it "looks right" is a very wide angle scene. That's because we don't ever see a very wide angle scene in one glance in real life.
Re: Piranesi's Perspective Trick (2019)
#76I'll take this opportunity to drop the fact that I'm kind of obsessed with the book "Piranesi", where the main character (named after the artist in the article) survives in a world which is just endless corridors of classical architecture, statues, and staircases. It's an incredibly calming experience, I've listened to the audiobook over 10 times before sleep. Highly recommended.
Absolute banger. I am convinced it will be held up as a true classic.
Re: Piranesi's Perspective Trick (2019)
#77I'll take this opportunity to drop the fact that I'm kind of obsessed with the book "Piranesi", where the main character (named after the artist in the article) survives in a world which is just endless corridors of classical architecture, statues, and staircases. It's an incredibly calming experience, I've listened to the audiobook over 10 times before sleep. Highly recommended.
Came here to say this. I loved the voice of the main character.
Re: Piranesi's Perspective Trick (2019)
#78Lol, it's literally affine texture mapping.
Read the article and look at the examples - there still is perspective, just no perspective distortion (or the other way around, there is a perspective distortion to keep some lines parallel, where in normal view this wouldn't be the case).
Re: Piranesi's Perspective Trick (2019)
#79The panotools wiki has a good comparison of different projections of the same photo. Google Streetview uses equirectangular pictures to store 360° images. Panini is another type of equirectangular. Examples Panini: https://wiki.panotools.org/File:Ben_Equirectangular_panini.j... Equirectangular: https://wiki.panotools.org/File:Big_ben_equirectangular.jpg Full list: https://wiki.panotools.org/Projections
if you have any connection to the admins of that wiki, it would be great to get MultimediaViewer extension enabled - https://www.mediawiki.org/wiki/Extension:MultimediaViewer they're on 1.35 right now which is a bit out of date (lifecycle - https://www.mediawiki.org/wiki/Version_lifecycle ) but an older branch of MMV should work fine on 1.35
I hate this behavior on Wikipedia. Worst part is that people then share links to those views which don't work without running javashit.
Re: Piranesi's Perspective Trick (2019)
#80Surely this introduces some curvature to the diagonals? I can't see how the perpendicular lines can be in correct perspective with the diagonals being parallel unless something is curving. I guess because it's preserving the perpendicular lines and the curvature is subtle, it's not very noticeable in typical architectural pictures.
It's not a real projection as in a panosphere -> rectangle mapping but rather a local transformation of specific objects.