artBob Loc: Near Chicago

You have demonstrated that you do not know perspective. The edges are meant to show that, in the best alignment possible (near corner) the chests do not align, as the theory states they should. In perspective, btw, parallel lines (object) are supposed to converge, not remain parallel.

While I so anxiously await the pejoratives, I wish I could claim all the accomplishments you list. However, a practiced eye needs to be turned on them, so here we are:
"- You don't know the meaning of perspective."
Oops, wrong. I have taken several courses, and taught it in college myself. It is simple on its surface (apparently not to all), but cn get quite complex. As an example, we have been discussing two point perspective, when in the real world and in good drawing and photography, three point perspective exists.
"- You don't know how to resize to get the images to match."
Actually, I do. In Photoshop I have to use "Transform/Distort." Interesting that, as it implies to make photos align I have to distort one, in essence removing the distortion in it.
"- You don't have sense enough to not post an image that disproves your claim."
I would post anything that attempts to disprove my claim. I am not a fascist or anti free speech. Especially as a prof, contrary opinions have to be taken into account, contrary options backed with facts crucially so. There have been NO visual proofs submitted. Most "proofs" depended on people using their eyes to judge, rather than the only accurate way, superimposition.
"- You don't understand distortion."
A baseless claim I don't even know how to answer.
"- You don't understand geometry. That't not a character flaw but pretending that you understand it does not fool anyone."
Geometry does not enter into linear perspective. I did get a good grade in Geometry. I don't understand what you don't understand.
"- You claim that anyone who does not agree with you is wrong."
Wrong. I claim that anyone whose opinion is contradicted by visual proof and linear perspective is wrong.
"- You can't find a way to get out of the hole you have dug yourself into."
I shake my head at this. Are you perhaps projecting?
"- You are willing to lie."
And you, sir, are a scoundrel. As an educator, I am most unwilling to lie. It is like a sacred trust. Projection?
"- You insult people who disagree with you."
If provided an example of my insulting someone who did not first insult me, I will apologize.
"- Everyone else has been right all along and you have been wrong."
"Everyone"? Impossible, as there have been differing opinions. Typical, however of your baseless claims, announced with pretend authority, unsubstantiated by proof.

Thank you for the summation of the gripes of those who have not provided any proof of the doctrine they read somewhere, giving me a chance to summarize the counter-arguments.

(Download)

Jack 13088 Loc: Central NY

The only way to fool yourself into thinking that changing lens without changing moving the camera changes the perspective is to perform the experiment with the subject quite close to the lens. Not moving the “camera”really means not moving the front nodal point which does move with respect to the tripod screw when the lens is focused on objects.

That last sentence would be easier understood if written by someone with better writing skills than I.

artBob Loc: Near Chicago

"this time I used lens profile correction" Yikes! By "correcting," that just proves that lens DISTORT.

artBob Loc: Near Chicago

While this may or may not be true (why don't you do what you suggest and share), it is true that in the real world different focal length lenses distort perspective.

Skiextreme2 Loc: Northwest MA

No one has posted any links that give answers, so here are a couple. If you search for "does focal length change perspective", it seem that, according to a LOT of "professionals" disagree with you and explain why it does not.

https://photonaturalist.com/understanding-perspective-and-focal-length/

https://www.diyphotography.net/definitive-guide-focal-length-perspective-zooming-feet-nonsense/

https://photographycourse.net/focal-length-perspective/

Skiextreme2 Loc: Northwest MA

Distortion is not perception. Lens elements cause distortion.

selmslie Loc: Fernandina Beach, FL, USA

And, of course, he got it wrong and was called out on it, "The pedant in me was a little caught by the title of this essay, which may suggest to the novice that lenses (i.e. focal lengths) can alter perspective directly. Of course, the only way to change perspective is to change the camera position. Which lens you choose can help to decide this, but does not actually affect the perspective." In other words, the author misused the term.

The response, "Thanks Geoff. I’m not going to argue the definition of perspective with you." Oops!

The author, like the OP, is confusing perspective with field of view.

selmslie Loc: Fernandina Beach, FL, USA

Parallel lines that are perpendicular to the line of sight (the lens axis) will never converge unless there is something wrong with the lens.

Without distortion they will remain parallel. With barrel distortion they will eventually come together on both sides of the image (outside the field of view). With pincushion distortion they will continue to get farther apart and never meet.

You really don't understand this stuff, do you.

Keep digging. You continue to demonstrate that you don't know what you are talking about.

selmslie Loc: Fernandina Beach, FL, USA

My previous post just proved that you don't understand it.

Linear perspective is all about geometry. It the essence of the conversion of a 3D scene into a 2D image. You don't understand that you don't understand geometry.

mgoldfield

Bravo ArtBob!

olemikey Loc: 6 mile creek, Spacecoast Florida

My perspective on this thread was to steer clear!!!!

dsmeltz Loc: Philadelphia

You mean sort of like the sign at the zoo? "Please do not feed the animals"

selmslie Loc: Fernandina Beach, FL, USA

For anyone who does not want to follow the links, here are the imprtant comments :

https://photonaturalist.com/understanding-perspective-and-focal-length/
"The series of images you have on the post you linked to actually helps prove what I’m saying here: that perspective is determined only by camera-to-subject distance, NOT focal length."

https://www.diyphotography.net/definitive-guide-focal-length-perspective-zooming-feet-nonsense/ Some very clear demonstrations along with,
"There are all kinds of erroneous “facts” about it. Like focal length being that which distorts your subject, and not the distance to the subject. ... You can see from this animation that with a theoretically perfect lens, focal length changes absolutely nothing about the perspective of the subject. It’s simply cropping into a tighter field of view or opening up to a wider one. ... Changing focal length does nothing to perspective whatsoever. It’s the moving that changes the perspective. Changing the focal length simply changes the crop of the scene before us."

https://photographycourse.net/focal-length-perspective/
"While focal length does not change perspective per se, it does change how the subject is represented."

jeep_daddy Loc: Prescott AZ

Wow, 8 pages and growing. Quite the argument.

At the Canon seminare I just attended, the same question was posed to the Canon expert about perspective and using different lenses at the same focal length such as using a 50mm prime and a 24-70mm zoom at 50mm. He said, "for the most part the perspective will be the same." He went on to say that there will be some slight differences, but that for the most part you wouldn't be able to tell them apart. I'm glad he didn't beat the horse until it died and then keep beating it like they've done here.

I'm sure that what he meant by for the most part you couldn't tell them apart and that there are slight differences, is that some lenses have slightly different diffraction, distortion, and coatings along with the aperture blade count being different which can all affect an image slightly when compared across the board.

So if you were to take a 50mm f/1.8 prime, a 24-70 f/2.8 @ 50mm , a 24-70 f/4 @ 50mm and a 18-200 variable aperture @ 50mm and took a picture on a tripod, then stripped the metadata from each image and mixed them up, you wouldn't be able to tell which one was which if you used the same exact settings such as f/stop, shutter speed and ISO settings.

CO

What you're seeing there with the photos of the ice chest that I posted are small differences in the magnification. I zoomed the lens between a full frame camera and a crop sensor camera. It's not perfect. Look at the sets of photos that I posted on page 3 that were taken looking along the walkway at the marina. You can see the orange cone close to the camera and the club house in the distance are the same size at both focal lengths.