Years ago I was at an exibition in het Booymans van Beuningen Museum in Rotterdam about the dutch church painter Seanredam (1600).
I was amazed to find out that he could have been the first LF architectural photographer even before photography was invented.
His work shows so much depth.......
Concerning the "natural" viewing perspective, perhaps the simplest way to naturally force the viewer to place him/herself at the correct distance is to contact print (???).... these massive enlargements (which seem to be all the rage now) just push people back, it seems to me. Contacts tend to cause people to view them at arms' length.
How about this: when you go to a movie, where do you prefer to sit? Some folks like to sit right up front so that they are turning their heads to take in the scene. I did that once and actually felt a bit ...dizzy... after a while, but indeed one does feel "part of" the scene. Especially if the screen is curved (IMAX).
I suppose this theory of natural viewing perspective perhaps doesn't take into account the neck muscles. A reasonable question might be whether one wants to take in the whole scene at once, or rather look around through it, exploratively, from left to right. There is nothing "unnatural" about that last option- we do look around when we view actual scenes in the real world, no? That becomes a bigger issue with pano aspect ratios, of course. I find that squares satisfy me the most, personally, because of the equal weighting of the whole, which causes me to think of it as a Whole rather than a collection of sub-subjects. Panos, which I admit that I am just now starting with, force an entirely different way of seeing.
The thing that I see interesting here is the need to work backwards from the place the print will be and the intended viewing distance to the choice of lens and camera.
To get the rough theoretical "best" perspective (that 3-D walk into the photo or vertigo inducing look) for a given viewing distance of say 1 meter where the planned print size is 1 meter creates a 1:1 ratio of format:focal length (35mm film:35mm lens, 645 format:56mm lens, 6x7 format:70mm lens, etcetera...)
The "perfect" format to focal length ratio becomes basically a fixed value once the size and distance are known. This would be true of wall prints or billboards or wedding albums.
This is the perfect argument for using fixed length lenses that match the intended viewing distance to print size ratio. Zooming/cropping with your feet becomes imperative to maintaining the perfect ratio.
For me this also answers why the 85mm and 105mm lenses are so popular for portraits with 35mm cameras, it's the 8x10 prints that define the mass market. The short (un-cropped) edge 8" and the viewing distance of maybe 20" (roughly the distance hand held) = a 1:2.5 ratio. For 35mm multiply 35 by 2.5 and you get 87.5, for a hallway or desk setting, slightly longer than normal hand held distances you might get out to say a 105mm lens.
Following this logic out one more step, if I want to sell bigger prints than 8x10's, say 20" prints on the long edge, a shorter focal length would be better for a "normal" viewing distance.
For 35mm film, 35mm to 50mm lenses would theoretically create a "perfect" perspective for 16"x20" hallway prints or modern wedding album spreads (10"x20"). This same ratio pushes living room prints, with say a 5 foot planned viewing distance to have a long edge of about 42 to 60 inches.
I like that; shoot normal to wide, get closer with the camera, sell bigger and better prints!