While I'm not going to purport to copy the likes of Shi Guorui (http://www.slowlight.net/blog/?p=79)

I am interested in the feasibility of such a concept.

Could it really be as relatively simple as constructing a light-tight box with lumber, blacking-out materials, etc.? And how could I calculate the distance from opening to viewing surface?

I may construct this as a simple viewing room where participants can trace the image they see, or have large sheets of photo paper tiled to make a large photographic image.

Any help is gratefully accepted.

This might help. It suggests 1:100 ratio of lens opening (pin hole) to screen distance.

http://www.cameraobscuras.com/faq.html

Early artists used the camera obscura when painting. Recently the concept has been taken to the extreme with the aircraft hangar pinhole (http://www.legacyphotoproject.com/) by the Legacy Project.

And google Abe Morrell... he routinely turns hotel rooms into pinhole cameras, and photographs the projected images on the wall with all the furnishings in the room. They are really striking!

The to my understanding largest walk-in camera obscura (with a lens however) is to be found in the history-of-film museum in Mülheim in Germany:

http://www.camera-obscura-muelheim.de/cms/installation_1992.html
http://www.camera-obscura-muelheim.de/cms/geschichte__technik2.html

and for the rest of the world:

http://www.camera-obscura-muelheim.de/cms/camera_obscura_weltweit1.html

I'm thinking of something along the lines of what Shi Guorui has done, only it would be nice to use positive paper mentioned on another forum at this site.

Any hints on where to find info on constructing such a beast? The main concern, apart from light-proofing, would be the size of the aperture and its distance from the back wall/paper surface.

i agree with looking at the work of abe morell ...
some of his books tell how to turn rooms into pinhole cameras. maybe it can help you with some of your questions.
as for light proofing, you can find light flocking material ( black rubbery cloth probably bought at a pro-camera store ... i know i got
some at cameras.com / ep levines a few years ago .. ), or since you are building a "room" you can paint the walls flat-black.
the usual number used for pinhole / coverage is 3" x focal length. you can easily make a pinhole yourself with a sheet of metal
and a needle and sand paper.

-- good luck!

john

A somewhat traumatic memory just surfaced... Years before I knew of the existence of the camera obscura.

Probably 35 or more years ago... (on CFB Petawawa) an adolescent prank in which I was thrust inside a dark shed by a bunch of bullies... which they then peppered with fist-sized boulders. As the wooden door began to splinter, shards of light painted the inside of the shed with superimposed images of the outside hoard. Despite the horror of the moment, it was really visually beautiful. (which I would never let on to the brutes) Now... where is my therapist's pager number? :D

[edit] Oh, yeah... did I mention they threw a girl in the shed with me... (hee hee) For the life of me I can't remember how the whole thing came about. (or the girl's name... sigh)

A long time ago a guy made his van into pinhole camera. I think someone else used a U-haul truck as a pinhole camera.

Jon

And in 2006, they made one out of an aircraft hangar (http://www.pinhole.com/archive/421).

Not very portable. :D

DaveT