What a great batch of info!
It looks to me like the drawing aid described in the “Homemade Camera Lucidia”, which the author points out is actually not a camera lucidia and names the “Mirror Lucidia”, would be pretty easy to build and to use, and most significantly that it would let you move your head around some without spoiling the effect - at least, if I understand it right. Though I think moving closer and further (in their sketch that would be moving your eye vertically) would make the relative scale change between your drawing and the image you see. It also looks to me like the mirror lucidia would blur things a little because the paper and the image would be at different distances. Some other device cited above uses a slightly curved surface, a mirror I think, to fix this.
CalMeacham, I am impressed no end. I actually read Optics and Photonics News occasionally, though I didn’t catch one this past summer. I’ll see if I can find it.
It is pleasant to see Edmund cropping up again. I had the pleasure of giving Bob Edmund a tour of a telescope I was doing variable star work with, about 30 years ago. This telescope, a camera with a guide scope, had a triplet lens of 8" clear aperture for the camera, made by Cook, and the guide scope had a 5" acromat made by none other than Alvin Clarke. They have grown from Edmund Salvage to Edmund Scientific to whatever deal it is they have now, having broken into several Edmunds plus this Anchor Optics. The Mad Scientist room at their Barrington location was always a pleasure. I haven’t ordered from them since, well, when was it? Yesterday afternoon, it turns out.
Picunurse, I think I remembered things wrong when I wrote my OP, so it did sound more like I want an opaque projector than anything else. But I’m pretty sure now it’s the camera lucidia or some variant on it that I was remembering.
All the stuff about funny perspective is interesting. There would be a subtle shift if the artist sat in the same position and worked with a camera lucidia that was below his line of sight to create parts of the drawing, and used his forward line of sight for other parts, like filling in a face. Other than that, though, I’m pretty sure the camera lucidia would not introduce any special distortion, and that you could take a picture with a film camera or digicam from the eye position and see what the camera lucidia was doing. Of course, you could introduce shift and tilt distortions with a camera lucidia the same way you would with a view camera.
