CAMERA LUCIDA

I got a bee in my bonnet about Cameras Lucidae and Obscurae this morning.  They are simple devices used to transfer images to a drawing surface. The ad above is the most widely known variety of Camera Lucida, a cheap and flimsy model which I saw once in a thrift store and decided it was too crappy to waste half a buck on.  It is a pretty fanciful depiction, as the posture of the artist is considerably different from the peering through a hole that you must do to use it properly.  Also, it inverts the image so she would be drawing him upside down.  Using a diagram from this Free Obscura page, I built the device below out of scrap cardboard and glass in about an hour.  I had to cut a 3 x 4 inch piece of window glass, and stuck everything together with that little glue gun from the dollar store.

I thought a rectangular slit might be better than a hole so both eyes could be used.  This is what you see when you look down through the slit - an image of the window of my studio is superimposed over a piece of paper on the workbench.  

It would require an armature like the device in the ad to use properly, but I am wondering if it might instead be attached to the brim of a hat.  You would have to hold your head quite still for that to work though.  Well it is almost time for lunch.

ADDENDUM: Here is the Camera Lucida hat.  In proper use I would be looking straight down at a piece of paper. Not really functional, and the Camera Lucida itself is of marginal use at best.  I can't imagine going to the trouble of really using it.