Ernemann Heag O - Type A or Type B
I've own a HEAG XI (10x15), but that's a world of difference. I think you're going to have a lot of fun with that camera.
If it is a 'Normal' 9x12, another solution is a spring back addition sold in the 50's and 60's to convert this type camera to 3.25x4.25. Has a built in ground glass, spring back and allows you to use standard 3x4 graphics Type V film holders. You can still get 3.25x4.25 film from freestyle. Look on the Bay.
tim in san jose
Cutting 9x12cm film in fourths is just as easy as cutting 6.5x9cm film in half, since the smaller films are 0.5cm too wide and must be cut down anyway. The good thing is that such a small piece of sheet film is stiff enough that it doesn't need a film adapter - just put it in as if it were a glass plate. :)
That's a lens consisting of two elements symmetrically placed each side of a central stop. Since these are not achromatic, a small aperture is necessary to give satisfactory performance - the f:11 should have been clue enough for me: Wide angle lenses and Periskops were generally the only lenses to come with a max opening of f:11!
BTW, I'm moving this thread to "Plate Cameras", since that's what it is.