I am rather partial to the 60x90mm format. I have several old Agfa Isolettes which are 6x6 120 film camera, they do not have rangefinders or automation. The lens which is in a shutter with several speed, generally B, 1/25, 1/50, 1/100 and sometimes 1/200th of a second. When I tested the shutter speeds I found the following, 1/25=1/5, 1/50= 1/20, 1/100=1/60 and 1/200=1/60 of a second. The front element is rotated to focus( marked 1, 2, 5, 10 meters and inf.)
I removed the lens from the camera and made a lens board for it and stuck in on a 4x5 camera. To my surprise the lens covered easily the 6x9 format. The above camera is the result of that experiment.
The Agfa lens an 80mm f/4.5 lens focused at inf. has a focal length of 77.5mm. The film box was made just deep enough to handle the film. The lens barrel(6mm(1/4") plywood) was made to allow for the extra width of the image(90mm) and a little longer than required. Using a piece of ground glass at the film plane and focusing at inf. I adjusted the length to produce a sharp image under 10x magnifer.
The camera measures 166mm(6.5") long 95mm(3.7") high and 50mm(2") deep. To trip the shutter a piece of 1/16" wire was bent along the lens barrel, up the body and horizontal just over the top edge of the camera. There was enough room that a shutter lock could be placed just below the trip point.
The interior of the film box is similar that I've used on several other cameras. To create some tension on the film and take up spool, a piece of styro-foam was glued just below the spools and covered with the film backing paper( it has a slippery surface).
The pictures from this camera are reasonable given the age of the lens, I will continue with this experiment hopfully using a better lens.
I have been experimenting with different formats and wondered about a 60mm x 90mm monorail camera. This camera has been designed with a rotating back. I wanted to be able to make vertical images without rotating the camera body.
The camera will accecpt lens from about 65mm to 210mm, however there is a trade off with the tapered bellows and short lenses. The bellows will collaspe enough for the 65mm but there is little movement allowed( the bellows starts to bind) about 10-15mm(.4-.6")
The construction material of the body is pine( a very soft wood) with brass and aluminum metal parts. This is a prototype and the wood is easy to use. The front standard slides on the aluminum beam with a locking screw, the rear standard is geared with a rack and pinion movement, it will also lock for stability. Both front and rear standards have full swing and tilt, the rear stand does not rise/fall. There is a brass pendulum on the rear standard to make it plumb.
The ground glass viewing is done on a separate piece, placed in the same position as the film back. There are levels to maintain horizontal position in both planes.
With the film holder dark slide partially opened, the film guide and rollers can be seen. The pressure plate to keep the film flat is made from styro-foam with a piece of bristol board glued to the face and pained flat black. The hole near the center bottom is to view the frame number.
Since I have been experimenting with the different formats, changing the lens back and forth became a problem. I made a smaller(75mm) square lens board that will now screw to larger lens boards or directly to other cameras.
This is my first attempt at a hand held 60 x 175 format panoramic camera. Since I already had the back from the 60x175 mono-rail, it occured to me that all I needed was a small body to mount it on. The same held true for the ground glass viewing screen. The lens assembly is just a box that is calibrated to the focal length of Schnieder SA 90mm /f8.0 lens(8 meters). For an image that is closer than 8 meters, the lens is stopped down accordingly.
This variation is another step towards a more compact hand held panoramic camera (60x175mm 2.25x7"). The body thickness was kept to 45mm(1.75") so that it could be held comfortably, the balance of the focal length is made up in the bellows. It took 9 attempts at the bellows before I arrived at a good formula. There is a focus scale visible as a white square behind the left focus knob. It is scaled at 1, 2, 3, 5, inf.
The interior like other cameras that I've made is quite simple. There is spring tension on both the film and take up spools. The platen is made from a piece of tin and its pressure to keep the film flat is created by a thin sheet of dark grey foam. The film numbers are easily visible through the 12mm (1/2") hole under the brass plate. There are 2 spring clips to keep the back from accidently opening.
Thanks for visiting this page, if you have any questions please send E-MailReturn to Doug's home page.