JACOBCO

Recently, I became interested in learning photography and bought an inexpensive used DSLR camera and lens set (Canon EOS Rebel XT). If you know me, you would not be surprised to learn that I soon became interested in how lens stacks work, and lenses designed for other purposes might be adapted to work with my camera. I came across a reference to someone using old film projector lenses with their cameras, usually with old photography bellows or a series of adapters meant for things like telescopes. I instantly became fascinated with this idea and started poking around in my collection of random junk for lens build candidates. As a first attempt, I settled on this Apollo 16mm film projector from the late 1940s (I think) because it has an easily removable lens. and was sitting on a nearby shelf.

I originally bought this projector in an online auction because it came with a vacuum tube audio amplifier, though I still have not had time to use it.

I later decided to convert this projector into a display piece with a nice wooden base and LED lamp. It does not function as a projector, but still looks cool.

The lens is stamped with a 2" (50mm) effective focal length, making it a useful candidate for this process.

It is also stamped "astigmatic" and "coated", though I expected that the manufacturing tolerances of the era would lead to some interesting results.

After some test images snapped physically holding the lens in front of the camera, I designed and 3D printed a mount to hold it more permenantly. I put a hole in a Canon EF body cap design that I found online and designed another bushing to hold the lens tightly. These two parts were printed using ABS plastic and glued together with CA adhesive. This design does not allow easy adjustment of the distance between the lens and camera sensor, resulting in a fixed focus.

I initially hoped that the lens would be able to focus on objects at a reasonable distance from the camera. Unfortunately, the lens stack was designed to focus onto surface only millimeters away, which is not possible with this type of camera. This means that this projector lens will only focus on things very close to the front of the lens. Though I was initially disappointed with this realization, I became exited again once I saw the quality of the images produced. I have posted a few of them below.

Some of the initial images taken in low-light (the first two) seem to have a dreamy nostalgic vibe. I later took a walk around a local park and photographed a few interesting plants. The lens has a very shallow depth of focus, drawing the eye to the in-focus subject of the image and away from the beautifully blurred background. This blur can be seen especially well in the 5th image, where the background almost appears to swirl around the bundle of leaves in the center.

Though this lens is not practical for everyday use, I am sure that I will use it whenever I am looking for this type of interesting close-up effect and am not in a big hurry for the result. I plan to continue adapting different types of lenses to my camera, and will post an update when I am able.

Email: jacobcodotnet@gmail.com