Building a Giant Room Camera (for 10€)

Ana and I, shot with our Giant Camera

It all started as a College group project. There were two people in the group — me and Ana — and we needed to create images using alternative photographic processes, so we immediately thought “What could be more alternative than building your own camera?”.

I had already built some giant pinhole cameras before so I knew the basics. We just needed to do the same thing and add a lens. But not just any lens — we wanted to build our own.

The math:

The balcony outside (where we intended to have our models) was about 1 meter long so we didn’t have a lot to work with. We’d need a lens that was long enough so it would focus the image as far as possible from the window, but short enough to fit a head and shoulders portrait of someone standing outside. We guesstimated something along the lines of 600mm to 1000mm would work.

Of course we could have just used a real lens at this point, but that presented two problems for us:

  1. It felt like cheating. We were building the entire camera by ourselves and wanted it to feel ours. So if we could build everything including the lens, that would be great;
  2. Even if we wanted to use a commercial lens, we would need to find one with the appropriate focal length and an image circle large enough to shoot large paper negatives.

After some thought, we figured the easiest (and cheapest) way of building our lens was to use a magnifying glass.
Magnifying glasses are converging lenses, which means they focus the light rays onto a focal point at a certain distance. Like this:

That meant we could use a single element to build our lens — and any images produced with it would look sharp in the center and very soft at the edges. That wasn’t exactly a problem for us; we just needed to get the eyes of our model in the center of the lens and the rest would gradually fall out of focus.

We found a magnifying glass with a focal length of around 700mm and went with it (to figure out the focal length of a converging lens, we held it horizontally inside the store until we could see the lights from the ceiling focused on the floor. Ideally the lights would be farther away but we figured it was close enough).

Here’s a list of what we used (we only spent 10€ on supplies):

  • Duct tape
  • Black cardboard
  • Box (an old pinhole camera, actually)
  • Easel (used to place the paper)
  • 9cm lens from a magnifying glass
  • Red filter
  • Tripod
  • Room with a window and a balcony

And the building process:

  1. We isolated the room from outside light using black cardboard and duct tape to cover the window;
  2. Then we estimated the average height of a person sitting outside, on the balcony and did a tiny hole in the cardboard in front of where the face would be;
  3. At this point we had a pinhole camera and we could see that it worked so it was good news;
  4. Then we built the lens, using the box as some sort of bellows (that would allow us to focus) and a magnifying glass with a focal length of approximately 700mm;
  5. We put the easel at the appropriate distance and added a piece of cardboard to hold the paper later. The height of the easel could be adjusted according to the mode’s height;
  6. Finally we put a tripod holding the box, making the whole system more stable and allowing for tilt movements on the lens;
  7. Our shutter was built using a red filter. Having it in place would allow us to see what we were doing while putting the paper on our easel without exposing it. Then we’d just remove the filter and put it back in place, exposing the paper in the meantime.

Our focal length was about 700mm and our aperture was about f/10 (our lens had a diameter of 90mm, but after applying all the duct tape we needed to put it in place we were left with 70mm of “usable” lens).

Random picture of me holding a wet plate done with the camera. It didn’t come out very well.

Shooting 18x24cm paper negatives with the camera:

  1. This was all done at night so we could open the shutter, fire a strobe using a radio trigger and close the shutter safely. If we did this during the day, the ambient light would expose the paper and we wouldn’t have absolute control over our lighting;
  2. We used an 800Ws strobe with a square 80cm softbox as our only light source;
  3. Shooting the portrait consisted on the following steps:
  4. Sitting the model on the balcony;
  5. Focusing;
  6. Putting the 18x24mm paper on the holder;
  7. Opening the shutter;
  8. Firing the strobe using a radio trigger;
  9. Closing the shutter.
  10. After the exposure, the paper was developed inside the camera itself (the camera also worked as a developing lab).

After developing the negatives, we did some contact prints and then selenium-toned them. Our initial plan involved shooting wet plate collodion also but we didn’t like our results.

In the future, we plan to do the wet plates again as well as some really big glass negatives using gelatin.

Here are some of the results:

And the behind-the-scenes video:

You can see the entire project HERE.