The Ilford Film Box Pinhole Camera

Published on 28 April 2020

Since 2001, the last Sunday of April marks International Pinhole Day. I had no idea of this until this past Sunday which happened to be the last Sunday of April. Never having tried pinhole photography I though “what the heck” and went ahead and built a pinhole camera.

For a few months I have had an empty box of Ilford XP2 Super sitting on my desk begging me to find a use for it. Since a camera is just a light-tight box holding the film, it struck me that it would be pretty cool to turn this box into a camera. Being the photographer that I am I rigged my Nikon FM3A fitted with the superb Nikon Micro-NIKKOR 55mm f/2.8 AI-s on a tripod next to my desk and shot a few frames during the process, The film was, you guessed it, Ilford XP2 Super which I souped in Kodak’s HC-110 dilution B for 5,5 minutes at 21C.

You’ll need the following:

  • An empty box, ideally one like that in the photos below

  • A Hasselblad or another film magazine of similar size

  • Black duct tape or black water colour

  • Scissors and knife

  • Something with which to make a very small hole

  • Ruler

  • Aluminium foil

  • Tin can

How to do it (click on the images for larger versions)

Ilford Box-source
Trace the outline of the magazine’s edges on the back of the box using a knife. On the magazine, measure the distance from its edges to the edges of the film gate. Using the measurements, mark the edges of the film gate on the back of the bo

  1. Trace the outline of the magazine’s edges on the back of the box using a knife.

  2. On the magazine, measure the distance from its edges to the edges of the film gate.

  3. Using the measurements, mark the edges of the film gate on the back of the box using a knife and a ruler.

Cut out the film gate in the back of the box. To reduce reflections, make the insides of the box black. Don’t forget the inside of the front lid of the box. I used black duct tape, but it is probably better to paint using matte black colour

  1. Cut out the film gate in the back of the box.

  2. To reduce reflections, make the insides of the box black. Don’t forget the inside of the front lid of the box.

  3. I used black duct tape, but it is probably better to paint using matte black colour since duct tape is quite shiny.

To find out where the hole should be made, place the back of the box over the front of the box. Trace an X using the knife. The film gate will not be perfectly centred in the box so make sure you place the front of the box correctly.

  1. To find out where the hole should be made, place the back of the box over the front of the box.

  2. Trace an X using the knife.

  3. The film gate will not be perfectly centred in the box so make sure you place the front of the box correctly.

Cut a suitable hole in the front using the knife. It need not be very large, perhaps 1x1cm.

Cut a suitable hole in the front using the knife. It need not be very large, perhaps 1x1cm.

Cut out a square in a piece of duct tape. Using a sharp object, pierce a very small hole in a piece of aluminium foil.

  1. Cut out a square in a piece of duct tape.

  2. Using a sharp object, pierce a very small hole in a piece of aluminium foil.

Here is a close-up of the hole. See the below for more information on the size of the hole, f/stop etc.

Here is a close-up of the hole. See the below for more information on the size of the hole, f/stop etc.

Cut out a U-shape from the piece that was removed to create the film gate.

Cut out a U-shape from the piece that was removed to create the film gate.

Cut a piece of metal from a small cigar box made of thin metal. It is possible to do by tracing and then cutting with a knife. Make sure that the metal is at least as wide as the outer edges of the U-shape made earlier. Bend the metal on one

  1. Cut a piece of metal from a small cigar box made of thin metal. It is possible to do by tracing and then cutting with a knife.

  2. Make sure that the metal is at least as wide as the outer edges of the U-shape made earlier.

  3. Bend the metal on one side to create a handle.

Attach the U-shape to the front of the box using duct tape. Cut the shutter to an appropriate size using scissors. The shutter should slide fairly easily in and out, which it will not do if it is wide enough to touch the duct tape..

  1. Attach the U-shape to the front of the box using duct tape.

  2. Cut the shutter to an appropriate size using scissors.

  3. The shutter should slide fairly easily in and out, which it will not do if it is wide enough to touch the duct tape..

Attach the film magazine with duct tape. To ensure that it is light tight hold up against a lamp and look from the inside of the box. Be particularly careful along the dark slide slit. Too much duct tape will interfere with the dark slide.

  1. Attach the film magazine with duct tape.

  2. To ensure that it is light tight hold up against a lamp and look from the inside of the box.

  3. Be particularly careful along the dark slide slit. Too much duct tape will interfere with the dark slide.

 
The final creation, ready for pinhole fun!

The final creation, ready for pinhole fun!

 

A few thoughts

The Pinhole

A search in the Wikipedia reveals that there is a formula for calculating the optimal diameter of the hole:

In this formula d is the pinhole diameter, f is the focal length (i,e, the pinhole to image plane distance) and λ is the wavelength of light. The Wikipedia also says that “for standard black-and-white film, a wavelength of light corresponding to yellow-green (550nm) should yield optimum results. For a pinhole-to-film distance of 1 inch (25 mm), this works out to a pinhole 0.236 mm in diameter. For 5 cm, the appropriate diameter is 0.332 mm.”

That all sounds great, but how does one go about creating a pinhole that is precisely 0,2 or 0,3mm, let alone measure that the hole created is that exact size? Not easily done. If one has a digital camera handy one can make a few different holes and see which gives the sharpest image. Or if one prefers to embrace the whimsical side of pinhole photography, one can opt for the wild-stab-in-the-dark method of camera manufacturing and just chance it.

F/stop and exposure

There is a really fascinating site called mrpinhole.com with a lot of information, including an exposure calculator. In order to use it one needs to know the pinhole’s f/stop. The f/stop is calculated by dividing the pinhole to imaging plane distance by the diameter of the pinhole (both in millimetres). As an example, a 50mm distance divided by a 0,3mm pinhole results in f/166.

Mr Pinhole has a handy exposure calculator to calculate an exposure chart. Just take a reading using another camera or a light meter app on the phone set to the ISO of the film in the pinhole camera and to f/2.8, f/8, f/16 or f/64, and then find the correct line in the chart. Since exposures quickly become quite long reciprocity failure may come into play. It is a good idea, therefore, to check the information sheet of the film you are using to obtain the correct exposure time.

The film magazine

I used a Hasselblad A-12 film magazine which will not allow winding the film using the crank. There is a gear which prevents this. I believe it should be possible to create a hook to operate the gear and override, but I didn’t try that. Instead I removed the magazine after each image, attached it to my Hasselblad (which I had previously fired) and wound the film. It is very easy to remove and re-attach the duct tape.

It would have been more convenient to use one of the old Hasselblad 12 magazines (the kind with the peek hole in the back). It should be possible to advance the film using the crank on those. The only hitch is to figure out how many turns to turn the crank to wind one frame.

Results

This camera is an epitome of imprecision, which is part of the fun (the other part, naturally, being to have built it myself). The risk of light leaks shouldn’t be underestimated, the shutter is completely unreliable, being operated entirely manually by a human being and the correlation between f/stop and exposure is quite arbitrary since the aperture is unknown. Bodes well for great photography, in other words.

Here are the keepers of the first roll I shot.

 
 

Thoughts on improvements of the design

The reason I picked aluminium foil was to have as thin a material as possible. I had read that if the thickness of the material approaches of the diameter of the hole, there is a risk of diffraction. Given the quality of the results that probably won’t matter, some may say, and you would be right. That said it, a slightly sturdier material than aluminium foil is probably a good idea. I experimented with aluminium from an Nespresso capsule and think that might be the next thing to use.

I think the hole was too big on this camera. A smaller hole, subject to the above bit about diffraction, would likely result in sharper images.

Lastly, I should look for an old Hasselblad magazine to simplify advancing the film, or find another manufacturer’s film magazines that permit winding the film. Or I should design my own film holder.