Making a Medium or Large Format DIY Box Camera

Editors Note: After I recently posted Alan's beautiful lumen photograph of The Dog Walker and the homemade camera that he took it with, I had requests for more info on the camera and how it was built. Alan graciously sent a very nicely done illustrated article on how he built his unique camera!

Thank you Alan, absolutely brilliant camera and photo as well as sage advice!

The last image shown is Alan's most recent lumen exposure of the Cool Fox mural taken with this camera. It's a dry exposure on expired Kodabrome paper. I remain amazed at the resolution that Alan gets with this process.

Making a Medium or Large Format DIY Box Camera

The following rough guide is all about and shows the large format camera I made using scrap wood and surplus materials in one afternoon. This was for producing 5” x 5” lumen photographs. It is also possible with care and loading/unloading in a changing bag or darkroom, that it could be used for regular non-lumen exposures with fresh photo paper.

I put numbered paper squares in each photo to make it clear what design considerations were made at each step as described in the text. This guide is not going to provide measurements, simply because they will vary so much according to what lens you choose to work with, and the negative size chosen.

It is always worth making a cardboard version initially, so you understand all the principles and iron out problems. If the carboard version is good enough, you may not even need or want to make a permanent wooden camera… just look after the cardboard one and treat it with care so it lasts. A well-made carboard camera is better than a badly made wooden one!

1: Overall front view of finished 5” x 5” camera showing the Carl Zeiss 135mm large format lens I used. Important: I tested the lens to find out what its coverage on a negative would be by using white paper held behind the lens and pointing it at a large window from inside my house. I got a sharp image that covered 5” x 5” so chose that for my negative size. At the same time I could measure the ‘focal flange distance’ also known as ‘register distance’. This is the distance between negative and rear of lens when infinity focus is achieved.

2: Rear view of completed camera showing hinged rear door for focussing screen, spirit level to help in setting up the camera and hinged lid to give access for loading paper. Virtually everything used was scrap or surplus items I had kicking around. I wanted to prove the ‘make’ does not depend on high level skills or having deep pockets to buy expensive items or tools. The lens was a cheap Ebay find because the glass has deteriorated with age. I have had it for many years and barely used it.

3: Rear door open showing ground glass focusing screen set well inside the camera body. I used scrap glass and went on Youtube to find out how to grind it myself. This is where I had to buy silicon carbide grinding powder in 400 and 600 grades (the most expensive part of the build but still cheap). I will probably never use up my two small bags unless I make screens for friends etc. Note: As focusing screens you can use good quality tracing paper in a cardboard camera and even sand clear acrylic sheeting with ultra fine wet and dry paper too.

The ground side of the glass faces to the back of the camera. In bright light I found a dark cloth is needed over my head and the camera to help see the screen better. If your eyesight is really good you may manage without but I’d have a cloth or T shirt handy to be sure.

4: The business end of the camera! This is the most critical part of the build, making sure the ground glass screen is set exactly right to enable a sharply focussed image with the lens set at infinity focus. The lens must be securely fixed in place centrally on the front of the camera to do this well. I moved the ground glass until I found the exact right place and marked where I would fix thin wooden beads to support the glass. In this case the distance was around 4” or 100mm. I fixed the glass using acrylic sealant (the sort you would use around window frames etc.)

5. It is always difficult to secure the paper negative so I made a box from stiff card to hold the paper negative securely and make loading/unloading a whole lot easier. This box fills the front section of the camera snugly so nothing flops around. I also cut a black card that folded over the back of the paper negative and the back of the box to make things foolproof. If you want to wet your paper you will need to make this card waterproof in some way. You will also have the advantage of stopping the ground glass screen getting wet. I made sure there was a 6mm/quarter inch small flange on the back of the box, so the paper negative had something to rest against and trap it in place.

6. When setting up the camera to take a lumen photograph, I usually remove the negative holder box, put the hinged lid down and open the back of the camera. I will take plenty of time ensuring everything is in focus and the camera is level and secure. Then I add my pre-cut expired photo paper (emulsion side facing the lens), put down the lid and close the rear door. From this point on everything is governed by the unpredictable lumen magic and whether things will work how you hope!

7: Everything must be made to ensure you avoid light leaks. I used some shaped wooden beads on top of the camera body, and the hinged lid was covered in thick black fabric that makes a tight seal once catches are engaged. The folded black card behind the paper negative gives an additional light seal in case any light leaks come from the rear of the ground glass. It is also well worth painting everything inside the camera with matt black paint to stop reflections.

8: Another view showing how all the design elements fit together. In all honesty, describing the build feels a bit like trying to answer the question “How long’s a piece of string?” There are so many variables such as any of the following:

• What lens do you have available?

• What materials, tools or budget do you have?

• What negative size will I use? (3” x 3” or even slightly smaller still gives excellent results)

• Will I go for medium format using a fixed focus lens from a broken 6x9 or 6x6 camera or try a large format?

The questions are many but what I do know is this; I made a working camera for lumen photography from scrap materials, a little bit of prior knowledge and a few YouTube videos. It has been a great experience doing it and I highly recommend that people have a go. I started with a much smaller fixed focus DIY wooden camera using a lens from a broken 1950’s Ilford Envoy. I checked the lens coverage on white paper and set everything up and built it, tested it, and found it worked well. My skills are nothing special and the main attributes needed are learning from mistakes, patience and willingness to adapt other people’s ideas.

9: My latest lumen photo on 5” x 5” dry negative using very, very old Kodak Kodabrome paper. No amazing colour changes but I still like it. My first lumens were done in a rough and ready, taped together cardboard camera using tracing paper as a focusing screen. I did much of my learning on that first as I would have been a bit crushed if I had made a wooden version that wouldn’t work and needed huge amounts of alterations!

One great advantage with a fairly heavy wooden camera is its stability in windy conditions. The flipside of this is being no fun having to carry it any great distance.

Final thoughts:

Please forgive the fact that this is not a belt and braces ‘how to’ guide with measurements and drawings. There are far too many variables to do that and in some ways is not a good approach anyway.

Recently, I posted some photos of cyanotypes I did using acetate negatives on a photography site. They were popular and someone asked if I could tell him exactly how to do the cyanotype process. I replied, “Do your own basic research and I’ll help fill in any gaps or overcome problems arising”. I never heard from him again. I wasn’t being mean spirited; I just didn’t want him to lose out on finding out things himself first from a range of sources.

One of the best things in learning anything new is getting immersed in the process and ‘owning the understanding’. If someone tells you exactly how to do something they have taken away from you so much of the precious discovery learning. I wish anyone doing one of these self-builds the best of luck and learning and I’m always happy to share what I know as very many others have for me.

All the best

Alan