This is a instant ferrotype camera. Circa 1931. (60 dollars in 1931 equates to 885.82 in 2011)           Note the copy stand used in photographing the negative to make a positive. (in the two step process)


Ever since I first saw this kind of camera on a family trip to mexico, I’ve been fascinated with both the process it utilizes and the ghostly images it produces.

As far as I can tell from 20 plus hours of serious web research in multiple languages, the original form of this camera came into being around 1909-1910 in the form of the Ferrotype “instant” camera.   These cameras were sold to individuals so they could make money by taking pictures of people on the street or at the beach or wherever people congregate.  The ferrotype process was very easy to use, you would make an exposure on a special ferrotype paper and simply drop it into a single tank of chemicals, then rinse the print in water and hand the resulting positive print to your customer.

Sometime around 1950 the commercially made “minute” cameras switched to a two stage process in which the photographer would make an exposure  on regular printing paper, producing a paper negative.  Then the photographer would take a photo of the negative, producing a positive print.   The reason for the change was probably because the ferrotype paper became unavailable or because the two step process produced a better looking print.

(The ferrotype process notoriously produced grey prints lacking in contrast.)

A description of the paper negative instant photo process form July 1937.


This youtube video explains the basic operation of the “minute” camera.

 (WordPress is not letting me embed a video, sorry.)

After my fist blog post on this subject, I was contacted by Lukas Birk, the founder of the Afghan Box Camera Project, at the time he was putting together a manual on how to build them.  He has recently finished that manual.

Since his construction manual is finished, I’ve decided to start building one of these rare cameras.  Now when I say build, I really mean design, then subcontract the actual construction out to an skilled woodworker and more than likely a CNC controlled router.

This is a very easy to build version of this camera. I’m sure it gives adequate results, but I plan to massively over-engineer the one I build. Image is courtesy of Landry Dunand

The “minute” cameras come in two basic varieties.  Internal focusing and external focusing.  Image courtesy of the Afghan Box Camera Project.

I have decided to go with the Internal focus, it’s more difficult to construct, but should be much more resistant to damage and normal wear and tear.   I should mention that I am constructing this camera under the (hopefully pretend) assumption that it will be my only means of income, so I plan to make it as bulletproof as possible.  Im doing this because I want to make the finest camera I can, and because I’ve lived off the proceeds of my polaroid 110b before, and I know life can be a funny thing, so I might indeed need to live off this camera if my life makes an unforeseeable left turn.  Hmmn….I suppose deep down, the real reason Im building this camera is to make a gris-gris against absolute poverty, but I would never admit that to anyone.  (maybe I shouldn’t have written that….)  Anyway, after deciding on what kind of focusing mechanism to use, the next thing I need to do is find a suitable lens for my soon to be camera.

A lens with a central shutter is almost a whole camera, all you need to add is a light tight box and a way to hold the imaging material (and a way to focus if you want) and boom, camera.

You should always build a camera around its lens (and shutter.)  After calling several camera stores and not finding anything that enthused me, I took a look in my camera closet (everybody has a closet full of camera’s right?) and I found two eminently suitable lenses.  A medium format Mamiya 80mm f2.8 covering a 6by6 cm square and a Kodak Ektar 127mm f4.7 covering a 4by5 inch area.

At this point I remembered some keen observations (rule #4 specifically) made by Paul C. Pottash (a man with experience in these matters)

1. It is best to have 3 trays inside the camera so that you can use a stop bath and avoid exhausting the hypo prematurely.

2. Remember that a camera filled with chemicals is not very portable unless you have some means of covering the trays to keep them from spilling when you want to move the camera without removing the chemicals and setting everything up again.

3. Most photographic papers are very unforgiving to exposure errors.

4. Don’t make the camera too heavy or complicated or the paper negatives and prints too big.

5. A “close up” lens is more convenient in use than a one to one extension of the bellows.

6. Don’t get your “peep hole” and safe light apertures too big.

7. Use some kind of hypo eliminator for the final wash and resin coated paper.

8. Always use a cable release.

After re-reading his comment I’ve decided to go with the 80mm f2.8 lens for a couple of reasons.

1. Its a stop and a half faster than the 127mm f4.7, this will allow me to have a much brighter image on the ground glass, making it easy to focus and of course allowing me to take photos in less light than the 127mm.

2. Its lens to film distance during a 1 to 1 enlargement is 160 mm vs. 254mm for the 127mm lens.  (Update, I’ve completely flip-flopped and decided to use the 127mm Ektar.)

The formula for this is, [distance between rear lens element and film]= f*(1+M) where f is the lenses focal length and M is the magnification desired.

To make a positive print you have to take a photo of the negative at a 1 to 1 magnification. So the 1:1 distance between the lens and film determines the minimum size of the “minute” camera I wish to build. (Diagram by Juan Carlos Franco.)

 3.  The 80mm f2.8 will allow me to build a smaller camera around a 6by6 cm negative and produce a 6by6 cm print.   Since I am producing a square image I dont need the complicated turning mechanism needed to change the negative from a horizontal orientation into a vertical one. Like the one seen in the picture below.

You would grasp the ground glass and rotate the whole assembly left or right.

Instead I can sandwich the paper negative between a metal mask and the copy stand to crop the image when I take a picture of the negative to produce a positive.  See image below.

A little plain and workaday

Now were getting somewhere, this one has some class.

Plain, but the copy stand is constructed in an interesting way.

After all that online searching I believe I have found the design I want to recreate.

This video shows the camera I plan to base my own version on.

(WordPress is not letting me embed a video, sorry.  Please do watch the first three minutes.)

Its the most beautiful “minute” camera I’ve ever seen.

It uses rods and linkages to allow many of its functions to be utilized by turning levers. Which is awesome.

Notice the two hanging chemical trays, one is developer, the other the fixer.

I plan to use this technique to make the ground glass.

There are a few things I still need to figure out. 

 1.  How to construct the ground glass/paper holder.

2.  How to make the ground glass/paper holder move smoothly back and forth to focus while retaining its vertical and horizontal alignment with the lens.

3.  Since I want to be able to shoot this camera untill the day they stop making photo paper it has to be able to handle Ilford multigrade paper.  I’ll have to include a way to mount an Ilford multigrade filter directly behind the lens.  This would allow me to fully control the contrast of the resulting image. (I am betting on the fact that Ilford multigrade will probably be the last photo paper made, hopefully that will be many decades away, hopefully.)

4. Probably a few hundred more problems that will only become evident when I start building the camera.

Ilford currently makes both graded paper and a direct positive paper.