I have been interested in film photography and vintage cameras ever since I took Bill Kuhns B&W photography class at Nathan Hale High School in Seattle, WA. I enjoyed the class so much that took it all four years of high school and by the end I was maintaining pretty much all the photographic equipment. Although that was years ago, I still have a large collection of vintage cameras which I have repaired / restored and I enjoy shooting them from time to time. That is easier said then done for some, however, because of film that is no longer available. One in particular, a Kodak Flash Bantam, which was a gift from my dearly departed grandmother, was the inspiration for the project described in this article. The Kodak Flash Bantam is pictured below.
(Photo credit Pacific Rim Camera)
The Flash Bantam, like the rest of the Kodak Bantam series, uses type 828 photographic film, an obsolete format which hasn’t been produced by Kodak since 1985. This leaves a collector with a series of options, none of which are terribly good:
- Buy expired 828 film off of eBay and try to use it. This might have worked years ago, but since the last fresh stock is from 1985, and since most of it is Kodachrome which can no longer be processed, this really isn’t going to work well.
- Buy 828 film from Film For Classics. This is a good option which I have used in the past. The film can be bought directly from B&H Photo Video, it is black and white (which is good because you can process it at home), and it is of good quality. The problems are as follows. First, the film is expensive at $14/roll, but more importantly it doesn’t have the perforations (index holes), one per frame, which align each shot in the camera and prevent double exposures. As a result, many of my pictures were ruined.
- Buy expired 828 film off of eBay and respool it with fresh film. There is an excellent discussion of this process at bnphoto.org and another one here. There are three sources for film for this process. The easiest is to use ordinary 35mm film (828 is 35mm wide) but the sprocket holes will cut into the edges of the pictures as shown here. The sprocket holes can also interfere with the mechanism intended for the holes in 828, requiring that it be disabled somehow. Another option is to cut down 120 roll film. However, to do this well you would need to build a film slitter. The last option is to buy unperforated 35mm film, a format made for professional portrait photography. The article at bnphoto.org lists several sources for unperforated 35mm film, but all are color emulsions, not B&W. Of course, none of these sources for film will give you proper 828 index holes.
Of these three options, I think that the last is the most appealing as it has the potential to provide an inexpensive source of 828 film. I thus decided that I would build a device which could create strips of properly sized and perforated 828 film. The plan is to make and sell these inexpensive strips of film so that other ambitious camera collectors can respool their own rolls of 828. Aside from my strips of film, the only expense would be the one-time investment of an expired roll of 828 for the backing paper and spool, or else, if they have a spool, they can make their own backing paper from a roll of 120 as described in the respooling articles linked above.
Being the perfectionist that I am, I wanted my device to produce a strip of 828 film with the PRECISE dimensions of an original Kodak roll. When I couldn’t find the original specification anywhere, I decided that I would have to buy an expired roll of film and measure it. After a bit of hunting on eBay, I found an old roll of Kodachrome 828 which had obviously (from the auction pictures) been totally exposed to daylight. This seemed a fitting roll to sacrifice so I bought it.
After a couple hours with a dial caliper, I was able to produce an accurate drawing of the 828 film format. This drawing is shown below and is also available in PDF format. Note that the drawing shows the film with the emulsion facing down.
Now knowing the dimensions, I set about trying to figure out how to make a device which would cut the film appropriately. I quickly realized that there are three separate operations that need to be performed:
- Cut the film to width (if using 120 film)
- Cut the film to length
- Punch the index holes (perforations)
At first I wanted to build a film slitter which would simultaneously perform all three, but I quickly realized that this was too complex for me to easily fabricate and I was not sure how a rotary device would assure proper spacing the the holes. Thus, I settled on separating the slitting device from the punching device. Besides being easier to build this plan was advantageous because it would allow the slitting device to make film of other formats that needed unperforated 35mm film (like 126 for example) and it would allow the punching device to be used on commercial unperforated 35mm stock.
Since I am still hopeful that I will find a commercial source of unperforated 35mm black and white film, I decided to start by making the film punch. Figuring out how to make this device, however, was not so easy. First, the punch itself needs to be tiny (2mm x 2.3mm) and precise. Second, the spacing between the holes needs to be set accurately. After much thought I realized that I could use the Minitch Machinery Corp Mini-Mill/2 desktop CNC milling machine at work to make the punch and its corresponding die hole. That left the question of how to space the holes accurately. Since there are 8 holes in the standard length 828 roll, I first thought that I might build a device with 8 separate punches. However, I realized that this would make the entire device excessively complex and too large to use conveniently in a changing bag, plus it would prevent making strips of film with more then 8 holes. I then thought of making a device with a wheel to measure the distance between the holes. This concept, however, was complex to execute and I was not sure of its accuracy. Finally, with the help of a close friend, I realized that after I punched the first hole, I could use a ball detent mechanism to place it a precise distance away from the punch and thus punch the next hole accurately! Repeating this process would thus allow each hole to be punched in the correct location. What’s more, I could use the edges of the slitting device to make the leader and tail of the film the correct lengths.
With this design in mind, I set about creating the device. After a couple false starts and some wasted stock I was eventually able to make a device that worked very nicely. One of the most important realizations was that commercial ball detent devices will not work well in this application. The commercial devices I tried were imprecise in that the balls were not held tightly against lateral movement. They also didn’t allow the ball to protrude far enough from their ends, and the spring pressures tended to be too high. Thus I had to make my own. Once that was solved, the rest mostly fell into place. The finished punch is pictured below:
The device is operated in total darkness (and while wearing cotton gloves) as follows:
- Insert the film into side A, emulsion side down, until it is flush with aluminum base on side B.
- Depress the punch knob firmly until it clicks, then release it.
- Advance the film toward side B until it ‘clicks’ into place – this is the ball detent mechanism finding the hole.
- Repeat steps 2 and 3 for a total of 8 holes.
- Using scissors, cut off excess film so that it is exactly flush with the aluminum base on side A.
- Remove the film from the punch and respool it with backing paper onto spool.
Note that all these steps can be done by feel.
I carefully designed the film path to assure that all the parts that touch the film are smooth plastic (note the yellow tape over the aluminum base) and that there are no sharp edges on on the ball detent device or the retracted punch. The photo below shows the inner workings of the device
I verified the accuracy of the device by feeding my reference roll of 828 film through it and verifying that the punch lines up exactly with each hole. I have also verified the correct operation of the punching mechanism by punching holes in scraps of 35mm film. The photo below shows this sample roll in the punch.
As the project stands now, I have verified that the punch work correctly, but I do not yet have a source for unperforated 35mm B&W film to use in it, so I can’t yet sell 828 film for respooling. If you have any leads on where I might be able to buy some, please let me know. Else, if I strike out on that front (or maybe even if I do find a source) the next step will be to produce a precision film slitter to cut down 120 roll film to 35mm width. If this all works out well, and the strips of 828 film I produce sell well, my next step will be to make a similar punch for type 126 film. In any case, stay tuned.
Finally, I have started a thread about this project at apug.org. Check it out for some more information and feedback from other readers.
As much as I would love to make these devices available to anyone who wants one, I will not be selling them on the open market – I don’t have the facilities to produce these in any kind of quantity. However, if you have access to a machine shop and you want to build this device yourself, I am releasing the full design here. This document includes a complete parts list, a complete set measured drawings, machining instructions, and assembly instructions. Note that it is available for PERSONAL, NON-COMMERCIAL USE ONLY. In short, you are welcome to use the plans to build the punch yourself, but you must contact me to work out a commission if you wish to sell either the punches or a significant fraction of the film produced with them.