Christopher
Stoll

Polaroid SX-70 Switch Sequence

Polaroid SX-70 Switch Sequence

I have recently been troubleshooting some faulty Polaroid SX-70s and I found myself reading back and forth through the repair manual to find the right switch to troubleshoot. So, I decided to create a set of images to help visualize the sequence of steps required to make a photograph with an SX-70. I find it easier to scroll through the steps, or swipe through the steps (clicking on an image enlarges it and allows for swiping or arrowing left and right).

For the camera I was troubleshooting when I made these images, switch 3 was dirty and a little corroded. With S3 not functioning properly the exposure was effectively stuck mid-cycle, the shutter would close and nothing else would happen. After cleaning the drivetrain and the drivetrain switches (S3 and S5) the camera operated normally again.


Iraq War Deployment Experience, 2003-2005

Iraq War Deployment Experience, 2003-2005

A year and a half after I arrived back stateside from my expedition to Iraq I was asked about my deployment experience. The child of a friend of a friend needed to interview veterans for a project they were working on, so I agreed. The thing I remembered about my response, and what made me think of this questionnaire many years latter, was my memory of how Iraq smelled. Usually memories are visual, but these memories had an olfactory component to them. This was brought back to mind by Jon Stewart’s recent efforts to highlight the ill effects veterans are suffering from burning shit in Iraq.

At our first forward operating base we had burn toilets prior to receiving chemical toilets, but I think the rear elements had to burn the waste while we were out running missions. The thing people probably don’t realize though is that the baseline pollution level in Iraq, the baseline in combat zones, is considerably higher than what we enjoy here in the United States. Perhaps urban air quality in the late 60s, prior to the EPA, was similar to what I experienced in Iraq.

Of course it may have been worse in Iraq due to the dusty, arid environment. There was always something in the air. We lived in an old government building which perhaps contained asbestos, who knows, I doubt anyone tested for that. What we do know is that the building was famously bombed by Tomahawk missiles on the first night of the war. Those missiles were probably tipped with depleted uranium. We would laugh every time a mortar bounced off of the sturdy building. But, the so-called insurgents might get the last laugh; each of those mortar hits would stir up dust in the unventilated building. The Army should have given us N95 masks rather than gas masks which literally went unused, because, you know, there were in fact no weapons of mass destruction in Iraq.


Fogged Film: 1990 Vericolor III & 400

Fogged Film: 1990 Vericolor III & 400

Lately I have been experimenting with expired film. I have a variety of expired film stocks, but I started with a couple rolls of expired Tri-x since black and white film usually has more latitude than color film. Having gotten a feel for how expired black and white film responds, I was ready to try color. I have about a dozen rolls of both Vericolor III (VPS) and Vericolor 400 (VPH), so those are the two color films I choose to started with.

My experiments with high-speed black and white film seemed to validate the rule of thumb that calls for overexposing film one stop for each decade it has been expired. Kodak Vericolor 400 is a high speed color film, so it would need at least the same amount of compensation. The roll expired in March of 1990, so as a baseline I treated it as an ISO 50 film. The box speed for Vericolor III is 160. Since the emulsion is less sensitive it should degrade somewhat slower than the more sensitive emulsions. I used ISO 40 as a baseline for it, it also expired in March of 1990.


Fogged Film: 1976 Tri-X, Part II

Fogged Film: 1976 Tri-X, Part II

The last time I shot very expired Tri-X, I tried to use it as if it were new. I primarily shot it at box speed, with just a quick test of overexposure. I had read that expired film should be overexposed, and it makes sense that exposure compensation is needed to account for increasing base fog, but I was curious how the rule-of-thumb applied to Tri-X. From the perspective of someone who knows little about film chemistry, there seem to be at least two dimensions that need to be considered when deciding how to compensate an expired roll of film. First, it seems fair to assume that color film might degrade faster than black and white film due to the additional chemical complexity of those films. Second, it seems reasonable to assume that original box speed will impact how fast a film will degrade. So, I wasn’t sure if the rule of thumb to overexpose one stop for each decade a film is expired applied to Tri-X. After processing the last roll of expired Tri-X, it was clear that 45-plus year old Tri-X needed at least two stops of over exposure.


Fogged Film: 1976 Tri-X, Part I

Fogged Film: 1976 Tri-X, Part I

I recently came across a large lot of expired 120 film. The lot included a variety of black and white and color films with a wide range of expiration dates, and the price per roll was a fraction of the cost of new film. I snatched it up. The idea is to perform some informal experiments to see how various films have held up over time, the unknown storage condition notwithstanding, and to test some common axioms used when shooting expired film.

One of the axioms that I want to test, perhaps the only one, is that it is necessary to add one stop for each decade a film has been expired. I have looked for a formula or chart that would help me understand how the base density of film increases over time, but I was unable to find one. Kodak provides some information regarding film degradation in their film storage guidelines, but nothing about the rate of decay due to gamma radiation or negligent storage. So as I use this lot of film I will be looking to corroborate that maxim.


Photography Practice: Summit Parks

Photography Practice: Summit Parks

Practice seems like the way to get better at activities, so I thought I’d apply that thinking to film photography. I would quickly get bored with practicing if I was just taking pictures of things around my neighborhood, so I have given myself little projects to get out and shoot. As an added bonus these projects help me shake of the COVID blues, get out of the house, and visit local places which I may never have visited. My first assignment was making interesting images at our local parks.

There are a lot of parks in Summit County Ohio, which would be surprising if you knew how densely populated the area once was. Taking pictures at parks requires little planning, just turn up, find something interesting, and take the photos. Another benefit of taking photos at parks in Summit County is that most lack obvious photographic vistas. So, locations must be scouted, which requires a lot of walking around and paying attention to nature.


Found Film: Kodak Tri-X from a Pigeon

Found Film: Kodak Tri-X from a Pigeon

I found this very old roll of exposed Kodak Tri-x film in a Shinano Pigeon II camera, and I decided to develop it. I think that perhaps the only reason it survived is because no one could figure out how to open the back on the camera. The back doesn’t swing open like other cameras of this vintage, it detaches down in the same way a Leica back does. Though I’m somewhat satisfied that can explain why no one else removed the film from the camera, I’m curious why the original owner never did. Maybe after taking 8 mundane photos they decided that photography wasn’t for them – but they didn’t have the film developed to see how mundane they were, so the simple explanation is probably not the correct one.


Five Success Factors for Computer Vision Projects

Five Success Factors for Computer Vision Projects

Recent break throughs in neural networks have made the use of computer vision technologies available to a wider audience, and many businesses are looking for ways to apply those technologies. To address the demand, large cloud service providers now providing basic turn-key computer vision services. Computer vision solutions currently perform best when they are asked to do tasks which are limited in scope. So, unless pre-trained models are already available for the task at hand, there could be a steep cost to implementing computer vision.

To make things worse, there are relatively few people who understand computer vision technologies from a wholistic perspective. This dearth of experience is not due to lack of educational resources, rather it is due to the steep learning curve and the inverse distribution of educational materials. There are many ways to learn how to get started with a computer vision project, but there are fewer resources explaining how to apply those initial learnings to harder real world problems.

Due to those challenges, it can be hard for technology managers get the information they need to make informed decision about the implementation of computer vision systems. In this post I will discuss ways to avoid some of the common problems encountered when non-tech companies attempt to implement custom computer vision solutions.