Sunday, July 21, 2019

Quality assurance, user experience testing and some minor modifications.

The camera I made to redo the pictures in the 10th Anniversary Populist Plans was 45mm from pinhole to film, 6x6cm format with a .31mm pinhole. I didn’t mention it in that post but there were a couple things I did differently, and they needed testing. In any event, you just can't build a camera and not run some film through it. It turns out I learned a lot.

I usually lightproof a camera with black spray paint or opaque photographic tape. Everyone doesn't have those options, so I’ve included a piece on the template to make a double layer in the back of the camera to ensure that it’s opaque. There's a similar piece to lightproof the front, which also serves as a removable mount for the pinhole. I’ve never used the extra layer in the back and when I did use the pinhole mount, I’ve never depended on it to make the camera light proof. I didn't do any other lightproofing on this camera other than the extra layer from the template. I’d better find out if it works.

I rode my bike to Menomonie Park to do some quality control and user experience testing. The first frame was this concrete bunker that has something to do with the city water supply. The railing was full of birds when I first stopped but by the time I was ready for the exposure only one was left. Seems like the camera works well. However, it wasn’t a particularly bright day and I’ve been fooled by that before.

To give it a more analytical test, I advanced directly past one frame and then left the camera out in full sun for a day and a half on the next one. Looking at those two frames I can hardly tell the difference. There is a little bit of a fogged spot on that second frame but if it was overlaid on a negative, I don’t think I would have noticed.

Looks like the extra light proofing layer is a workable solution. (There’s already a double layer everywhere else.) 

I went out again on a completely clear day with brilliant sun.

After I had taken one picture, I decided to try to get some shots with the Manic Expression Cube. In my haste switching cameras, I forgot to wind the film. I realized what I had done but when I got back to my bike, I noticed when I had put the new camera on the bike rack the shutter had come open and ruined the picture.

User tip #1: When you’re not actually taking a picture, use one of the rubber bands to secure the shutters, especially if you’re going to be bouncing around on a bike. It seems I have to relearn this lesson at some point every year.

The picture that got ruined was in the shade with an exposure of 5 seconds. When reshooting it, I looked up from the timer on my phone and noticed that the shutter was kind of loose and had slipped back down a little covering the pinhole. You can see this in the double exposure above as well.

That prompted the first modification. I glued a few small pieces of cardstock behind the shutter to make it a little tighter and add some friction. At first I made it a little too tight. I could still open and close it, but you don’t want to have to use so much force that you move the camera when you open the shutter. In order to get the pressure just right, I had to split a piece of my cardstock. It’s not too sticky to open now and stays up when making an exposure. 

If you notice the shutter is a little loose after making it, another solution is to mount it on the camera so it slides out to the side instead of up and down.

My next stop was the maintenance shop a little farther along.

User tip #2: If you’re bouncing along on a bicycle, retighten the film so it’s flat in the back of the camera before making your next exposure. Although this sort of random curve is sometimes seen as charming.

The little gazebo at the south end of Miller's Bay was my next subject.

While I was taking this, there was a car full of people parked right across from it, just sitting there the whole time. Being watched while I take pinhole pictures always makes me a little nervous. When I went back and attached the camera and tripod to the bike rack, I didn’t notice that my front wheel was facing nearly backward, and when I turned to grab for the handlebars, the bike fell over away from me. Leaning forward to catch it, I went over with it, right on top of the camera. My dignity didn't survive but other than getting a little wrinkle, the camera was still intact.

I once bragged that my cameras could probably survive a fall off a ten story building without exposing the film. Having an oafish old man fall directly on it is at least as much force.

I couldn't tell if the frame in the image chamber got exposed by my fall. The next exposure was of the little concession stand. It’s on the shady side of the building and the exposure was over a minute. Although everything in the picture was in the shade, until I opened the shutter, I hadn’t noticed that the sun was shining over the building directly on the pinhole. What I got was a lot of very overexposed flare bouncing off the edge of the pinhole.

That’s also often seen as charming. Today I saw an ad for an app that would add lens flare to an image “for dramatic effect.” I’m a little old-fashioned and I hate flare. Sometimes you get some interesting diffraction effect but most of the time it’s impossible to distinguish between flare and a light leak. My biggest mistake the last time I did a workshop was failing to warn the participants not to face into the sun when making a picture. I couldn’t tell whether that was the problem or if they needed work on their cameras. 

With a wide angle camera like this you almost have to face away from the sun to make sure it’s not reflecting off the edge of the pinhole.

One way to control this a little is to tarnish the pinhole with liver of sulphur, but you can guess what that smells like. 

A common approach with a lens is to make a hood to prevent the sun from shining on it in the first place. I can’t say I’ve ever seen a pinhole camera with a hood around the pinhole.

The solution, of course, is more cardboard. I didn’t want to create something that was flimsy and might get bent or crushed as the camera tumbled in a backpack, so I made my hood by laminating layers of card stock around the pinhole hole opening. It’s easy to tell when you’ve gotten enough layers because you can just look from inside the camera and see if the pinhole is still unobstructed. That turned out to be six layers of cardboard with this camera. 

After I had made the hood, I set up a few compositions facing the sun, even in one case where I had the camera tilted up a bit. The sun is shining on the front of the camera in all three cases but the pinhole itself is shaded. I've just developed that film and it seems to have worked. (Later edit: The results at this link)

After the concession stand, I continued on to the beach house with the sun at my back. It appears that the camera survived the fall with it’s opacity intact.

One other change was using black duct tape to make the smooth edge over the dividers of the image chamber the film rides over. I generally don’t like using it because it’s hard to cut or tear really accurately. It’s a little shiny, kind of thick and not particularly repositionable. I’ve always had opaque black photographic tape around that works really well but black duct tape is opaque, almost universally available, and comes in small rolls. I also taped down the pinhole with it. It worked fine. I think regular black masking tape would work as well for this purpose.

The film for this test was 100. As if I wasn't experimenting enough, I used stand development with Rodinal 1:100 for the first time and that seems to have worked OK as well.

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