Saturday, October 2, 2021

Lessons with the 4x5 Pinhole Lab Camera


The next project with the double-sided adhesive and the self-adhesive labels was the big guy, the 4x5 Pinhole Lab Camera, with the latest corrections to the template. This camera is supposed to be all about learning and it did not disappoint. 

It has slots in the interior so you can change the angle of view and the pinholes - under light-safe conditions for your light-sensitive material i.e. a darkroom or a changing bag. It has three pinholes for rising and falling front capabilities in both the horizontal and vertical orientations.

The main change was to the shutter. In the last iteration, at the shortest distance to pinhole, the shutter got in the way of the edges of the image. I changed the distance between the pinholes from 15mm to 20mm and enlarged the openings. As you'll see below, that seems to have worked. Notice how wonderfully straight that new shutter is on the box.

I made two near-fatal mistakes in making it. Cutting out the top box, instead of cutting between the side and the side flap, I almost cut off the flap. I caught myself before it was completely severed. I repaired it with three layers of opaque tape and proceeded normally. It left an unsightly gap in the corner so I glued in a narrow strip of card to fill it.

When I made the top, with it formed over the bottom for the best fit, I was so focused on that damaged corner, I didn't notice that the holes for the pinholes were on opposite sides. No big deal, right? When I just opened it and reversed the top, I discovered that it was very slightly trapezoidal and the outside front was just a smidge narrower than the bottom. It would slide over it but it caused the inside to bow in, including moving the pinholes farther back. I cut a narrow triangle out of the front of the inside box so it fit correctly without distorting it.

All the struggling to figure this out didn't do any good to the front of the inside box, and it would still bow in more than I wanted. I glued in a wedge at the top of the outside box so it would force the front of the inside up against the outside. The inside corner of the front opening kept catching on the bottom and had to be cut off. 

The top and the bottom are only the template and one layer of the cardstock so to make it more opaque on those sides, I added a second layer of the cardstock. I don't know if that was enough which I'll explain in a minute.

For finders, I punched little circles out of a double layer of white cardstock with double stick carpet tape on the bottom. This sort of cardstock has a tendency to delaminate, so they're covered with a layer of glue. Since the camera might be used in any orientation, they're on all four sides.

I made three sets of pinholes at .27mm, .36mm, and .45mm, sizes near optimal for the first three slots. I just decided to use the .45s for the six inch distance. That makes working with these about f150 at the one and a half inch slot, f200 for the three inch, f250 for the four and a half inch, and f333 at the back of the camera at six inches. There are bumps on the top inside-facing side of the mounts so I could tell which was which in the changing bag. Of course you can use any size pinhole at any distance if you're not concerned about optimal diffraction.

To make it easier to change the paper and keep it flat at the image plane, I made a little frame so I could slide the paper in rather than taping it. That works very well. I made it to accomodate sheets of film (?!) which are just narrower than 5 inches so I had to trim each sheet to the right width.

The outside box has thumbholes so you can get a grip on the inside box but it would be easier if you could just grasp the whole box. I cut off the bottom inch that extends below the shutter and glued it to the inside box. That also reduced the amount of movement you need to make inside the changing bag, which as it turns out is a critical specification.

It has no tripod mount since it's intended to be used in any orientation and unscrewing it from the tripod every time to reload would be a hassle. I had been attaching the camera to a platform on the tripod with rubber bands. As you know if you ever shot one across a classroom, they can get away from you, possibly damage the camera and even accidentally open the shutter. On one of our Halloween hunting adventures, I bought some Velcro fastener straps. With a strip of that held to the platform by the quick-release adapter (one of these days I should staple it on), I could quickly and firmly-enough mount the camera on the tripod. It doesn't block my view of the viewfinders. That was a real improvement over the rubber bands.

To contain my paper,  I've been using this box from letter sized Photo Mechanical Transfer receiver paper which I've painted with numerous coats of black Krylon on the inside. I kept losing track of the pinhole mounts in the changing bag, so I taped an envelope on top the box for them.

I put the sheets of paper in some old envelopes to protect them a bit, with the emulsion side always facing up. I have a sheet of black cardstock just smaller than the box inside. Fresh sheets are on top, exposed are on the bottom.

It turns out it's kind of a tight fit in the changing bag.

Unbelievably overconfident, I set off to try it out at the County Park. Changing the paper, image plane and pinholes seemed to work pretty well. When they were developed, except for one, they were all very fogged!! After my experience with Little Guiness, I immediately suspected this cardstock to be less opaque. In kind of a knee-jerk reaction, I painted the inside with about six coats of flat black Krylon, After a few tests at home including a full day in the sun, it looked like the light-tightness of this camera could be trusted. 

Out to the County Park again, and yet again most of the images were fogged to some extent! I now realize that while wiggling around inside the changing bag, the sleeves kind of drooped down to my elbows and allowed some light in to ruin my negatives. I kind of became aware of this in that second field test. I did some more exposures at home changing in the darkroom and those support my hypothesis,

I'm going to make a paper safe out of foamcore just big enough to hold my envelopes and Sarah has said she will help me make the sleeves elastic so they stay put on my biceps. Another realization was that the times I've had no trouble in the changing bag, I had a winter coat on which fits more tightly in the sleeve. Maybe just wait til winter.

So, other than all that drama, how's it work? Keep in mind this also required a lot of relearning about the response of paper. They're also developed in Caffenol so couldn't exactly be developed by inspection.

From the first outing in the County Park.

At an inch an a half, the latest version of a playground merry-go-round. It's alway odd to see these ultra-wide angle images when you know where the camera actually was. I don't think I was two feet away from it. This is with the on-axis pinhole. Looks like the whole image area is lit up.

From the tests around the house.

At one and a half inches, on-axis at my new computer.

I wanted to know if the shutter got in the way at an inch and a half with the rising front. I figured the bright sky at the top would compensate for the extreme vignetting at this angle. Again no obstruction.

How about the rising front in the vertical orientation at an inch and a half. This time I chose the north side of the house to get an accurate assessment of the vignetting. There's some hope of getting a full frame image with a properly exposed negative but when you're underexposed to start with, the edges are hopeless. This does illustrate how the center of illumination shifts with the rising front.

From the second trip to the County Park.

The third base bleachers at the north softball field. This was about when I realized about the problem with the sleeves. With the on-axis pinhole at four and half inches.

The previous changes took place at a picnic table in the full sun although with the sleeve openings opposite the sun. For the next shot, I made a point of using a bench in the shade. This ping-pong table with the steel net was done at three inches with the axial pinhole.

I thought the light poles around the pavilion made for a good test with the rising pinhole at four and a half inches.

Back home, changing in the darkroom.

At f333 it's easy to underexpose an orange Jack-Be-Little pumpkin underneath a lot of foliage. The axial pinhole at six inches.

Another attempt at six inches.

With the camera set at four and half inches I walked around the corner to get what appears to no longer be the Glad Tidings Tabernacle with the rising pinhole in the vertical format.

And again playing with the rising front at an inch and a half, I thought the sunshine on the white house and sky would overpower the vignetting.

One of the justifications for large format is that you're more likely to take meticulous care with each negative. With one exception, all these scans are uncropped and unrotated. Looks like I came pretty close to framing things the way I wanted as well. Maybe I'm ready for the grown-up's light sensitive material.

Wednesday, September 22, 2021

Little Guinness' Victory Tour of the Fox Cities.

In the mid-90s, Race Office & Art Supply closed their retail store on Main Street. In their clearance sale, they had three rolls of 1 inch x 60 yard 3M #235 Opaque Photographic Tape for a dollar apiece. I snapped them up. There are still about a third of two rolls left. I used it to make darn sure Little Guinness was reliably light tight. Coincidentally, Camera Casino is now in that store.

Shortly after loading the camera, I achieved a goal I had been pursuing for years. Stewart is a typical sun-loving cat but he can hear a tripod coming from across the house. One morning he was obviously concentrating on chasing mousies in his sleep with an occasional twitch of his legs and extension of his claws. I approached as near as I dared, made as few adjustments to the tripod as possible and opened the shutter for a one minute exposure.

Unbelievably, no response to this. I boldly approached and readjusted the tripod. When I closed the shutter and wound the film he drowsily looked up and took off like a shot.

I had much better cooperation from the squirrel on the table.

Uh-oh! The police responded to an expletive-laden shouting match between a young couple a few doors down and across the street and they parked in front of our house!

A week or so before we had gone to Appleton to pick up my photo that had been in a juried show. We had lunch at Fratello's Waterfront Restaurant in a repurposed factory with its giant windows and panoramic views of the rapids and the dam over the Fox. I didn't have a camera with me but I was so taken by the scene that I went back with Little Guinness. They also have a restaurant on the Fox in Oshkosh with the same undistinguished menu but the building is new and the river isn't as dramatic upstream from Lake Winnebago.

We included a visit to the museum where the juried show had been to see an exhibit by the winners of last year's show. Spooky Boobs is a collective from Madison who very cleverly skewer the patriarchy with slickly designed graphics. They sell the posters in the gift shop.

The main gallery held an exhibit of pieces by local artists who had been commissioned by patrons of the museum. I had noticed in the juried show that some of the works had a statement that this artist was accepting commissions. Nobody asked me if I wanted to accept commissions.

We had recently ordered a footstool that turned out to be way out of scale for our modest bungalow. We could avoid repackaging it if we returned it in person at Marshalls in Appleton. The carton wouldn't fit in the Mustang but they didn't seem to mind taking it back without it. It took two clerks and a supervisor some time to figure out how to code a return of an on-line purchase so there was plenty of time for an exposure.

While we were there we took the opportunity for some Halloween hunting.

Halloween decorating has gotten to be quite creative and we stopped at several stores to see their offerings. A real expert could to tell you which store this is, but we couldn't remember witch was witch.

One place we hadn't planned on going was Kohl's. Sarah had seen a door mat on-line she was interested in but we hadn't looked up where it was until I took a wrong turn and we drove right up to it.

It's pretty easy to unobtrusively place a little box made from packaging on the shelves among the merchandise. Several shoppers looked at this little haunted house without noticing the camera sitting right in front of it.

We enjoyed our little day trip so much, we went back a week later. The Fox descends about 160 feet between Lake Winnebago and Green Bay. The river was lined with factories taking advantage of the falling water. In Appleton where the largest of the falls was, they've done a particularly good job of restoring and repurposing a lot of these mills. This one is right next to Fratello's. Just behind the tree is another smashing little restaurant, The River Tyme Bistro.

We were seated next to a large window in the shade of the tree. The decorating includes random artifacts casually placed around the room.

Just behind me was a little conversation nook with a microscope on the coffee table.

Unfortunately we were sitting in a largely empty dining room where to the left of the frame it looked like they were setting up for some kind of children's party. To the right there were about 25 well-appointed women at a meeting of a fund raising organization for abused women. They were watching a video of a cavalcade of speakers with the audio playing through what sounded like a pocket transister radio from the '60s. It kept going for the entire time we were there and some of the ladies looked a little envious when we left.

Just up the hill is a historic house that somehow we had never been aware of. It's the first house in the world to be electrified by hydro-electric power. It would have been the first house connected to an electrical distribution system rather than by it's own generator, but Edison wouldn't license them the technology until he had one set up in New York.

It was a very nice tour. No velvet ropes and lots of references to everyday sayings that trace back to the technology of the late 19th century. Most of the historic houses I've seen have converted the kitchen to offices or galleries, but this one was restored and still used to cater events.

There was only one other person on the tour and it was very friendly and personable. Sarah chatted with the docent while I took pictures on the porch.

The entire time the docent watched me and I even got involved in the conversation a few times, but he never mentioned anything about my cardboard camera.

We then drove down river to Little Chute. Just after the turn of the millenium, the city elders decided they needed to celebrate the Dutch heritage of the town and commissioned a full-sized, working windmill to be constructed in the Netherlands which was disassembled and reconstructed on the Fox in the middle of down town.

Little Guinness chalked up another notable feat when I went for the backlighting and captured the famous black hole sun effect, where it's so overexposed it gets solarized.

Little Guinness has a .17mm hand-drilled pinhole 24mm from a 24x36mm frame - and no light leaks.  Kodacolor 200.

Tripodology Note: I took about half of these with the little gag tripod Promaster sells for keychains.

Saturday, September 18, 2021

Before f295: The eleven camera experiment.

In the early 90s, I horned in on a class for teachers to learn how to use the planetarium. That led to teaching a two week, 70 minutes a day astronomy class in the summer to 4th through 7th graders who had been certified by their teachers as gifted. Pertinent to this blog, when the organizers of the program surveyed the teachers for ideas to expand the offerings, I suggested Pinhole Photography and they went for it. It occured four times between 2001 and 2006. I can't believe I had the energy to do these things. I remember them as a tremendous amount of work. But it is extremely cool to watch children learn.

My favorite activity took place just once, in 2005. (OK, historians, f295 had started the year before.) There were ten children in the class and an education major assigned to help me. 

We had already built cameras and had been taking photographs for a week.

I brought eleven cameras of different sizes, angles of view and curved and flat film planes. In the activity I had in mind each kid would take one camera and take a properly exposed picture of the planetarium from the same spot to see how the images changed. 

I specifically chose the view to show the change of the rendition of space and the distortion of lines of Halsey Science Center behind the planetarium. This was at about 9:30 am with trees still casting shadows on the planetarium.

The web page for it is still accessible at the Wayback Machine.

I'm surprised I was still using the refractionist term focal length.

To decide who used what camera, I lined the kids up by height and had the shortest one pick first. She was also the only 4th grader in the class and was kind of shy. Without hesitation, she picked the littlest one, the 35mm film canister.

My objective was to show how pinhole distance and image size determine angle of view and that if one camera was twice as big as another, they would have the same angle of view. I also wanted to illustrate the vignetting when the edge of the image was much farther from the center.

It turns out I still have most of these cameras.

With one exception, they all had .5mm pinholes drilled by completely piercing the brass with a #10 needle. Each camera had a table of exposures on it.

Cameras with flat film planes

4x5 camera of 5 inch focal length.

This was the camera we all had built and had been using. The one in the photo was built in a previous session by one of the older kids who took home the camera I had made instead of this one. He was a smart kid and got into it well enough, but he would have rather been playing football.

I learned how to make these cameras in a workshop with Ruth Thorne-Thomsen twenty years earlier.

4x5 camera of 10 inch focal length

I know I still have this camera somewhere. It was one of the three foamcore cameras I made for my own use. I made it so I could get close-up views of my south kitchen window without putting the tripod in the sink. This is a detail from a portrait of my cameras that was in The Pencil of Nature. Incidentally, this picture of the camera was done with the five inch camera above with the kid-drilled pinhole.  At ten inches it of course has half the angle of view and requires four times the exposure.

4x5 camera of 2.5 inch focal length.

This was another of the cameras I regularly used myself. Twice the angle of the five inch and with the same pinhole, a quarter of the required exposure time. When I made it my intention was to have a faster cameras to try to catch plants standing still and not to necessarily have a wider angle.

4x5 camera of 1 inch focal length.

 I made the camera especially for this exercise with same design as the five inch camera above. I no longer have it. It was displayed on a table in my office for years. The little collection was under some plants and was always getting wet when I overwatered them. I probably threw it away when I retired. Looks like a light leak in the upper left corner. 

8x10 inch of 2 inch focal length.

This one is exactly twice the size of the previous camera so the images should look pretty much the same.  I had made it a few years before to demonstrate some of these same objectives to the earlier classes. It's been the paper safe in my darkroom ever since.

8x10 inch camera of 10 inch focal length.

Exactly twice the size as the 4x5 five inch camera above, so a similar angle of view. I had originally made it to impress the kids when we did a group portrait in the workshop in 2001. (They weren't impressed).There was an extremely serious light leak and the negative looked essentially black. I photographed the negative on a light table and stretched the contrast to the limit to get the image back to something we could  compare with the others.

Curved back cameras

I don't use curved back cameras much, but since it's such a basic concept in pinhole photography, it was important to give the kids some experience with it. For the rest of the class, they could experiment with any of these cameras.

La Choy Noodle can 3 inches in diameter with a 4x5 negative.

To illustrate the barrel distortion of lines along a curved image plane, I had two of these. One was with the can sitting upright. With everybody trying to take pictures from the same place, I'm surprised there wasn't more bumping of cameras. 

And another one with the camera lying on it's side.

4 x 5 inch camera made from a quart paint can 5 inches in diameter set on its end

This is another camera which was in that display under the plants in my office which I no longer have. I didn't make this one. Probably through an interaction on Pinhole Visions email list, Jim Kosinski sent me one of his patented cameras, which you can still get at  Since it's a less extreme curve farther from the image plane, it should be less wide angle than the La Choy noodle cans.

4x5 inch camera flat front and semicircular curved film plane

Another camera that I don't have. This photo is of an 8x10 version. I made both the 4x5 and 8x10 versions specifically for this exercise. No one chose the 8x10. This configurations has an almost 180 degree angle of view. You can see other children setting up next to this one.

1.5 x 1.5 inch camera made from a 35mm film canister

This type of camera has become ubiquitous for solargraphy since Tarja Trygg started mailing them around the world.  Since it's almost the same proportions as the La Choy cans, the angle of view is almost identical. The pinhole on this one is a .15mm Gilder electron microscope aperture.

I had hoped to process all these and look at them right away with a negative image effect with a TV camera but it took longer to do and the ones who finished early went on to take more pictures. I made the positive scans that afternoon and put them up on the bulletin board for comparison the next morning. The kids were more interested in trying to take more pictures with the cameras and seemed a little bored when I tried to get a conversation going about it.

I thought of this because my latest camera project has been a 4x5 pinhole lab camera. I have to admit I did this post so I could play with my new computer while I wait to have some new negatives to work with.