Sunday, June 23, 2019

Manic Expression Cubed

I threatened to make a 24x24mm format camera with a rising front during the waning days of my fit of manic expression this spring. If the pinhole is also 24mm from the film (the diameter of a 35mm cassette) that makes it cubic, which is geometrically satisfying.

It’s the same template as my other 35mm Populists except with 12 millimeters cut out of the middle.

Several things motivated making this camera. It’s the same length/format ratio I’ve liked with the Evil Cube. I’ve been rather infatuated with the rising front in the last year and recall wishing it were an option when on the road with the 35mm Populists. I’ve gotten kind of a renewed fascination with the quality of 35mm pinhole. A square format also means you don't have to bother to turn the camera on the tripod. Working with the Oshkosh Public Museum's collection of early 20th century cameras,  I had noticed that some of the smallest vest-pocket folders, using 127 roll film, had rising fronts.

There’s a healthy dose of internet contrariness going on here as well. In the last month I’ve heard 35mm pinhole described as a joke in a reply to someone who was inquiring how to do it. Another assessment characterized it as a source of terror because you might be faced with too many pictures, particularly with a “36” exposure roll, which might require Sisyphean labors to process and edit. There was also a remark that such a wealth of frames could lead to the kind of indiscrimate variations digital photographers are so often accused of.

If this camera were to be proportional to the Evil Cube, the difference between the rising and axial pinhole would be under five millimeters. (The Evil Cube is over twice as big and has 10mm between axial and rising pinhole.) My cardboard, glue and Xacto knife construction methods are limited in accuracy. With them that close together, could I make a shutter precisely enough that one pinhole was covered when the other was opened?

When I started this rising pinhole business, it made my head hurt to think about a pinhole that actually moved up and down. Then I realized that this winter I had made a shutter that rotated 360 degrees! It shouldn’t be that hard to make an actual rising front.

I ended up giving it 10mm of rise from the axial position. Mr. Pinhole says the image area is 46mm in diameter at this distance so the vignetting shouldn’t be too bad at full rise.

The problem with that moving shutter is keeping it light-tight. There is no real light seal between the sliding shutter and the camera body. The sliding part of the shutter just presses up against the front of the camera. I overestimated how light-tight that would be. You could see the sun shining through the gap.

I added a few parts to reduce the vulnerable area to a minimum and to keep the slider under positive pressure against the front and that seems to have worked. The negatives show no evidence of light leaks. However, it had rained for a week and any sunny day was spent working in the garden. I did leave it out all day under a fairly bright cloudy sky.

If the pinhole is going up and down, you have to know where it is when you’re looking at it from the back. The actual sliding part extends the width of the camera and has beaded pins to indicate where the pinhole is.

Since there are 8 clicks for a 36mm wide frame and there is no whole number solution of 24/36 X 8, it will have to be 6 clicks per frame. Only thirty percent more pictures per roll of film. I’ll bet half the time I advanced the eight clicks per picture anyway out of habit.

I put the clicker on the supply side to see if that would be less touchy. It’s not.

It has a hand drilled .17mm pinhole.

Of course, the main use of a rising front is to keep your verticals parallel in a scene where otherwise you would be tilting the camera up.

A tilted camera is not so noticeable with something odd-shaped like a tree but it's nice to have the buildings near the ground not looking like they're leaning backward. This one is at the maximum rise. There was some vignetting near the top but with a lot of pictures, that helps control an overexposed sky.

Occasionally out on the road, I end up supporting the camera on a water glass or something and can't tilt it up, yet I want a higher point of view.  Here again, that maximum rise.

Sometimes the shift of that rising front can be handy even when you're not pointed up. I wanted to look straight down on my ugly feet without getting the desktop tripod legs in the shot.

On one of those rainy days, there was a spell of a light drizzle and the pinholer's dream of absolutely no wind, so I was tempted into the garden.

It doesn't take much breeze to make a fern flutter.

Peonies waiting to pop at the end of some long stalks. For those of you who are concerned that 35mm film isn't big enough for pinhole, this is a crop of about two-thirds of the frame.

The weigela blossoms didn't wait for the rain to stop.

And a particularly trembly subject as close as I could get to it.

All these were with Kodak Gold 200.

No comments:

Post a Comment