World Pinhole Day was the last Sunday in April and its approach made me notice that I knew nothing about pinhole photography. Plenty of people I respect on the analogue side of the internet swear by it. I had never put a sheet of film through a pinhole. It seemed time to fix that.
This is the writeup of my first proper go. I made a pinhole lens board for the Intrepid 4x5 out of aluminium and brass and took it out to Worcester Lodge near Didmarton with Ashley Robson modelling, where I shot a handful of sheets of Foma 400. The results were not what I had been led to expect and the lessons were specific, and I have come away with a clear sense of what I would do differently next time. Whether I will get a next time is the genuine question I am still working out.
Making the lens board
The Intrepid takes a square lens board with a circular hole in the middle for the lens. For a normal lens that hole is precisely sized to the diameter of the lens flange. For a pinhole, the hole needs to be small enough that the brass plate behind it can be drilled with something approaching a 0.4mm aperture, which is genuinely small.
I had a half-finished aluminium lens board on the bench from another project. I cut a roughly 20mm circular piece of half-millimetre brass sheet and glued it to the back of the aluminium board with contact adhesive. The brass is thin enough and soft enough that I could in theory drill a very small hole through it. The aluminium gives the rigidity.
The focal length I wanted was 90mm, which is on the wide-angle side of normal for 4x5. The MrPinhole website (mrpinhole.com) is the proper resource for working out the optimal pinhole diameter for a given focal length, and it told me that a 90mm focal length on 4x5 wants a 0.4mm hole, which gives an effective aperture of f/225. F/225 is a number that exists nowhere on any light meter I have ever owned. I will come back to that.
The drilling did not go to plan. I had bought a set of micro drills that should have handled 0.4mm with no trouble, but the brass was just thick enough and the drills just soft enough that I lost two of them inside the brass without making meaningful progress. I lost patience and finished the job with a small hammer and a sewing needle. The resulting hole is bigger than 0.4mm. I do not know precisely how much bigger. Not catastrophically so. Possibly enough to be a factor in what came back on the negatives.
This is the kind of detail you would think a pinhole purist would tut at. They would be right.
The shutter
A 4x5 lens board does not have a shutter, because lenses for 4x5 have shutters built into the lens itself. A pinhole lens board does not have a shutter at all, which is a problem because at f/225 you are still talking about exposures of around one second in bright sunlight. You need a way to start and stop the exposure that is more controllable than just covering the hole with your finger.
The neatest solution I could think of was magnetic. I stuck two small disc magnets to the front of the lens board on either side of the pinhole, then cut a small steel cover from an unused steel lens board I had on the bench. A piece of black felt on the inside of the steel cover stops any sneaky reflections through the gap. The cover snaps onto the magnets and stays put. Lift it off to start the exposure and snap it back on to end. Simple and robust, with no moving parts to fail.
This bit of the build worked genuinely well. The magnetic cover is the part of this experiment I am most pleased with.
Working out exposures at f/225
Light meters generally go up to about f/45 or f/64 at the slow end. F/225 is roughly six stops smaller than f/32, which is the practical upper limit on most meters. So the way you work out a pinhole exposure is to meter at f/32 or f/64 (whichever your meter will give you) and apply the appropriate stop conversion to get the equivalent at your actual aperture.
MrPinhole has a conversion table for exactly this purpose. I used it. For a 90mm pinhole at f/225 I was looking at about a one-second exposure in the bright sunlight we had on the day, with Foma 400 metered at ISO 64 to keep the maths simple. The ISO 64 setting is a bit lower than the box speed of 400, which on Foma 400 is a sensible choice because Foma 400 famously underexposes if you take the box speed at face value. EI 200 or thereabouts is the more honest rating.
The shoot at Worcester Lodge
I picked up Ashley Robson (who has modelled for me on the channel before and is a genuinely patient sort) and drove out to Worcester Lodge near Didmarton, on the edge of the Badminton Estate. The Lodge is a Palladian gatehouse on the Tetbury Road, with a wide open landscape behind it and the kind of crisp architectural lines that I thought might suit the dreamy softness of pinhole.
Ash arrived dressed properly for it, in bright contrasting clothes and sunglasses, with his usual funky hair on top. We had agreed in the run-up that pinhole exposures are long enough that the subject has to hold still for the count, so his job for the morning was to be a statue. He delivered.
The first frame was Ash leaning against the Lodge with the building filling the right side of the frame and open landscape behind. One second at f/225. I lifted the magnetic cover for the count of one Mississippi and snapped it back on. The whole thing felt like nothing was happening. There is no shutter sound and no mirror slap. No audible indication that an exposure is taking place at all. You are just standing there counting. I genuinely was not sure I had taken a photograph.
The second frame was the same setup with a slightly longer count, because I had no confidence in the first. After that we moved on to a tree-lined road for frames three and four, with Ash standing in for a more conventional portrait. The two frames I was most interested in came last. Ash looking down into the camera from above with sunglasses on, the lens pointed up at him at close range against the canopy of a tree. I knew this was the kind of pinhole frame I had seen in other people’s work and wanted to try.
I shot one of those handheld off the tripod, which is a slightly reckless thing to do on a one-and-a-half second exposure on 4x5, because I wanted to get the camera lower than the tripod would go.
What the negatives showed
Some of the frames came back good. The Ash-looking-down frames are exactly the ones I had been hoping for. Soft and dreamy, with a strange sense of depth that comes from the pinhole rendering rather than from any conventional focal-length compression. He looks like he has been photographed by someone in 1895.
Some of the frames came back too blurry to use. The architectural frames at Worcester Lodge are softer than I had hoped. The portraits at middle distance on the tree-lined road are softer than I had hoped. Pinhole is supposed to be soft (that is the point) but the kind of soft I was getting was not the kind of soft I wanted.
A few possible explanations. My pinhole is bigger than 0.4mm because the hammer-and-needle finish gave me a hole I cannot precisely measure. The lens board to film plane distance might not be exactly 90mm because the brass sits a millimetre or two behind the front face of the aluminium board, which I had not properly accounted for. And from what I have since read, every pinhole has an optimum subject distance at which everything is at its sharpest, with subjects significantly nearer or further than that distance going progressively softer. I had not been thinking about that on the day.
The genuinely interesting observation is that the close-up frames of Ash (the looking-down-the-lens ones) are sharper on Ash than the middle-distance frames are on Ash. Sharper is the wrong word for pinhole but the relative effect is real. The closer I got, the better-defined the subject became. The opposite of what I had been led to expect.
What I think I have learned
A few specific lessons from the experiment, none of which I had thought about in advance.
My pinhole is too big. The hammer-and-needle finish has cost me sharpness I cannot get back without making a new lens board. The next attempt will be done with better drills and a slower hand.
The optimum focus distance question is also more interesting than I had realised. From what I understand now, a smaller pinhole gives sharper images overall but a longer exposure. The position of “best focus” (such as that concept means anything for a pinhole) varies with hole size and focal length in a way I do not fully understand yet. If anyone reading this knows whether a wider pinhole gives sharper close subjects at the expense of distant ones, I would genuinely like to hear it. The question is in the comments under the video and a couple of people have offered partial answers but I am not yet confident I understand the optics.
Finally, pinhole rewards intentional composition more than I had guessed. The frames I am happiest with are the ones where I had a specific look in mind before I lifted the cover, not the ones where I was trying to make a conventional portrait that happened to be on pinhole. The medium suits something more deliberate.
Where I am on pinhole
Honestly, I do not yet know. The Ash-looking-down frames are good enough that I can see why people are drawn to pinhole. The architectural frames are weak enough that I can also see why I have not been until now. The medium gives you something specific in exchange for a degree of control that I am not used to giving up. Whether that exchange is worth it for me as a photographer is the question I am still working out.
What I do know is that the magnetic lens board works and the MrPinhole conversion tables are accurate. Ash is a genuinely patient model. The next pinhole outing will be properly planned, with a better-drilled hole and a clearer idea of what the medium can and cannot do at different subject distances.
If you have an Intrepid (or any large format camera) and have been curious about pinhole, the lens board build is genuinely easy. A piece of half-millimetre brass, a sewing needle, two disc magnets and the MrPinhole calculator will get you the same setup I have. Allow an hour. Allow more if you decide to drill the hole properly rather than my hammer-and-needle approach.
Big thanks to Ash for standing still for a minute at a time in the cold sunshine while I worked out whether I had even taken a photograph. You can see his work at ashleyrobson.com.
The next video on the channel was the Bronica three-lens shoot in Tetbury, which is a genuinely different sort of project. After that I will come back to pinhole when I have understood the optics a bit better.