Last weekend I made the best of good winter light and time to spare for clambering up and down the rather slippery bank of the River Avon.
My cameras were almost ancillary to the restful experience that comes from the concentrated effort to find viewpoints and to set up for an exposure yet it is they and the images that ensue that give purpose to the solitary expedition. Here are a couple of memories from my day:
Making images with the shoebox pincam is a slow process. Four sheeets of paper or film have to be taped together then loaded together into the camera in the darkroom. Once exposed, the camera has to be returned to the darkroom for unloading and developing of each sheet. Getting to and from a previously scouted location takes time, the camera has to be set up and of course a pinhole exposure, especially on paper, is never done in a fraction of a second! As a result, it is likely that only one exposure can be made on any one day!
It’s almost two months since I idly picked up an empty shoebox and had the thought that it would be cool to convert it into a pinhole camera. That thought has turned into quite a project with teething problems to challenge me, lessons to be learned and only now can I say that I’m beginning to get a feel for what it can do.
The camera records a panoramic image covering about 145º horizontally, undistorted due to the constant radius curved image plane. The vertical perspective is similar to that of a ‘standard’ focal length 35mm camera, so is not the typical wide-angle view of a typical pinhole camera. So far I’ve used it to record river scenes, mainly because I like the effect that long exposures give to the movement of the water.
Here are four ‘useable’ exposures made so far. As each image comprises four sheets I’ve mounted them on board to ensure they are flat and accurately butted together. Unfortunately the assembled images are too large for my scanner so I have had to photograph them instead which doesn’t reproduce them as well, particularly for shadow details.
This first ‘successful’ image was considered so for the reason that I had overcome the safelight fogging problem that had dogged my first few exposures. I was being overoptimistic for the Direct Positive paper’s ability to record such a high contrast scene with one river bank in direct bright sunlight and the other in deep shadow!
For my second image I tried to cut down on exposure time by using film. I used Ilford FP4+, each sheet being subsequently contact printed onto Ilford MG Art 300 paper. While I achieved the aim of reducing the exposure time, the reduction was only slight due to accounting for reciprocity failure. Using film created its own challenges. First I had to tape together four sheets of film and load them into the camera in total darkness, then I had to determine a print exposure to be applied to each sheet when contact printing. To ensure accurate registration of the joined together contact prints, each negative had to be 100% accurately aligned to the paper. It was a tricky task and I spent rather longer in the darkroom than I had anticipated! Once again contrast was an issue but I’m pleased with the result and would give more thought to the camera position and lighting in future.
This is probably about one stop underexposed and I knew it at the time I made the exposure. It was a fifty minute exposure started about two hours before sunset and to give another stop in fading light would have added well over an hour for very little benefit. As it is there is very subtle shadow detail that doesn’t show up here and I absolutely love the wispy shapes formed by the water in the darker regions of the print. I’m not at all disappointed with this one. It’ll probably go into a frame, at least temporarily!
Finally I have this. I’d say I got the exposure just about right at 25 minutes or so, with good shadow detail in the actual print as well as here. I could have framed the shot better to take in less shadow area on the left and a better ‘flow’ downstream. The setting sun is directly in the picture and it’s path can be traced in the sorarisation that causes a ‘black sun’ effect from which the diffraction flare is seen. I quite like that and from time to time will set up a pinhole shot just to get that effect although that wasn’t my primary purpose with this one.
So there it is. I’m getting the hang of this ‘chance’ pinhole camera. It has a quite different perspective to any other pincam I have and I need to find the right subject matter to make the most of it. But it’s a keeper for sure!
My shoebox pincam wasn’t performing as expected. I couldn’t rest until I had it sorted.
The shoebox pincam has been more difficult to master than I had anticipated. In my previous blog post I recorded the design and construction, followed by a test exposure which I estimated to be a little over exposed. This was followed by an exposure that I expected to be good, taken on an outing to a tidal island and for which the pincam had been planned. That second exposure was uselessly overexposed and after some consideration I put the reason down to my error in metering the scene. Yet I’ve been unable to settle comfortably with that conclusion and so I set out this last weekend to have another go with the camera.
To recap: the camera has a constant radius curved image plane to be loaded with four (originally five) 5×4 sheets of direct positive paper taped together to make a 5×16 (originally 5×20) image. After the first two exposures I realised that the angle of view did not extend to a full 180º, but only to about 145º. By adjusting the support for the paper to accommodate only four sheets not only did I save a sheet but I avoided an ugly vignette at either end of the image.
For my testing on Saturday, I returned to the same riverside location that I had used for the original test. Conditions were much as they had been before and I made a similar exposure. When the image was developed I was surprised to find that each of the sheets making up the image were differently exposed/fogged. On the one hand I was puzzled by this while on the other I was relieved that the problem was clearly not one of my metering of the scene as each sheet had received the same exposure!
Assuming a light leak, I made some alterations to the light baffling on the lid of the shoebox, reloaded and returned again. This time all four of the sheets were clearly fogged, but not to the same degree. On one of the sheets there was even a clear difference in the pattern of fogging across it. It was enough to make me suspect either my safelight or (less likely) that the box of paper was bad.
Sunday was a dull, wet day but I have a pincam made from foamcore that is completely covered in gaffer tape rendering it effectively rainproof. I decided to make two exposures with it, one on paper loaded in the total darkness of a changing bag and the other on paper handled as it would have been for the shoebox pincam under the regular safelight in my darkroom. The results convinced me without any doubt that the paper was being fogged by proximity to and time under the safelight.
Towards the end of the afternoon the rain eased and the sky began to clear. By that time I had devised a support-cum-guide to speed up the process of lining up and taping together the individual sheets of paper. I had also relocated the safelight so that I would be working in its shadow and further away from it. With about two hours of daylight left and I decided to head out again for the riverbank. I had no expectation of there being enough light to make a full exposure but actually a couple of stops underexposure would better show up any fogging.
First test image
My darkroom is a temporary setup in a shower room. The walls are matte white and the work surface glossy white. For a safelight when taping together and loading these sheets I had used an old bicycle rear light which gives off a weak red glow, set on the work surface.
Had it not been for what I now recognise as fogging in the right-most sheet, I would have said this image is just overexposed a little with perhaps a light leak from somewhere. However with hindsight I realise that the rightmost sheet was exposed longest to the safelight and closest to it. The light edge to the left-most sheet should also have alerted me to fogging as the cause.
Second image (not originally intended as a test!)
Again, I should have realised this was fogged rather than overexposed. The vignetting at either end is clear and with direct positive paper any unexposed portion should be black.
When loading these sheets I had set up my regular deep red safelight, positioned on a hook about 1.2 metres above the work surface. Taping each of the five sheets together takes some time and I was doing so with the paper face down on the glossy white surface. Under the red glow it was difficult to see where the edges butted together to place the tape. I took all five sheets from the box at the same time so all were exposed to the safelight for the same length of time, probably three or four minutes.
Third test image
These sheets were loaded under the regular darkroom safelight as before but this time removed from the box one at a time, as needed, and kept face down on the work surface as much as possible. I had to reposition the tape on the third sheet and it probably had more direct exposure to the safelight as a result. The light edges all around each sheet suggest that fogging was occuring from light reflected off the work surface.
Fourth test image
This was loaded much the same as for the previous image. At this stage I was looking to the camera construction as the source of the fogging and had reworked some of the light-baffling and sealing on the camera. I was becoming more proficient at taping the sheets together which I think has led to more consistency in my handling of the paper and the subsequent degree of fogging.
Fogging test and resolution
This is the test pincam in the rain (left) and the two images which clearly show the difference between the paper being loaded entirely in darkness (centre) and having been handled under and exposed to for a couple of minutes, the darkroom safelight (right).
To resolve the fogging problem I moved the safelight to a different hook so that it would be further away from the work surface and in such a position that I would be working with the paper in my shadow.
I also made from black foamcore and mountboard, a support and guide that would both prevent surface reflections affecting the emulsion side of the paper and assist lining up and taping of the sheets. A second piece of mountboard was used to cover each sheet as the taping progressed, thus minimising and equalising the exposure each sheet received from the safelight.
Although this is almost completely black due to underexposure by two to three stops, the black is actually quite a joy to see. Had the paper been fogged while being loaded, that black would at best have been a lighter shade of grey. There is no suggestion of fogging around the edges of each sheet and consistency of exposure across the entire image is clear.
Conclusion … and a final thought
It has taken an entire box of Direct Positive Paper to reach but I reckon I can safely and comfortably conclude that the problem has been fogging due to overexposure to the safelight. I can also conclude that a resolution has been found.
One final thought: I’ve been using Harman Direct Positive Paper for almost four years. Why have I not noticed this before? The answer is that without realising it, there have been times that I have! Mostly I load single sheets directly from packaging to camera or film holder, often in a changing bag, and there has been no problem. However there have been times when paper has to be cut to size. Often, cutting a single sheet does not expose it sufficiently to be fogged but if I’ve been cutting a batch I’ll have had a growing pile of paper sitting in the light. Those are the cut sheets that didn’t produce the same contrasty ‘punch’ that I expect and love about this paper. Lesson learned!
All that remains will be for me to make a few good exposures in the weeks ahead. And they will have to be good as I have only one box of paper left. There’s no room for error either as I’ve discovered that it is currently unavailable from Harman and out of stock wherever I’ve looked!
It seems to be the way of things with me that ideas spring to mind in the oddest of places at the oddest of times. Sometimes they are gone forever before I have the opportunity to make a note, or they reappear in search of recognition at another odd time. Occasionally I get lucky and the idea stays with me long enough for consideration, perhaps acceptance and ultimately is put into practice.
So it was a couple of weeks ago on a crowded commuter train home at the end of a busy day, that I had the idea of creating a constant radius curved image plane pinhole camera out of a shoebox. A geometric puzzle to keep my mind awake amidst the noise of the train and the jostling of my fellow passengers.
The mental conundrum was too much to deal with but my mind wandered to thoughts of how I would record such an image. Perhaps a strip of art paper with SE1 emulsion brushed on? That would be cool – but it would be a negative image and how would I develop what would likely be a quite long strip of paper? Would I be able to make a positive contact print from it, perhaps on to another strip of SE1 coated paper?
Problems to be surmounted already and the idea still just at the stage of bouncing around inside my head. But how about direct positive paper? Would I be able to tape together enough of the 5″x4″ sheets I use in film holders to fit the image plane? It’s paper that I’m well accustomed to and as individual sheets it would be simple to develop. If nothing else it would be a good way of testing the camera design before moving on to ideas for other, more tricky media.
As I alighted the train for the short walk home my mind was buzzing. I had a plan. I had a project. I was going to create some pinhole art!
Sturdy shoeboxes are too good to throw away. They make useful storage boxes but better still, can be adapted to make pinhole cameras. It happens that I had two or three going spare. The box I chose has approximate internal dimensions of 33cm wide, 18cm deep and 13cm high.
Once made light-tight, the box could be fitted with a curved support on a radius of 16.5cm with a pinhole set centrally in the long side. Assuming full 180º coverage, the image plane would extend to 518cm wide by 12.5cm high and because it follows the radius of the curve, it would be free of both distortion and light fall-off along its entire length. The optimum pinhole diameter for a 165mm projection distance is roughly 0.6mm.
To ensure that the pincam would be light tight, the box and its lid were lined with thin black card. A strip of sticky-backed black felt was attached inside the lid to seal against the tops of the sides of the box. The card lining the sides of the box was extended about 1cm above the rim and folded inwards to form an additional light baffle.
The pinhole was made by pushing a dressmaking pin through a 3cm square of ArtEmboss mat black aluminium foil and positioned with black PVC electrical tape in the centre of the front panel of the box. More black PVC tape positioned over the pinhole aperture served as a shutter.
To form an image-plane support I cut a strip of card 518mm long by 130mm high, the length being calculated as the semi-circle of radius 165mm. A couple of spare pieces of foamcore served as a filler to support the back of the strip within the box.
Under safelight in the darkroom, I joined together five sheets of Harman Direct Positive paper with masking tape to make a strip 500mm long by 125mm high. This fitted neatly inside the box, supported by the image-plane card. With the top of the box secured by a couple of lengths of string I was almost ready to make my first test image.
I know from experience that although a viewpoint might be found, it is often unworkable because there is no way to support for the pincam in position! To get around this I like to make some provision for attaching my pincams to a tripod.
For the Shoebox pincam I took an offcut of plastic rectangular conduit cut to a couple of centimetres longer than the pincam is wide. I drilled a 7/32″ hole in the centre of the base and screwed the 1/4″ thread of a tripod quick-release plate into the hole. The metal thread of the mount effectively acted as a die to cut a thread in the softer plastic. To avoid stripping the new thread by over-tightening, I then fixed a 1/4″ threaded nut to the inside of the conduit, with the help of a big dollop (technical term!) of hot glue.
When the top of the conduit is slid back in place, the support is quite rigid and can be carefully mounted on a tripod. The pincam and support are held together by the string which also keeps the lid of the box in place. It may not be rock-solid but in pinhole terms it does the job perfectly! Being tripod mounted opens up a whole range of viewpoint options, levelling and height adjustment.
I took the Shoebox pincam to the banks of the River Almond on a bright Saturday morning. Shaded by the trees, my hand-held Sekonic L-308S meter and the iPhone Pinhole Assist app agreed on an EV(100) of 9.8, giving an exposure time of 53 minutes for direct positive paper rated at ISO 3. During exposure the light changed as the sky cleared and the sun lit the trees on the far bank of the river, so I reduced the exposure time given to 45 minutes.
Back in the darkroom I opened the shoebox to find that the semi-circulat image-plane support had slumped a bit towards one end of the box. That would need to be fixed.
With the masking tape holding the five sheets together removed carefully so as not to tear the back of the paper, I proceeded to develop each sheet individually, paying particular attention to time (3 minutes each) and temperature (19ºC) to ensure consistency from one to the next as all five would make up the single final image.
Exposure was good, perhaps a little over exposed for my taste. There was distinct vignetting at the end that had slumped while at the other end the print was lighter with lower contrast. Overall I was extremely happy with the result and after making an adjustment to the image-plane support, loaded up the pincam for a second test to be made next day.
To resolve the problem of the image-plane support moving, I strengthened it with four pieces of flower arranging wire taped to the back, and pushed two drawing pins through the centre into the foamcore filler at the back. My expectation for the second test would be to find out whather the vignetting noticed in the first was due to movement of the paper or actual cut-off of the field of view.
For the second test I joined a couple of friends for a walk across the tidal causeway to Cramond Island, with an idea to make a pinhole exposure of the war-time gun emplacements and concrete huts. It was another bright day, this time with steady soft light from a light grey backlit sky.
Again, my Sekonic and iPhone agreed on the light, metering EV(100) of 11.8. To allow for yesterday’s perception of slight over-exposure I rated the paper at ISO 4 (1/3 Stop faster) and gave the metered 12 minute exposure.
Back in the darkroom again, the fix made to the image-plane support had done its job and I processed the paper as before. Two things were immediately obvious: Clear vignetting at either end of the image suggesting an effective field of view amounting to about 145º rather than the full 180º semi-circle I had hoped for; and rather disappointingly an inexplicably overexposed image!
The over exposure of the second image was quite unexpected. I rechecked all of my measurements and calculations and finding them all correct I proceeded to remove the pinhole to accurately check its diameter.
I mounted the pinhole alongside a steel milimeter rule on the bed of my scanner and scanned at maximum resolution. Viewed at full size on screen I was able to measure the pinhole and by reference to the magnification of the known milimeter rule, calculate the diameter as 0.612mm, exactly as intended and giving an aperture of f/269.
With all the variables checked and found correct, I was left with only one conclusion to explain the over exposure -human error – mine! On the first test the sky had been obscured by the trees while the second was under an open sky. I can only conclude that on the second test I have pointed my meters at the wrong part of the scene and failed to account for the brighter conditions.
More care needed next time methinks! And I do intend that there will be a next time as soon as possible. I want something worthy of a frame on my wall.
There is a follow up to this in my next blog post. In it I come to the correct conclusion and find a resolution!
Low tech camera fun on a photowalk with three very different cameras.
With our usual meeting place packed to the rafters during the Edinburgh Festival, the Edinburgh LoFi Photography group escape the city every August for a photowalk outing instead. This year we headed west along the River Forth to Blackness and a walk along the shoreline to Abercorn.
I took three cameras: my Vest Pocket Kodak model B loaded with ReraPan 100 127 film, my Harman TiTAN 4×5 pinhole camera loaded with Direct Positive paper and my kit 35mm TLR (plastic Recesky/Graffenflex clone) loaded with Kentmere 100 film.
The company was genial, the weather fine enough and our assorted cameras varied and quirky. I had a reason for each of the cameras I had taken. Here’s how I got on, camera by camera. The images are all straight unretouched scans of the negatives or paper.
Vest Pocket Kodak model B
A junk-shop find gift for Father’s Day from my younger daughter, this camera was in great condition when it arrived except for a small light leak in the bellows. I blogged about repairing the leak here a couple of months ago and this was the camera’s first outing with film to check that all was now well.
There are four aperture settings giving f/11, f/16, f/22 and f/32. I reckon the shutter speed is about 1/30th sec on the ‘I’ (for Instantaneous) setting and there is also a ‘T’ setting which allows the shutter to be opened with one stroke of the lever and then closed with a second stroke. The bellows open to what is effectively a fixed focus setting for infinity. All eight frames were exposed at f/16. Frames three and four, taken inside Abercorn church were exposed for approximately eight seconds each with the camera tripod mounted.
I am really pleased with these. The light leak is definitely fixed and this ninety year old camera functions as it would have done in it’s hey-day. I could have made better use of the aperture settings for frames 5, 6 and 8 as these are a tad overexposed.
The ReraPan 100 film was developed in Ilfosol 3 diluted 1+9 for six minutes at approximately 18ºC.
Harman TiTAN 4×5 Pinhole
I’ve had this several years now and with Direct Positive paper it is one of my favourite image making combos. Abercorn Churchyard was one of the first places I took it to try out. The results of that early outing were put down to being a learning experience, both for angle of view and exposure. This was an opportunity to prove that lessons have been learned! I was not disappointed.
Direct Positive paper is high contrast with a short range that is uncompromising in exposure and development. But get it right and it absolutely rocks with deliciously deep subt’ly detailed blacks and a luscious texture that really needs to be appreciated as an original print rather than as a scanned digital image.
The prints were developed in fresh Ilford Multigrade diluted 1+9 for three minutes at something like 16-17ºC.
Plastic kit 35mm TLR
A birthday gift from my older daughter, this twin lens reflex camera, a clone of the Recesky kit camera which itself is a clone of the original (?) Graffenflex camera, comes as a box of parts with a detailed instruction manual for assembly. I had great fun assembling it earlier this year but after putting a couple of films through it, consigned it to a shelf as an ornament having described it as being about as light tight as chicken wire!
However, I recently took it down from the shelf, disassembled parts of it and attempted to seal up the light leaks with electrical PVC tape and sticky-backed black felt, just as I would do on a homemade pinhole camera. This outing was a chance to find out if I had suceeded! The aperture is fixed at about f/11 and I reckon the shutter speed is about 1/60th sec. The plastic lens can be focussed after a fashion and comes complete with vignetting and a mix of sharp and unsharp ‘zones’. Winding on the film is hit or miss so framing overlap is not uncommon. All in all a truly fun camera with no promise of success! I managed 27 barely recognisable exposures from a length of bulk-loaded Kentmere 100 …
There’s still some light leaking in but I had so much fun taking these snaps that I’m going to see if I can sort it. I just have to use this camera again!
The Kentmere 100 film was developed alongside the the ReraPan film in Ilfosol 3 diluted 1+9 for six minutes at approximately 18ºC.
My eyes were closed as I savoured the moment with the object of my desires, gently feeling my way around in the darkness, the rythmic sound of the darkroom clock in the background as the sweet aroma of fixer filled my nostrils, knowing that at the tip of my fingers things were developing …
My preferred method of developing sheet film is six at a time in a Paterson tank with a MOD54 adapter. However if I have only one or two sheets that I want to assess, I resort to tray developing.
Tray developing is done in the darkroom, in the dark: no comforting warm glow from a red safelight, knowing where everything is laid out, relying on touch to gently work from tray to tray, listening keenly to the tick of the darkroom clock, shutting out all distractions to count down the seconds. It’s an intense spellbound time alone with just a piece of film for company. Strangely I often find myself closing my eyes as if to shut out the dark in the darkness.
I’ve been experimenting with a zoom pinhole technique in an attempt to create a ‘look’ for a wee project I’m thinking about. It’s quite a simple idea: To use the ratchet focussing mechanism of my Intrepid field camera to adjust the pinhole projection distance during a long exposure with a lensboard mounted pinhole.
So today with good, bright conditions forecast I exposed two sheets of Harman Direct Positive paper and then two sheets of Ilford FP4+. With a five stop ISO difference between the two media it would be interesting to see the different results each would produce.
Direct Positive Paper
For the Direct Positive paper, exposures given were about three minutes – I feel four would have been better but I got what I wanted from the prints. The zoom range was from 190mm to 100mm with a 0.5mm pinhole. It felt difficult to match the zoom action to the time available and the second exposure was much the better for the experience of the first!
The first ran out of zoom and was zoomed a second time before the exposure was completed. It was also a poor choice of subject with a big slab of shadow on the right (left in the print!) that’s pretty much underexposed. The second is a bit underexposed but is close to the effect I think I’m looking for and my favourite from the day.
The FP4+ exposures were over the same zoom range but with exposure times much reduced to around four seconds. I had expected that zooming over a shorter exposure time would be easier but actually found it rather rushed and very difficult to control.
The first is a bit jerky as I struggled to cover the zoom range within the exposure time. I was ready for it for the second exposure and though I like the result, the day was too bright to fully achieve the effect I wanted. The exposures were just too short – an unusual comment for a pinhole!
It’s been an enjoyable day: out and about with a camera, trying something different, taking food for thought from the results and of course, that sensual time in the darkroom!
I took a Trip to Falkirk for an Intrepid photo-outing. But not all went to plan …
The idea was to take The Intrepid and a half a dozen sheets of Harman Direct Positive paper for a walk around The Falkirk Wheel, a unique boat lift between the Union Canal and the Forth and Clyde Canal in central Scotland, and then on for a visit to the nearby site of the Antonine Wall and Rough Castle Roman Fort. For a few snapshots along the way I took my Olympus Trip loaded with Kentmere 100 film.
Two cameras, one to be set up on a tripod after careful consideration of the viewpoint then focused, loaded, light measured for calculation of shutter speed and aperture before the exposure could be made. The other in a pocket to be taken out, pointed at the subject and the shutter pressed to take the shot without delay.
Nobody takes a blind bit of notice to the Olympus Trip whereas The Intrepid attracts all manner of attention. People stop to look. They ask questions. They tell of their forebears using cameras like these. Their children have to see what’s going on below the dark cloth and their dogs are attracted to the legs of the tripod!
All of that attention when trying to concentrate on the process of taking a photograph with The Intrepid can lead to confusion for the old codger that I am! I made a complete mess of exposure meter readings and camera settings. Of my six sheets of paper only one came out as I had intended, one of two barges passing each other on the Union Canal above the Wheel.
The remaining five were all either very under- or very over- exposed. However, one of these, of the entrance to Rough Castle Tunnel, although about three stops overexposed has been growing on me so I count it amongst the ‘keepers’.
So there it is. Memories of a day out, exposures made, lessons learned and the sense of satisfaction from crafting the images back in the darkroom.
Pinhole images – why be satisfied with one when you can get cross-eyed over a pair?
A few weeks ago while spending a dull, wet weekend clearing up my photo stuff I came across a box of odd bits of Harman Direct Positive paper left over from a workshop I ran quite some time ago. I was pretty sure the paper hadn’t been handled in entirely light-safe conditions and would be fogged but rather than waste it I loaded it into a variety of cans and boxes all of which had been converted for pinhole use. When the weather improved I could have a play and see what transpired from the paper!
One of the converted boxes had been a Father’s Day gift containing whisky flavoured truffles. Once the contents had been dealt with the true purpose of the box was realised as a two-shot pinhole camera, allowing for two separate exposures to be made before having to return to the darkroom or fumble in the dark bag for a change of paper or film. Two chambers and a frame to hold media in place was formed from foamcore, the interior was given a spray of flat black paint, two holes were cut in the lid and pinholes taped over the holes.
Coincidentally, I had been reading of my friend Oonagh’s endeavours in 3D imaging with an antique Wray Stereo Graphic 35mm camera. It occurred to me that my two-pinhole Whisky Truffle Pincam could be adapted to make a stereo pinhole camera.
To make images suitable for viewing as a stereo pair, they need to be taken of the same view but from viewpoints slightly apart. That is taken care of by the two adjacent pinhole apertures. The exposure given to each needs to be as near as possible the same – that will depend on how well I can make two equal pinholes!
Ideally to view the 3D effect requires a stereoscope which optically overlaps the images so that the viewer sees a virtual third 3D image. However at the cost of a little discomfort, By squinting at the two images they can be made to overlap in the same way. This would do me for now!
The original pinhole apertures were just as they had been made. In true pinhole fashion there had been no attempt to match them. My first test stereo image confirmed that my Direct Positive paper was indeed fogged but as my purpose was to compare the differences in aperture, the expected fogging was not important. More significantly, the first pair of images show that the Right pinhole (the one on the left!) was wider than that on the Left (the one on the right!). This would need to be corrected if I was to make a successful stereo image pair.
Having made my initial assessment, I decided to balance the apertures by attempting to enlarge the Left pinhole just a smidge. Of course having made the intended adjustment I felt the smidge was perhaps a tad too much and so adjusted the Right pinhole by the said tad, more or less. The result was not pleasant with both images now overexposed, too soft and neither a match for the other.
There was only one thing for it: re-make the pinholes from scratch, aiming for a matched pair. The optimum aperture diameter for a pincam with a projection distance (i.e. focal length) of 36mm is around 0.25mm so that’s what I was aiming for although size was less important than equivalence.
By laying the pinholes alongside a millimetre rule on the bed of my scanner and scanning them at its highest resolution I was able to make reasonably accurate measurements of their respective diameters and an assessment of their regularity. The Left pinhole measures 0.33mm and is quite a clean, round hole while the Right pinhole is 0.30mm, more elliptical and a bit rough on one side. With a projection distance of 36mm the relative apertures were f/110 and f/128.
The difference between f/110 and f/128 would have been neither here nor there in a single exposure ‘regular’ pincam but I was surprised by the effect on the final pair of stereo images of such an apparently small difference in aperture. Ideally for a stereo pair, the exposure given to each image should be precisely the same. That said I’m satisfied with the closeness achieved.
(I had attempted in the final image to add an extra layer of depth in the form of a ghostly selfie in the gap between the foreground stump and the distant tree. Unfortunately I missed my positioning but look carefully and I can be seen directly in front of the tree!)
The Democratic Camera Club which meets monthly at Stills, Edinburgh and of which I am a member has organised a Winter Exhibition. I am thrilled to have had four of my pinhole images accepted and am honoured that they will be displayed alongside the exhibits of fellow club members and artists whose work I admire and take inspiration from.
My images were made with my Harman TiTAN pinhole camera on Direct Positive Paper and so each exhibit is an original, unique image. They were made in the area of Talla Water reservoir in the Scottish Borders.
I sought to find a balance between the rugged beauty of the natural landscape and those elements of that landscape which man has used to his own end: reservoir, walls and bridge. I find serenity in contemplating the purposeful recreation of these elements blending with the land from which they were formed. A new ‘natural’ landscape is created wherein the man-made draws the eye and the mind to the beauty of the natural shape and form of hill and valley.
The originals have so much more depth than these scans can show. Come along to the exhibition, see it for yourself and enjoy all of the excellent photography on show.