Tuesday 29 April 2014

Talking about pinhole photography with security guards in the park

Ilford 8.2cm Special Lantern Plate, 10 minute exposure
Two days ago, 27th April, was 'Worldwide Pinhole Photography Day'. In the past this particular day in the photographer's calendar has been one that I haven't observed, and it's been an odd lacuna that, in all the formats and techniques I've used, I've not made a pinhole camera before. This seemed a good occasion to fill that gap. After my recent work with vintage glass plates, I naturally wanted to use them for the pinhole day. In considering what form the cameras would take, I decided to make them square, and to use some lantern plates I had which I hadn't previously shot. Prior to, and then concurrent with transparency film, lantern plates were used to make glass slides for projection and typically would be made by contact or with an enlarger. Before the pinhole day, I tested two types of 8.2cm square lantern plates for exposure, Ilford Special Lantern plates and Kodak L5 Warm Tone Lantern plates. I shot these with the MPP Micro-Technical camera in adaptors made as detailed in a previous post, using a starting exposure index of 5, thinking that the lantern plates might have an emulsion sensitivity similar to photographic paper, and took three successive exposures by progressively withdrawing the darkslide, effectively giving exposures (from right to left) at 5, 2.5, 1.2 to seen how much sensitivity the plates may have lost with age. The Ilford plate box had a leaflet inside dated to November 1965.

Ilford Special Lantern plate test, scan from contact print on Kentmere VC Select paper
The Ilford plates provided better results, with less fog and less silvering than the Kodak L5 plates.  Ilford's were the fastest lantern plates they manufactured ('Gaslight' and 'Contact' plates were also available), an important factor for the choice of these plates with pinhole cameras, and the Special Lantern plates were also made in three different grades of contrast: 'Soft' 'Normal' and 'Contrasty'; when shooting these as negatives, the 'Soft' contrast grade is still high, which reinforces the suggestion that the lantern plate emulsions were similar to that of photographic paper, which is usually high in contrast when used as a paper negative. The plates for the test were stand developed in R09 One Shot at a dilution of 1:100 for one hour.

I made pinhole cameras in two different sizes, to fit the 8.2cm plates tested, and 2-inch square plates, of the same type. I made the cameras from stiff card and constructed two cameras of each size; when working with glass plates it makes sense to work in pairs, as this is how the plates are packed. The pinholes were made from small squares of metal from aluminium cans, with a pin, not pushed all the way down the shaft, but merely rotating the tip to create as smooth and round a hole as possible. I measured the pinholes by scanning these at high resolution, which came out at either 0.3 or 0.2mm diameter. This measurement could then be used to calculate the f-stop of the pinholes (the f-stop number being focal length divided by aperture diameter). For both large and small cameras I made them with a focal length similar to the width of the plates, which is effectively wide angle, the focal length being less than the diagonal measurement of the image format. On the small cameras, a pinhole diameter of 0.2mm equated to f255; 0.3mm was f170. On the larger cameras these diameters gave f-stops of f400 and f274 respectively. As I wasn't able to measure the pinholes more accurately (to 1/100th of a millimetre for example), these figures were approximations, but having tested the sensitivity of the plates, I had enough information to roughly calculate the exposure times needed. Ideally I would have tested the cameras themselves before the day to see any potential shortcomings, of which there were a few, but I was still making them on the morning of the 27th.

Pinhole Camera for 2-inch plates
To shoot the cameras, I decided not to take a tripod, which meant having to find spots where the cameras could be placed for the long exposures needed, and, intending to shoot more than just four plates, I also took a dark bag, boxes of unexposed plates, and empty boxes to place the plates once shot. I started at Marsh Lane Fields in Leyton, where there was a convenient picnic table, on which I could set up a couple of the cameras for exposures of 15 and 6 minutes (and sit and read the paper while the shutters were open).

Ilford 8.2cm Special Lantern Plate, 15 minute exposure
I then walked on towards the Queen Elizabeth Olympic Park where I shot a couple more large plates on a verge sandwiched between Ruckholt Road, a slip road for the A12, the A12 flyover itself and the River Lea. This used to be one of those undesignated left-over spaces (which I have photographed before), but has recently been landscaped to provide a path along the bank into the Olympic Park. There was a sluice gate there which provided a platform to place the pinhole cameras for some more exposures. I also changed plates with the dark bag while there.

Ilford 8.2cm Special Lantern Plate, 10 minute exposure
Entering the Olympic Park, and following the Lea, I found a bench on the other side to sit and position one of the cameras to take the photograph which appears at the top of this post. While I was sitting there reading the paper, a golf buggy drew up with two security guards. I'd have liked to have recorded the encounter which followed, but I shall just describe it as well as I can recall. They said that I had been picked up on the security cameras; I can't remember exactly whether they said I'd been seen taking pictures near the children's playground, or if they just asked had I been taking pictures there. I don't know whether they were simply mistaken, or if this was an invention used to justify questioning me, but the insinuation was made. I hadn't been near the playground, and didn't know where it was at the time (I looked this up when I returned home); I may have been relatively near to it when crossing from one side of the Lea, by the Velopark, to the other, but I certainly wasn't taking any photographs at the time. It didn't seem worth explaining that the pinhole exposures of ten minutes or more would be of no use to what they seemed to be implying. They appeared to accept my denial of taking photos at the playground, but had more questions. I had been seen writing things down, which I had, so I showed them my notebook on which I'd written entries such as "3.54 No. 1 Large - River Lea/10 minutes". They then wanted to see the cameras. I only had the one out that I was taking the picture with, so I curtailed the exposure, which was going to be longer, and they also asked if I was leaving these around the park. I explained I only had four cameras and was keeping them with me. The security guards then asked what I was taking the pictures for, at which point I couldn't help entering a philosohical frame of mind (for some reason I declined to inform them that it was 'Worldwide Pinhole Photography Day'). I resisted the temptation to say "to see what things look like when they're photographed," circular but honest reasoning. I was asked if the photographs were going to be shared anywhere, and I said 'probably' on Flickr. Then they said I'd also been seen taking photographs on a phone or digital camera. It was only later that I realised what had been seen on the security cameras and not understood was my use of a handheld lightmeter; however I did have my Kiev 30-M in my pocket, and although I hadn't used it inside the park, I did tell them I had a film camera with me. They asked if they could see the photographs. I had to disappoint them by explaining they couldn't see the photographs as these would need to be developed. At this point I could sense that conversation wasn't providing any more avenues for the security guards to go down, and after some small talk about the transformation of the area, during which I kept my views of the Olympics to myself, one of the guards said "I don't have any problems with you taking photographs in the park". They had been polite throughout, and, to be generous, I can see the need for suspicious behaviour or behaviour that is not understood to be investigated. However, the statement or question about the children's playground was insidious and unnecessary. Having satisfied the security guards' questioning, I left the Olympic Park by the nearest exit.

Ilford 8.2cm Special Lantern Plate, 20 minute exposure
I took a few more shots returning along the canal, such as the image above, then finally some shots at home as the light was failing, with exposures well over an hour to compensate.

Ilford 2-inch Special Lantern Plate, 1 hour 20 minute exposure
I stand developed the 8.2cm plates for an hour, using a higher dilution of R09 One Shot, 1:150, to reduce contrast a little more than the earlier tests. Meanwhile, the smaller plates were tray developed by inspection in R09 One Shot 1:120: one of the benefits of using the lantern plates is that they are orthochromatic so can be handled under a red safelight. All but one of the plates used were Special Lantern plates, but I did also shoot a 2-inch Contact Lantern plate, which proved both slower and higher in contrast than the Special Lantern plates: this was tray developed for a considerably longer time than the other plates, but there wasn't sufficient exposure to provide any shadow detail. All the negatives had come out, but there had been some problems, particularly with the small cameras, some of the plates not sitting properly in the slots I'd made to hold them inside the cameras, and some slight light leaks, problems which I might have been able to elimate had I tested the cameras beforehand, but I wasn't disappointed with my first pinhole photographs.

See the whole set of pinhole photographs here.
Worldwide Pinhole Photography Day website.



Thursday 17 April 2014

Recent three colour process images

Three colour process, separation negatives shot on Ilford Delta 100 with Zodel Baldalux,
colour RGB image composited in Photoshop CS2
In my post last year, 'An Experiment with Three Colour Photography', I described the technique of using three black and white photographs to produce a colour image. For that experiment I used large format film, which meant the taking of each separate shot was inherently slowed down by the process of shooting sheet film. I also had problems when scanning the negatives to create the colour image, as I had to scan each in two halves, leaving problems with both alignment and balancing the colours in the three RGB channels. I subsequently took the tri-colour filter set with me to St Petersburg last September, but only used them for one medium format shot. By necessity this was hand held, and not much quicker than shooting large format, with the problem of holding the camera and the gelatin filters in front of the lens and then pressing the shutter button with two hands (while a stiff breeze threatened to blow the filters into the Neva river). Despite the results needing a good deal of cropping as each shot was not very well aligned through being hand-held, the very distinctive qualities of the three colour technique made me wish I had used it for a few more shots on this journey.

Hand held three colour process, separation negatives shot on HP5 Plus
with Zodel Baldalux, colour RGB image composited in Photoshop CS2
For the above image, a tripod would have ensured a better alignment of each colour. Using roll film rather than large format means that each shot can be taken with quicker succession, although I was still using a manual camera which required cocking the shutter and advancing the film using the red window between each shot. Anything moving in front of the camera shows the time taken between each frame, such as the figures and waves in the shot above, and the clouds. Recent good weather has provided the opportunity to take some more three-colour images. I had hoped for some cloud-free days, as these are the one aspect of the landscape shots which highlight the brief time discrepancy between each shot, but entirely cloudless days are rare. The image at the top of this post was the best of the recent shots; the photograph immediately below shows some problems with shooting into the sun with the filters held in front of the lens causing reflections. The tri-colour filters I have been using are unmounted squares of gelatin, which have the tendancy to pick up fingerprints very easily, and are difficult to clean and this particularly shows up when the sun hits the filter surfaces, and a slight soft-focus effect results.

Three colour process, separation negatives shot on Ilford Delta 100
with Zodel Baldalux, colour RGB image composited in Photoshop CS2
Three colour process, separation negatives shot on Ilford Delta 100
with Agfa Record I, colour RGB image composited in Photoshop CS2
Three colour process, separation negatives shot on Ilford Delta 100
with Agfa Record I, colour RGB image composited in Photoshop CS2
As the 6x9 format gives eight images on a roll of 120 film, this meant that I could shoot two sets of three colour separations, with two frames left on the film. On some of the films I used these frames to shoot second versions of some colours, but I also tried a two colour separation, shooting just through the red and green filters. When making the RGB composite I used the green filtered negative in both Green and Blue channels, essentially giving a red/cyan colour image. This effect was intended to mimic the two colour bipack systems used in the early part of the twentieth century for colour motion pictures (see the Wikipedia article on Bipack Colour).

Two colour process, separation negatives shot on Ilford Delta 100
with Zodel Baldalux, colour RGB image composited in Photoshop CS2

Wednesday 9 April 2014

Glass plate adaptors

Adaptors to use 10.8x6cm glass plates in 4x5 inch plateholders
In my last post, 'Some odd-sized glass plates', I wrote about making adaptors to shoot the 10.8x6cm HP3 glass plates in 4x5 inch plateholders; a comment on the post about the passing reference to making the adaptors has provoked me to illustrate them.

Adaptor diagram (to scale at 96 dpi)
I used mountcard of the sort that should be found in any good arts and crafts suppliers. The mountcard itself is roughly 1.5mm thick. The adaptors are made from two pieces of card glued together with PVA glue. The lower piece of card, shown in green outlines above, is the dimensions of a 4x5 glass plate, with an aperture cut in the centre to fit the plates in. The upper piece of card, in red, has a smaller aperture, 2mm narrower on each side, which provides a lip to hold the plate in place. In terms of the thickness of the adaptor as a whole, there's enough clearance with the plateholder's darkslide that the additional height does not interfere with sliding the darkslide in and out. The emulsion surface of the glass plate should be level to the plane of focus, being held in place by the curved spring from behind and flush with the surface of the lower piece of card, which itself should be held exactly as a 4x5 plate would be. Importantly, the upper piece is reduced in length so that either end of the adaptor fits under each end of the plateholder. I've found that plateholders do vary a small amount in their tolerances: the above diagram fits Type II plate holders by Folmer Graflex Corp. The 5mm difference between the upper and lower pieces at the right end of the diagram above fits under the top end of the plateholder, the 3mm end fits under the lower (folding) end of the plateholder, as shown in the image below (rotated 180ยบ, so the folding end of the holder is on the right in the picture).

Adaptor in 4x5 Folmer Graflex Plateholder
The mountcard was painted with black acrylic paint to give a matte finish, and I also numbered the adaptors with small notches in one corner, to identify which plates were shot in which holders, not entirely necessary, but potentially useful.

Detail with numbering notches (underside)
I also made some adaptors to use quarterplate-sized plates in 4x5 holders, with the same method of contstruction, which, although I could shoot in my Ensign Folding Klito, meant I could use the lenses and movements of the MPP Micro-Technical Mk VI with the effect of a small amount of cropping. As well as these technical considerations, the fact that glass plates in the quarterplate size (4 1/4 x 3 1/4, or 10.8x8.2cm) appear to be most abundant, it seemed wise to able to shoot this size in more than just one camera (the first couple of results with 1940s Ilford HP3 plates are below).

Ilford HP3 4 1/4 x 3 1/4 inch glass plate.
Shot with MPP Micro-Technical Mk VI using adaptor.
Ilford HP3 4 1/4 x 3 1/4 inch glass plate.
Shot with MPP Micro-Technical Mk VI using adaptor.

Saturday 5 April 2014

Some odd-sized glass plates

Ilford HP3 6x13 plate box
In my blog post 'A box of vintage plates and paper' I listed amongst the contents one of the HP3 boxes as "One box with 'paddle steamer' trademark, stereo plates 6x13cm (?) size." I have a box of identical dimensions of unopened Ilford Selochrome plates, which are labelled on the outer wrapping 6x13cm, a stereo plate format. However, opening the box in a dark bag to investigate, I found that the plates inside were rather shorter than the box suggested. I sacrificed one plate to the light to be able to measure it accurately. The plate was 6cm by 10.8cm, but had evidence of having been cut down or clipped by hand - one of the short sides had a rather rough edge (I'm actually surprised by how rough and haphazard the edges of some of the glass plates I've used has been). I imagine that the plates had been cut down in such a way that they could be fitted or used inside quarter-plate holders. I could have done this with my Ensign Klito, but instead chose to make adaptors to use the HP3 plates in 5x4 inch plateholders, and shoot them with my MPP Micro-Technical camera. I shot a first plate from this box without having made any tests, but having used HP3 plates of a similar age before, I thought that given a long enough exposure, I would get a result.

10.8x6cm HP3 plate, first exposure, MPP Micro-Technical Mk VI with 150mm Xenar
I gave the plate a generous twelve-minute exposure with the lens wide open at f4.5. The resulting negative was perhaps over-exposed, but there was plenty of detail and, without any sources of light inside the frame, there were no blown highlights. Although shot using a tripod, there is a bit of camera shake: during the exposure, a car stopped directly in front of the camera and the driver leaned out to ask me directions to a well-known nearby shopping centre. During this exchange I had to keep the darkslide in front of the open lens to preserve the scene. As the plate didn't fit in my Combi-Plan tank, I simply dropped it into a Patterson 3-reel tank for stand development, with the emulsion side facing the tank's outside edge.  I subsequently made a test but this wasn't entirely necessary: as I have found with some of the glass plates I've used, a combination of long exposures, inherent latitude, reciprocity law failure, and the compensating effect of stand development (plus some fog from age), all help to make for a large margin of error.

10.8x6cm HP3 test plate, MPP Micro-Technical Mk VI with 16.5cm Tessar
I metered the plate for the test at 25, and made three exposures by progressively withdrawing the darkslide. On development, I found I'd loaded this plate back to front, with the anti-halation backing facing the lens and imparting a texture to the image. However, it was clear that the plates were still very usable, and I shot the rest of the plates over the next few weeks.

HP3 plate, MPP Micro-Technical Mk VI with 16.5cm Tessar
HP3 plate, MPP Micro-Technical Mk VI with 150mm Xenar
HP3 plate, MPP Micro-Technical Mk VI with 16.5cm Tessar
HP3 plate, MPP Micro-Technical Mk VI with 16.5cm Tessar
HP3 plate, MPP Micro-Technical Mk VI with 150mm Xenar