Pinhole on a plate

It wasn’t the best of days for photography of any sort, far less for attempting pinholes on dry glass plates.

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It wasn’t the best of days for photography of any sort, far less for attempting pinholes on dry glass plates. A foreboding dark sky promised poor light and heavy rain showers. Rain was delivered as promised for most of the morning and into the early afternoon.

I was in East Lothian, meeting with a group of friends for a photowalk around Gosford Estate and then on to the shoreline at Longniddry Bents. Packed in my camera bag was the pincam I had made from foamcore for Worldwide Pinhole Photography Day 2014, a box of 5″ x 3 1/2″ dry glass plates that I had poured a couple of weeks ago and a changing bag. For a DIY pincam it is quite sophisticated, being fitted with a sliding shutter and a tripod bush so I also carried a tripod.

Within Gosford Estate we were well sheltered by the trees from the rain but also from what little light there was. Pinhole exposures would have been measured in hours never mind minutes or even seconds! There was just the one opportunity for a photograph, out of the trees and in front of the house. I gave it an exposure of 2 minutes and 20 seconds, metering with the Pinhole Assist iPhone App set for an ISO of 2.5 and assuming an aperture of f/180.

By early afternoon we could see the skies beginning to clear and as the rain eased off we headed to Longniddry Bents. I made only two more exposures, each of 1 minute and 20 seconds and made that do for the day. The plates in the pincam have to be changed between each exposure, a fiddly job involving placing the camera, the box of unexposed plates and a box in which to put the exposed plates all together in the changing bag. To further complicate matters the unexposed plates are separated by baking paper and enclosed in a  black plastic bag within their box. The exposed plates need to be packed similarly in the second box (which I identify by a thick card ‘X’ stuck to it’s lid). And it all has to be done by feel within the changing bag. It’s a time consuming business!

On my return home I set about developing the plates. I decided to use freshly prepared Ilford Multigrade at a dilution of 1+9. I wanted to make a comparison with the development of the 1/16th plates from The Countess that I had developed a few weeks ago in 4-week old, used developer. These had taken around  4 minutes to complete. What a difference fresh developer made. Development was very quick – too quick, with full density coming within 30 seconds and impossible to control.

It was also immediately apparent that the plates were overexposed. I suspect the aperture is actually wider than I had assumed, borne out by the images being softer than I would expect, and I recall fiddling with it some time after the pincam was last used. I’ve likely knackered it!

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The plates were well rinsed in baths of clean water and in Ilford Wash Aid and then left to dry. It took two days for the emulsion to dry fully. The emulsion was coated quite thickly and on each of the three plates it had obviously begun to gel as the excess was being drained off. This has resulted in a thicker coating of emulsion at the bottom of each plate (as I held it when pouring – it is seen as an opaque patch towards the left edge of each developed plate as viewed) that appears to have been too thick for the developer to penetrate. Perhaps with a weaker dilution to allow for longer development time, these areas would have yielded more image.

All in all I’m pleased with the results. Before I expose more of these plates I need to replace the pinhole in the pincam with a more accurately measured aperture. Next development I will use a more dilute developer: Old, used developer can work but consistent results cannot be counted on but if I can determine a satisfactory dilution of fresh developer, I can reproduce that each time.

The one remaining observation to note from this exercise was that the baking paper I had used to separate the coated plates had both absorbed moisture from the gelatin of the emulsion and left faint contact marks across its surface. I may have packed the plates too soon, before they were properly dry. I have unpacked the remaining plates and laid them out (in the dark) to allow them to dry more and will allow more drying time for future plates.

Author: Donald Tainsh

A lifelong explorer of photography

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