At the back of a cupboard I came across a bottle of SE1 Emulsion. It was the remains of the emulsion I had used when I last coated a batch of glass plates, way back in July 2016 and even then it had been several months since the bottle was first opened. From my notes on the box, the emulsion was diluted with 16% Photo-Flo and amounted to about 50ml. I wondered if it would still work.
With Worldwide Pinhole Day 2018 just six weeks away, I have also been trying to think of something new (at least to me) to do this year. How about preparing and coating the inside of a glass marmalade jar with a pinhole in the lid, to create an anamorphic image around the inside of the jar that could be viewed from the outside? It’s not such a crazy idea but subject matter would need to be carefully chosen and exposure might be tricky.
I made up a small quantity of gelatin (1g in 200ml water) with chrome alum hardener (4ml of 2% solution in water) to sub the inside of the cleaned glass jar which I did by pouring in the hardened gelatin solution and flowing it over the entire area by gently rolling and rotating the jar before pouring away the excess. The jar was left aside to air dry, ready for coating with emulsion.
To protect the emulsion from light, I prepared a two-part light-seal from black card and Duck Tape. The jar would fit into one piece and a second piece with a hole in the top for access to the pinhole, would slide down over the first and the hole sealed to the lid of the jar with black PVC tape. A pinhole was punched/drilled into the centre of the lid and a piece of black PVC tape used for a shutter. From a high resolution scan of the pinhole I measured its diameter as 0.37mm.
Now sometime over the winter I had tidied out some of my early glass plate attempts, cleaning off the images by immersing them in very hot water and bleach, scrubbing them clean and then re-subbing them ready for re-use. The 50ml of emulsion that I had would cover quite a bit more than the marmalade jar so I used the excess to coat a few glass plates too: four each of 5×4 (for my Intrepid plate holders) and of 5×3 (for my pincam constructed for WPPD2014). Coating the marmalade jar was achieved in the same fashion as I have already described for subbing it. The coated jar and plates were left in a cool, dark place for a few days to dry completely.
With everything prepared, I was now ready to test out whether my well out of date, diluted emulsion would still work. I planned to set the jar on the floor of my old garden shed, thus exposing an image of the underside of the shed roof on the base of the jar and the shed interior around the sides. By way of a check I would also expose a plate of the outside of the shed, in the WPPD2014 pincam.
From past experience I rated the emulsion at ISO 5. For the shed interior I metered EV(100) 8 and thus a 60 minute exposure, and for the outside of the shed EV(100) 13 which gave a 2 minute exposure.
For developer I used Ilford Multigrade diluted 1+19 at approximately 20ºC. The marmalade jar image was developed, as for subbing and pouring, by pouring developer, stop bath and fixer in turn into the jar and swilling it around to cover the surface. Fixer was poured back into the jar and left to stand until the image cleared. The plate from the WPPD2014 pincam was tray developed as normal. Both the jar and the plate were then rinsed in fresh water for a couple of hours before being left to dry.
Unfortunately the marmalade jar image was completely overexposed. The fact that the emulsion is black at least tells me it was still ‘active’ and it is just possible to make out some faint detail in the dried image.
On the other hand the plate from the WPPD2014 pincam was perfectly exposed!
I’m glad to have decided to expose a plate as a check. It tells me the emulsion is still good and that I need to be more careful with my metering for the marmalade jar. For the marmalade jar exposure I think I was fooled by the amount of light entering via the windows and door (which was left open during the exposure), having metered for the dark recesses of the shed. Unfortunately I only prepared one jar so it will be a wee while before I can have another go … but there’s still plenty time before Pinhole Day!