In order to access shutter speeds of less than 1s I need a mechanical shutter. I found one on eBay for a bargain price – and it is in good mechanical working order. The challenge was to attach it to the camera as the rubber seal has gone solid.
I first rigged a plastic adapter to put the shutter on the front of the lens. This did work OK, but isn’t very elegant. Next, I looked at putting the shutter between the lens and the camera body. I didn’t want to make too many cuts, or changes to the camera or shutter so fabricated a frame to hold the shutter onto which the lens could be mounted. I only needed to make 3 small screw holes into the lens mounting plate. This has worked well, so will now stain the frame to finish it off. Next step (in the next blog) is to measure/adjust the shutter so I know what speed it is running at.
I now have some 7″x5″ sheet film for the antique Thornton Pickard (Boots) bellows camera. Unfortunately the film/plate holders are slightly less than 7″x5″ so in complete darkness, using masking tape stuck to the bed of the guillotine as guides, I trimmed down the film to fit. What you see here is my third day’s experiments – Day one produced under-exposed images, day two over-exposed and today – just right (mostly). Setting up the still life by the kitchen window, I took light readings off each piece of fruit and the black paper backgroud – yielding recommended exposure times ranging from 4 to 30s at F32. As the 30s was for the black background I went for a 20s exposure and was very happy with the result. I used the same settings for my portrait shot.
Contact prints were made, experimenting with exposure here too. I am exposing using a flashgun held 45cm above the paper. The flashgun has a controllable intensity. – level 4 seems optimum – but doesn’t give quite the contrast I hoped for – I have ordered some filters on ebay to make the flashgun light more magenta as I have read this increases contrast – we’ll find out when they arrive.
One problem was the film/plate holders are old and fragile and some wood splintered off – the pieces that make them light-tight. So I had to make (using some mahogany veneer) replacement pieces.
The other problem I have encountered with these film holders is that the metal plates that sit in the middle separating the two pieces of film have springy pieces in the middle and these scratch the film and they don’t fit too well either. I am replacing these with stiff black paper and we’ll see how they perform.
My Day two efforts were outside – around Glastonbury – Godney. The light was too bright and I had to deal with exposure times of only half a second with this ISO 200 film even on F64. It wasn’t possible to accurately judge taking off and replacing the lens cap in these circumstances – though I did try. I have sourced on Ebay a shutter mechanism that will fit on the front of the lens allowing me to make theses shorter exposure times. Something to play with over Christmas 🙂
The iphone Lux app reading indicated F2.8 Iso 6 for 15s. In fact 2.25 mins was needed.
This needs investigation.
Interesting that since the paper negative is not sensitive to red light that the oranges in the RH image showed up as so dark. Still some work to do on focussing – though with such wide aperture the depth of field is going to be very shallow.