The Obscura 4x5 pinhole camera is Ilford’s second pinhole camera…
I don’t like to crop my negatives; in fact I almost always make my photographs by composing them to the very edge of the focusing screen and printing the whole negative. However there are times when a photograph needs to be a different size than 4 x 5. I’ve found that some subjects need to be in ‘panoramic’ format.
To achieve this without cropping the negative, I’ve made an adaptor that makes two 2 x 5 negatives on the one sheet of film. This is simply made out of a spare 4 x 5 dark slide that has a section cut out of it.
The dark slide measures 107 mm x 166 mm (not including the notched grip end). A piece is cut out leaving an ‘L’ shape. The piece removed is 53 mm x 130 mm, leaving a 34.5 mm end at the notched grip end. It’s very important that this is measured carefully as light will leak in the end if the measurement is incorrect.
The plastic dark slides are easy to cut with a fine saw, and are then lightly sanded. Older aluminium dark slides require a bit more care while cutting.
I’ve made up a mask that I tape on the ground glass focusing screen while composing (photograph below). If I’m using the top half of the film, I cover the bottom half of the focusing screen with the mask and compose the photograph. I then remove the (whole) dark slide and insert the half slide – covering the bottom half of the film – leaving the top uncovered. I make the exposure, remove the half dark slide and insert the whole dark slide.
I mark an ‘X’ for exposed – in pencil – on the film holder corresponding to the half of the film I’ve just exposed to avoid a double exposure.
For the second exposure the mask is placed covering the top half of the focusing screen, leaving the bottom uncovered, and the process is repeated exposing the other half of the film (main photograph above shows 2×5 adaptor exposing the top half of the 4×5 film).
You should end up with two 2 x 5 negatives on the one piece of film. Of course you can make vertical photographs too (photograph below).
The same process can be adopted to make two ‘panoramic’ exposures on the one sheet of film for any size large format film holders.
Galada Tamboore – Merri Creek Gorge. 8×20 print from 2×5 negative
Rapids, Galada Tamboore – Merri Creek Gorge. 8×20 print from 2×5 negative