Well – a very nice and totally unexpected surprise this morning (thank you Jim!) when I opened the EPOD (Earth Science Picture of the Day) page and saw my pinhole camera image of the Sun’s path across the sky. Taken using a beer can as the pinhole camera (long axis vertical!) the image shows the Sun’s path across my southern horizon over a period of 6-months from the Summer Solstice (June 21st 2010) to the Winter Solstice (December 21st 2010). The light coloured object in the lower foreground is the fibreglass dome of the New Forest Observatory, and the light (banana-shaped) object in front of that is the cedar garden table which is actually oval in shape. The reason for using a beer can as the pinhole camera is that it is the perfect size to take the 5 x 7 inch Ilford photographic paper that records the image – you curl the paper around the inside of the beer can and there is a 5mm gap where you place the pinhole). Do not sand off the burr of the pinhole, you need to be able to feel it on the inside of the can when you load the paper (in the dark of course) so that you don’t accidentally cover the pinhole with the paper! What is amazing about this process (Justin Quinnell gives full details on his web site) is that you don’t need to develop the photographic paper. The pinhole image “burns” itself into the paper over the 6-months of exposure time and all you need to do when removing the photographic paper from the pinhole camera is to quickly get it into a digital scanner to “lift” the image off the paper.
I have two more pinhole cameras currently imaging my southern horizon – but these are made from tin tea caddies (also a perfect size for the 5 x 7 inch photographic paper). The main difference with these cameras is that this time the photographic paper is FLAT within the camera rather than curled round as it is in the beer can. This means I will get an undistorted view of the Sun’s path across the sky this time – just have 5-months to go before I can see the result 🙂
