Some time ago I became fixated with the idea of making my own lens using a cheap plastic loup or magnifying glass. So I bought a packet of four plastic magnifying glasses for about £2 on ebay and set to work making my own lens.
The first task was to work out the focal length of the lens and this can be done by holding the lens against a white piece of paper (or in my case wall) and measuring the distance at which the image projected onto the white surface is in focus. It helps to be in a darkish room with a large window (the light source should be at an infinitish distance). I used this method to calculate that the focal length of the lens was 6 inches (approx.).
The next task was to decide which camera I was willing to sacrifice to this complex experiment. I have in my arsenal of cameras an old Kodak 44A and a Coronet Ambassador both of which I had already ruined trying to flip their lenses so I decided to try the Kodak first. The Kodak 44 is a 127 format camera and as I had about 5 rolls of Efke 127 film sitting idly in my study I chose the Kodak as my first attempt.
Next I had to design a casing to hold my plastic lens at the correct distance. As a child I was a disciple of Blue Peter and spent many a happy hour watching Valery Singleton make Christmas decorations from rubbish so the cardboard tube from a loo roll was the natural choice for material. I therefore cut one down to 5.5 inches, cut the roll lengthways so that it would fit around the diameter of the lens, glued it down and spray painted it black and taped it to the Kodak with gaffer tape. So there you have it, before you could say "get down shep!" I had a fully functioning Kodak 44 with a home made telephoto lens.
Next to try it out. Unfortunately in my enthusiasm to create my lens, I had overlooked one basic design flaw - the lens was 5.5 inches away from the aperture so that when I exposed a frame, the image produced on the negative was small and circular. In fact I only got one recognisable image from the one roll I shot, which was of three geese.
Not to be deterred, I then fixed my eye upon the Coronet Ambassador - the film in the Coronet is held about 5 inches from the lens, so the lens would only be about an inch in front of the aperture and therefore should fill the frame. I cut the cardboard tube to size and fixed it to the camera body with a light-proof seal of electrical tape. A photo of the finished article is below. You have to admire the craftmanship on this, Hasselblad - eat your heart out!
Anyway once I'd finished patting myself on the back it was time to test it in the field or in this case Santiago de Compostela. Below are a couple of images of that trip.
All in all not a bad effort - do I get get a Blue Peter Badge?
