What is it?
I’m often asked when I’m out and about photographing what that strange looking lens is I have attached to the front of my camera.
Well, it’s a homemade tilt/shift lens, aka a homemade Lensbaby, and I love using it, the effect it gives, particularly in black and white, is very distinctive, almost old-fashioned, and it also solves all sorts of problems when out practicing street photography here in Germany.
A modern camera can take most of the stress out of taking pictures, every shot is in focus, every exposure almost perfect, things can quickly start to get rather clinical though, and this is the great appeal of using such a lens, that it brings back an element of manual skill to the process.
It may be called a tilt/shift lens, but it’s actually more akin to free-lensing, whereby there is just a single plane of focus through the image and everything else quickly goes out of focus, and because the lens is only loosely attached to the camera with a length rubber tubing, there is a great skill in positioning the plane of focus within the frame, whereby it becomes more of a compositional tool.
It’s a useful effect for street photography here in Germany, because the copyright of the own image is so strong here, theoretically you need the permission of everyone who is recognisable in the frame every time you press the shutter, which makes any photography in a public space very difficult indeed.
So, the ability to defocus almost all objects or people not the direct subject of the photograph is extremely useful.
But above all, it’s great fun to use.
How does it work?
I should mention that I own a micro four thirds (M4/3) camera, a Panasonic Lumix G70, it has a reduced sized sensor with a crop factor of 2 and was designed with the intension of being able to use, with the aid of adapters, legacy lenses.
To ensure that camera specifications can be reliably compared, they are usually given in terms of an analogue 35mm film camera, so a full sized sensor has the dimensions 36mm x 24mm, which means that the lens has to cast an image circle with a diameter of of at least 45mm to cover the sensor’s diagonal measurement of 43.3 mm.
This means that the same image circle from a standard full frame lens will easily cover the M4/3 sensor at 17.3mm x 13mm with a diagonal of only 21.6mm, and so because the M4/3 has dimensions half of that of a full framed sensor, it has the effect of doubling the focal length of the lens, hence the crop factor of 2.
And this works to the advantage of the M4/3 still further when constructing a primitive tilt/shift lens, because the image circle is large enough to accommodate rather large angle changes of the lens when searching for the desired effect.
In the above illustration figure A shows the image circle cast from a standard full framed lens onto both a full framed and that of an M4/3 sensor, note that because the lens is mounted in the standard position, that there is no distortion on the sensor, the whole image is in focus relative to it.
Figure B however shows the same lens tilted at an angle whereby the only point at which the image is still in focus is the single plane running down from the point of intersection, everything else quickly runs out of focus. Note also that because of the tilt, that the image circle is no longer symmetrical and also no longer fully covers the full framed sensor, but that it still easily covers that of the M4/3.
I constructed mine from an old 28mm Canon lens, and with the crop factor of 2, it’s as though I were using a 56mm lens, almost perfect for street photography.
Here are the online instructions I used as inspiration when building mine, I bought a cheap Soligor 28mm, 1:2.8 lens for Canon on eBay for €20, I bought the adapter for under €10 on Amazon and just used a length of old bicycle inner tube I had hanging around the place to join them both together, it’s got better technical specifications than the Lensbaby and was made for maybe a tenth of the cost:
Here’s my tilt/shift Flicker album:
The Lensbaby website:
And an explanation of how a tilt/shift lens works:
© Andrew James Kirkwood – 2016