what is it?
I first came across homemade tilt-shift lenses on Orbit1.com but have since seen one on verba.chromogenic and a couple of other places too (see the bottom-right of this page for some further links), but it was this article on digihack.net that finally convinced me to give it a try.
The basic idea is that the lens should be able to move independently from the camera body allowing you to alter the plane of focus (tilt) or change the perspective (shift). This is the principle that the Lensbaby uses, but should give better results as the optics are of a better quality – at least that’s the theory.
Anyway, I managed to get hold of a cheap Carl Zeiss Jena DDR Biometar 80mm f/2.8 on eBay, so have built my own.
how to ...
There are numerous ways to make one of these lenses – John used the lens mount from an old 50mm lens, a film pouch and an enlarger lens, while Justin did much the same but substituted a garbage bag for the film pouch – but I’ve gone down the digihack route and used a medium format lens, a cut-out lens cap, and a rubber bellows; the latter of which started life as a steering-arm gaitor for a car. The gaitor was cut to provide a tight fit around the base of the lens and secured with a couple of cable ties, and the other end was glued and taped to a cut-out lens hood, and it seems reasonably sturdy.
This version will focus between around two feet (when fully extended) to a little beyond infinity (when compressed), the aperture can be changed between f/2.8 and f/22, and I’m reasonably happy with how it turned out. Version two, when I get around to it, will probably have a more flexible bellows system as this one is a little difficult to manipulate, particularly when hand-holding the camera, and I may well try and use an old lens mount rather than a body cap as I’ve already twisted the whole thing off the camera body a couple of times.
Hopefully that explains most things about this lens, but if you have any questions .