If you've ever wanted to tilt or shift, if you've ever wondered what the hell it was and what would happen if you did it...now's your chance. In Part 1, what is it, what does it do and how. Coming up in Part 2, how to make your own tilt shift lens and what to do with it!
What is it?
The first thing to point out is that tilt and shift are two very different things used for very different reasons. I have a feeling that lomographers are more likely to want to tilt than to shift, so lets get shifting out of the way first.
Have you ever noticed that when you take a picture of a large building close up, something strange happens to the building – it looks a bit distorted, the outside walls seem closer together at the top than at the bottom?
This is because, to get the whole building into the picture, you had to hold your camera at an angle to the building, the top is much further away from you than the bottom. And as we know, things that are far away appear smaller than things that are close up, so the top seems smaller than the bottom. (anyone but me thinking about the scene from Father Ted right now…this cow is small, but those cows are faaaar away)
Us lomographers don’t really mind this, but architects or architectural historians find it annoying. They want the building to look square and straight, and not like it’s about to fall backwards, so they use a shift lens.
A shift lens is a lens that is attached to the camera body but which can move up and down on little rails, so you can shift the lens up, fitting more of the building into your picture without have to hold your camera at an angle. Voila, your building is once again built on parallel lines and not about to fall over.
To understand why a tilt lens works, all you have to remember is that your camera is built to ensure that the lens plane (the glass in your lens) and the image plane (the film in your camera) are always, always, always parallel. This is so that the when you focus on something five metres away, everything five metres away is in focus. You get all of your friend, the tree, your feet etc nicely in focus because it’s all exactly the same distance from your lens and the film in your camera.
A tilt lens allows you to move the lens so that it’s not parallel to the film, and when you move the lens, you move the focal plane (the bit in focus). And, bizarrely, the focal plane is now neither parallel to the lens or the film (there’s maths involved here that I don’t understand, but if you’re that way inclined you can read about it here: http://en.wikipedia.org/wiki/Scheimpflug_principle )
Practically, what it means is that your friend, five metres away has a head that’s in focus and a shirt that’s wildly out of focus. Or one foot in focus and the other out of focus. As a home-made tilt lens is usually fixed to the camera with something very flexible so that you can tilt the lens four ways, choosing exactly what you want to be in focus in your shot.
Well, selective focus and messing with the depth of field (how much of your shot is in focus) is a lot of fun – you can pick out tiny details anywhere in the frame, like a baby’s face or hands and have them in focus while everything else is just a blur.
And you can try to shoot fake miniature scenes too, find a nice high viewpoint, a bridge, a roof, the top tier of a football stadium, start tilting your lens and see what happens…
Coming next: in part 2, how to make your own tilt shift lens…..