Your tilt-shift lens: more than just a miniature effect maker
Everyone has probably heard of tilt-shift lenses. A tilt-shift lens is named as such because it has a ‘tilt’ mechanism that changes the angle of the lens relative to the body, tilting it to the left or right, or up or down. It also has a ‘shift’ mechanism that shifts the lens up or down or from side to side.
The tilt mechanism on a tilt-shift lens can be used to keep the whole of a subject in focus when it’s at an angle to the camera. It’s based on the ‘Scheimpflug Principle’ – see the diagrams in our photography cheat sheet below.
Tilt-shift lens effects are perhaps most popular for creating the ‘miniature’ effect you see everywhere these days, which is achieved by tilting the lens the ‘wrong’ way to make the depth of field more shallow.
This tricks you into thinking you’re looking at a diorama rather than a real scene. Usually these effects are created using digital blur rather than lens movements, but Lensbaby lenses use a low-tech tilt movement to achieve the same effect optically.
Shift movements are used when you need to include objects outside the current field of view, without having to tilt or rotate the camera (for more, see these 5 things you need to know about tilt-shift lenses).
A common example is where you’ve got the camera level to prevent converging verticals, but the top of the building is cut off. If you shift the lens upwards, the top comes into view, but the camera stays level.
You can also use a ‘sideways’ shift to avoid obstructions. You position the camera so that the obstruction is out of the frame, then use the shift mechanism to bring your subject back into the centre.
Lens movements are nothing new. Old-fashioned large-format cameras had them built in. On many models you could apply tilt and shift movements to the lens panel and to the back, which contained the film.
This degree of flexibility isn’t possible with DSLRs and their lenses, though. The movement can either be from side to side or up and down, not both at once. In fact it’s a single movement, and you rotate the body of the lens to swap it from vertical to horizontal.
There are other practical considerations with these lenses. The complexity of the movements means that you sacrifice autofocus, and they are very difficult to use effectively without a tripod. It’s almost impossible to make accurate adjustments to the tilt and shift axes unless the camera is completely stationary.
But despite the drawbacks, a tilt-shift lens is invaluable for architectural, commercial and even still life photography. It’s true that you can correct converging verticals digitally in Photoshop, but this is no substitute for recording an optically-correct image in the first place, and there is often some visible loss in quality (see also how to fake a tilt-shift effect in Photoshop Elements).
So while perspective control lenses like these have their roots in plate cameras, they still have an important role today because they change the optical geometry of the image and the spatial relationships between objects in ways that Photoshop can’t.
In our latest photography cheat sheet below we’ve illustrated how a tilt-shift lens can be used to correct some of the common photography problems that plague many photographers.
To view the larger version of our tilt-shift lens photography cheat sheet, simply click on the infographic below to expand the file. Alternatively, drag and drop it to your desktop.
Digital camera effects from A-Z
Photoshop Effects: how to mimic studio lighting for stylish portraits
16 tips for abstract architecture photography
Set up and shoot pictures of buildings like a pro
Free architecture photography cheat sheet
on Friday, September 21st, 2012 at 2:00 am under Photography Tips.
Tags: lenses, photography cheat sheet, tilt-shift