Tilt and shift lenses are highly specialized lenses for use with architecture
photography.
What are T&S lenses for?
When you take a picture of a tall building with a wide angle lens, the building
seems to be "bent" (in fact what you see is the lines of the building
converging on an imaginary point - much in the same way as you would envision
when you do perspective drawing
This is the way we are used to seing things, so we don't question it. For the
sake of architecture photography however, it is important
that the building is represented as well as possible, while losing as little
detail as possible. There are two ways of doing this:
- Stand on a great distance, at the same height as the building, taking
the picture with a telephoto lens
- Use a Tilt and Shift lens
What the T&S lens does, is that, apart from focussing and setting apertures etc, you set the shift height. This "bends" the building you
are trying to photograph. The trick, then, is to "bend" the building
the opposite way of what the eye sees. With some practice, you can make the
buildings seem perfectly straight.
Tilt = Horizental compensation
Shift = Vertical compensation
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With T&S Without T&S
The technical explanation of how a T&S lens work are a bit beyond me -
it can probably be explained mathematically (see http://www.a1.nl/phomepag/markerink/shifcalc.htm),
but it is much easier to see it for yourself.
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