Photography: linear distortion problem?

Question

Hi I'm very confused with a test i have about linear distortion.

Q. Which of the following is one way to avoid linear distortion when photographing a building with a SLR camera.

a) Using a CAT lens
b) Using a PC lens
c) Being sure to stand very straight
d) Tilting the entire camera up, so that
the top of the building is visible in the viewfinder

I know that a and d are not.
I could use a PC lens, but also stand up straight. What would be the proper answer?
Any comments will be appreciated thanks!!!

Answer 1

Well standing straight up will have little to do with avoiding linear distortion - the "falling backwards" look commonly seen in photographs of buildings.



To avoid the "falling backwards" effect the film or sensor plane must be parallel with the building. This requires using a very wide angle lens or a PC or tilt/shift lens. The problem with the wide angle solution is usually the inclusion of a lot of "extra" space - both foreground and sky. The PC or tilt/shift lens allows raising the front element of the lens above the film/sensor plane thus allowing a more parallel alignment.



There is also software that allows you to correct the "falling backwards" effect thus decreasing the need for a PC or tilt/shift lens.

Answer 2

Linear Distortion Photography

Answer 3

The answer is B.



Perspective control and Tilt Shift Lens allow you to capture architecture without linear distortion.

Answer 4

I don't like ANY of those answers. Number 3 is most definitely NOT the answer to pick, that kind of tilting is what CAUSES the distortion. Number 2 is as fhotoace said, only good if the camera is level and square with the lines of the building, so the answer in and of itself is also not correct without further explanation. Number 1 sounds idiotic, but is actually about the most accurate answer. If by "stand up very straight" the meaning is to keep the camera level and square with the building, then it is the correct answer. steve