Question

The building shown in Picture 1 can look as it does in Picture 2 if photographed using: 

• A. Tilt–Shift Lens
• B. Mirror Lens
• C. USM Lens
• D. Stereoscopic Lens

Hint:

Leaning buildings? Keep the camera level and shift the lens up. If you must tilt the camera, expect converging verticals; only shift (or post-process perspective warp) brings them back to parallel.

Answer 1

The Correct Option is A

What changes from Picture 1 to Picture 2?
In Picture 1 the building’s vertical edges converge toward the top—classic “keystone” distortion that occurs when the camera is tilted upward (the sensor plane is no longer parallel to the building’s verticals). In Picture 2 those verticals appear parallel and upright; perspective has been corrected in-camera.

How to achieve this at capture time: the shift movement.
A tilt–shift lens allows the lens to be shifted relative to the sensor. The photographer keeps the camera level (sensor plane vertical), eliminating vertical convergence. To include the top of the building without tilting the camera, the lens is shifted upward, moving the image circle over the sensor. Result: the frame covers the building’s top while preserving parallel verticals—precisely the transformation seen in Picture 2.

Why the other options are wrong:
(B) Mirror lens (reflex): a catadioptric telephoto that yields donut-shaped bokeh; it does not correct keystone distortion.

(C) USM lens: “USM” is Canon’s Ultrasonic Motor for autofocus speed; it is a focusing drive, not an optical movement.

(D) Stereoscopic lens: captures two viewpoints for 3D; unrelated to perspective correction of verticals.

Tilt vs Shift (extra detail):
A tilt–shift lens has two independent movements:

Shift — translates the optical axis parallel to the sensor, used for perspective control (what we need here).
Tilt — angles the lens relative to the sensor to rotate the plane of focus (Scheimpflug principle), useful for selective focus or extended depth-of-field in product/architecture. Tilt is not what corrects the verticals; the correction is from shift.

Therefore the correct tool to obtain Picture 2 at the moment of capture is a Tilt–Shift Lens (specifically, using the shift function).