Question

The aerial photograph made with the optical axis coinciding with the direction of gravity is

• A. Tilted photograph
• B. Vertical photograph
• C. Terrestrial photograph
• D. Oblique photograph

Hint:

Aerial photographs are classified by the orientation of the camera optical axis relative to the vertical (the direction of gravity, the plumb line).

Answer 1

The Correct Option is B

Step 1: Understand the key idea.
Aerial photos are named by how the camera's optical axis is pointed compared with the vertical, that is the direction of gravity.

Step 2: Recall what gravity direction means.
The direction of gravity is the plumb line, pointing straight down to the earth. A camera looking exactly straight down has its axis along this line.

Step 3: Check the tilted and oblique photos.
A tilted photo has the axis a little off the vertical, and an oblique photo has it tilted a lot, so neither matches a perfectly vertical axis.

Step 4: Check the terrestrial photo.
A terrestrial photo is taken from the ground with the camera roughly horizontal, so it does not fit either.

Step 5: Match the vertical photo.
When the optical axis lines up exactly with gravity (truly vertical), the photo is a vertical photograph.

Step 6: State the answer.
The photograph is a vertical photograph.
\[ \boxed{\text{Vertical photograph}} \]