Suppose you have an f/5.6 lens on your camera. If the lens has a 56-mm focal len
ID: 1280370 • Letter: S
Question
Suppose you have an f/5.6 lens on your camera. If the lens has a 56-mm focal length, what is its effective diameter? A. 5.6 mm B. 56 mm C. 10 mm D. 0.56 mm
A lens of speed f/1.8 has an effective diameter of 28 mm. What is its focal length?
15.5 mm
2.8 mm
5 mm
50 mm
Suppose you have a lens with effective diameter of 28 mm, with a speed of f/1.5. You want to double its
focal length, while keeping the same speed. What would the effective diameter have to be of the new lens?
56 mm
14 mm
19 mm
42 mm
A.15.5 mm
B.2.8 mm
C.5 mm
D.50 mm
Explanation / Answer
1.B. 56 mm
2.D. 50 mm
3.C. 19 mm