F-STOPS OR F-NUMBERS AND CLICK STOPS

There is a white dot next to the maximum f- number engraved on the lens's aperture ring on many Pentax lenses. This white dot indicates an aperture which is darker by one stop (larger number). The illustration below shows the white dot next to f/4.5 is f/5.6.

The click stops between two engraved f/stops are equivalent to intermediate f-stops. Some lenses do not have an intermediate click f- stop on the aperture ring due to limited space between the f-numbers engraved on the aperture ring.

1.4 2 2.8 4 5.6 8 11 16 22 32 45

1.2

1.7

2.4

3.4

4.8

6.7

9.5

13.5

19

26

38

8