[Leica] Angle of View

[red735i at verizon.net (Frank Filippone)]

I have always been fascinated by different angles of view of camera lenses.
Why manufacturers offered specific sets of focal lengths.

And it always amused me that the specs usually call out the diagonal angle
of view rather than the horizontal, as I think the horizontal is more
relevant to the user.

 

I looked up the different Leica focal lengths ever offered ( the 180 was a
limited production lens, but I threw it in anyway) 

For 35mm Film proportions,  the horizontal angle of view is

12mm   113 Degrees

15        100

16          97 

18          90

21          84 

24          74

25          72

28          65

35          55

40          49

50          40

73          28

75          27

85          24

90          23

135        15

180        11

 

One conclusion is that to get more "difference" the wider you go, the more
you need to make it appear that there is a difference.  ( a 24 mm lens does
not appear to be that much wider than a 28, but a 90 appears a lot wider
than a 135 although the angle of view difference is about the same)

 

Which explains, to some degree, why certain combinations of focal length are
more popular than others..

Other than in use for architecture, separating the angle of view by a "bit"
is more relevant, as the alternative is to take a step back or forward.

 

On our next trip, I will use this table to choose lenses.. Knowing that we
will not be in tiny lanes and tight squares ( as in our last 2 trips), and
will be focusing on larger areas of landscapes in general, I will go longer
than before.

 

Frank Filippone

Red735i at verizon.net