[LRflex] Re: PS RE: Angle of View

........ using angle
of view in the sense of the angle of the apex of the
cone of light that is projected, .........
Perhaps angle of coverage is a
better term for what I was talking about.  


This is what I learned to call the image circle.  It is the projected
diameter of the cone of light. 



Generally,
a different lens formulation gives a different angle
of coverage, which in combination with focal length,
determines coverage for different formats
You were
using the angle of view as in relation to the diagonal
(or possibly horizontal or vertical angle of view) for
a particular size of sensor or film, in essence, we
were looking down opposite directions of the cone of
light.  


I agree....

The specification that is in use that is similar to
Doug's proposal is "35mm equivalent focal length", but
is expressed in focal length referenced to a 24x36mm
film/sensor size, instead of angle of view.  Doug's is
more useful in terms of referencing in degrees that
you are viewing. 

Alternatively, you could reference magnification
ratio, which refers to the size of the image on the
sensor, but that would really confuse people!


Like they are not enough confused, already!


The real problem is that the marketing types thought the words "lens factor
multiplier" or similar, would make it easy for the market to understand.
Maybe it did, but using a term incorrectly always bothers me.....and in the
long run, fails.

I like the angle of view concept.... it is easily understood, and is sensor
size ( and technology) independent.

Let's try, maybe we can get Leica ( at least) to adopt it.....

Frank


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