On Apr 12, 7:25=A0pm, skippy-...@[EMAIL PROTECTED]
( ) wrote:
> Camera plane.....The camera plane is a horizontal line that runs
> directly across the camera position as it relates to the positon of the
> subject. The subject is at the center of a circle and the camera is at
> the outside edge of the circle so we are able to move lights around an
> invisible circle at different degrees
>
> I am having a hard time grasping this..
>
> Thanks for any help
It is vague trying to determine what it means without context, but I
think I understand it but where are all the physicists and engineers
when we need them?
Assume the subject is point and you are X' from the subject. Assume a
circle around the subject with a radius of X'. Assume a line touches
the circle at one point and one point only. That line is, IIRC,
called a tangent.
It doesn't matter where the line and the circle intersect at the one
point, but the point has a few interesting characteristics. First
off, a line from the center of the circle to the point of intersection
crosses the line at a 90' angle.
Now lets work this backwards. If the subject is where it is and
camera is where it is, you can draw a circle around the subject and
have the circle intersect the camera. Now, if you were to point the
camera directly at the subject, you are then creating the line from
the center/subject to the circle at one and only one point. The line
that would intersect at that point would be exactly 90' from the line
from the camera to the subject. And yes, it would be a line because
you're dealing with the exact center (a point)
If practice, all of this already exists. On an old film camera, the
film was at a 90' angle to the lens. Now it is the sensor but that's
harder to see. That's the film plane and it's a plane because the
film isn't a single line -- it's a solid. That plain (or the plane
made be the back of your camera) is a pretty good approximation of the
line described earlier.
Good luck with it.
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