Okay, I'm not really a new user, but this sure feels like a new user question,
so bear with me.  :)

I've got a really simple scene defined only by a camera and a cylinder (with
ambient 1 texture, so no light needed).  The camera is defined thus:

camera {
   location    <0, 0, -10>
   up          y
   right       (image_width/image_height)*x
   look_at     <0,0,0>
   angle       30
}

....and my cylinder thus:

cylinder {
   <0,-1,0>, <0,1,0>, 0.0125
   texture{pigment{color rgb 1} finish{ambient 1} }
   translate <0, 0, 0>
}


Obviously, this places the cylinder in the center of my otherwise empty scene.
I want to move the cylinder out to the *very* edge of my field of view.  I
expected this to be simple -- based on the scene geometry, I'd move my cylinder
out to 10*sin(15*pi/180) (which is about 2.59) in the x-direction:

translate <10*sin(15*pi/180), 0, 0>

However, I find that the cylinder is NOT right on the edge of my FOV, but
appears to be about 3.4% short.  If I adjust my translate value to:

translate <2.68, 0, 0>

....then it appears where I expected.

So, the obvious question is: what am I failing to account for?  Is there a
camera default that I'm failing to set?

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How Camp <hac### [at] gmailcom> wrote:
> translate <10*sin(15*pi/180), 0, 0>

The problem is that you are using sin() instead of tan(). I'll leave it
as an interesting exercise to figure out why the latter is correct.

-- 
                                                          - Warp

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Warp <war### [at] tagpovrayorg> wrote:
> The problem is that you are using sin() instead of tan().

Blush.  Thanks, Warp, for not crucifying me over such a dumb mistake.  :)

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