In a message dated 9:11 PM 11/29/00, Bill Gottesman wrote:
(snip)
I would like to suggest that if you
use a pin-hole, that the aperture be parallel to the dial face. This may
seem obvious, but it wasn't obvious to me 2 years ago. This way a round hole
will always cast a round image, and will not spread into an ellipse as the
angle of the sun changes.
(snip)
Bill,
I need some help understanding this. It seems to me that, using a
round hole aperture in a plate parallel to a vertical dial plate, the
sun's cast image will never be circular unless the sun is at the
horizon. What am I missing?
Best wishes,
Mac Oglesby
43 N 72.5 W
