On 05/05/2014 14:03, Bill Gottesman wrote:
Here is what I think:
The can is laying on its side with its axis oriented north-south. A
pinhole is made on the west side of the can (assuming this location is
in the northern hemisphere, and that the zenith of the sun is toward
the south), pointing upward at about 45 degrees. It captures the sun
before it has reached solar noon, then tracks it all the way to sunset
in the west. The tracks of the morning sun at the top of the picture
appear to converge; this effect comes from that edge of the film being
so close to can's the pin-hole, where all light rays converge at their
origin. (The film is wrapped around the inside of the can)
-Bill
More conventional sunrise to sunset six month pinhole camera solargraphs
periodically appear at
www.space-weather.com (and of course Google will find loads more)
--
--
Richard Mallett
Eaton Bray, Dunstable
South Beds. UK
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