On Sat, 6 Sep 2003, Mac Oglesby wrote: > 107:1 seems to be the ratio between the projection distance from a > pinhole to a screen and the diameter of the Sun's image. That is, the > diameter of the Sun's image will be about 1/107th of the distance > from the projecting pinhole. > > Since a pinhole image is very dim, for brighter images, the ratio > between the projection distance and the hole diameter is recommended > as ranging from about 200:1 to 400:1. > > Hope this helps. > > Mac
Isn't that reversed, Mac? If the image is too dim, you would want a larger pinhole, not a smaller one, as 200:1 or 400:1 would indicate... Dave -