More along the same lines (thanks to new SLAS member OPatricia Peterson for telling me about them): http://www.wham1180.com/pages/chetwalker.html?article=8719498 I especially liked the one with the two kids playing catch with the Moon. :) patrick On 14 Sep 2011, at 14:25, daniel turner wrote:
I just lifted this picture from spaceweather.com. It shows a whimsical picture of a type often seen around the harvest moon.
http://www.slas.us/gallery2/main.php?g2_itemId=4683
Its fun to shoot pictures like this but I like to figure out how far the camera was from the subject. It's easy but involves a little math.
The wheelbarrow bed is about 40 inches long and the moon looks to be about 3/4th of that wide. We know that the moon is about a half degree wide. half a degree time pi and divided by 180 gives .0087 radians. One over radians gives 144. That times the 30 inches the moon appears to be wide give 3437.7 inches. Divided by 12 gives 286 feet. thats the rough distance between the camera and the wheelbarrow.
Some times the subject is much farther away, like a climber on the side of a mountain or a car on a hillside. but the point is that the picture contains the information you need to find where the camera was at the time of the photo.
DT