A successful photograph requires properly calculated exposure.
Most digital cameras have built-in light meters that automatically calculate the exposure. Film photographers and those digital photographers who prefer to work in the creative modes -- manual, program or aperture/shutter priority -- need to learn the mathematical processes, or get out the paper and scissors for an arts-and-crafts project that makes figuring proper exposure a simple twist of a dial.
Instructions
Create Shutter Speed Circle
1. Using the compass, bowl or cup, trace a large circle onto the poster board and cut it out. An 8 in. diameter provides ample space for 12 equal sections while still being compact enough to carry in your camera bag.
2. Measure with the ruler to divide the circle into 12 equal, pie-shaped segments. At the top of one segment write "shutter speed."
3. Moving clockwise from the shutter speed segment, write 11 more headings in this order: 1/1000 sec, 1/500 sec, 1/250 sec, 1/125 sec, 1/60 sec, 1/30 sec, 1/15 sec, 1/8 sec, 1/4 sec, 1/2 sec and 1 sec.
Create Aperture Circle
4. Trace a second circle, approximately 2 in. smaller in diameter than the shutter speed circle, and cut it out.
5. Measure with the ruler to divide the circle into 12 equal, pie-shaped segments. Write "aperture" on top of one segment.
6. Moving clockwise from the aperture segment, write the following titles in order: f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22 and f/32. In the last two sections, write "add more light."
Pin Together
7. Place the smaller circle on top of the larger circle, and poke a hole through the center of both. Place the brass fastener in the hole and secure the pin.
8. Spin the wheel to line up the shutter speed and aperture headings.
9. Move the aperture wheel to find its corresponding shutter speed and enter the value into the camera for a correct exposure.
Tags: segment write, shutter speed, aperture segment, circle into, circle into equal