Controlling exposure in photography is challenging for some students to wrap their minds around. There are three settings that work together to control motion, light, depth of field, and quality of the overall image.
Shown in the image to the right:
- Math required to take a photograph with multiple exposures
- Black room or space without light
- Camera settings (10+ second shutter, aperture to capture motion, low ISO)
- Lighting instruments (flashlight, phone light, flash, lights flicked)
- Choreographed movement for subject
- Covering for camera vs. uncovered camera between shots
Note: The information presented at the above mentioned example (shown left, here) encourages the use of a strobe flash to achieve the shown effect. However, a strobe flash is not required. Students should instead focus on the use of a manual shutter using a black card or even the photographer's hand to block light as the subject moves to each position.
The technical elements are shown at the right. Note the four separate positions without blur in between. The photographer did a 25 second long exposure (for both examples shown above) with 4-5 seconds per position. He then covered the lens for a second to allow the model to transition to the next pose. Repeat.
This student used a motorized board to move himself forward without having to change positions. He chose to leave the shutter open during transitions to create the streak. You can tell where he held still for longer because his image is much clearer. He shot with a 15 second exposure for all the images shown above.