Joe Liburdi’s School of U/W Photography
Shooting ambient light means you are using available natural light only. It is a technique used for shooting large fish, wrecks, reefs and silhouettes. Ambient light imaging is best done in clear water at depths of 20 feet or less.
Setting a proper exposure. There are three elements that effect exposure: (1) ISO (2) Aperture (3) Shutter speed. You can set your camera to Program Mode and not have to worry about any of these, but you may not be satisfied with the results and you certainly aren’t being creative.
- ISO: ISO calculates how much light is exposed to the sensor. The lower the number, the less amount of light recorded. The higher the number, the greater amount of light recorded.
- Aperture priority mode: You select the aperture and the camera selects the shutter speed. Aperture is the adjustment that determines how large the lens opens/closes. The large numbers, like f/11 to f/32 represent small lens openings with less light striking the sensor. The small numbers, like f/3.5 to f/8 represents large openings with more light striking the sensor.
- Shutter priority mode: You select the shutter speed and the camera selects the aperture. Slow shutter speeds result in more light striking the sensor over a greater prior of time. Slow shutter speeds below 1/60 create blur or motion in photos and required a tripod/steady hand to hold the camera still. Fast shutter speeds result in less light striking the sensor and stops action.
How ISO, Aperture, and Shutter Speed relate to one another. If you change one, you must double the other for a correct exposure. Example:
| Shutter |
F/Stop |
ISO |
| 1/60 |
f/8 |
100 |
| 1/125 |
f5.6 |
100 |
| 1/250 |
f/4 |
100 |
| 1/250 |
f5.6 |
200 |
Tips for Point-and-Shoot cameras (All Auto) with no Manual Mode Features
- Set camera at Auto White Balance. Note: If available on your camera, experiment with white balance set at “cloudy/shade.
- Experiment with ISO between 100 to 400. Note: Higher ISO with smaller compact cameras produce more noise.
- If your camera has the Underwater Mode, use it only in 15 feet or less. If your camera does not have the Underwater Mode feature, you must use a color correction filter to enhance the red, orange and yellow below 15 feet. Good source for the filters are UR Pro and Magic Filters. Do not use any strobe light when using the Underwater Mode/color corrections filters. Doing so will produce a brown cast to the image.
Tips for cameras with Manual Mode Features:
- In manual mode you have the opportunity to select aperture and shutter speed
- Use the tips above to set white balance and ISO.
- In manual mode begin by setting the shutter speed at 1/125. Experiment with higher speeds to freeze action. Set camera at f/8. Experiment with lower/higher f/stops to get the right exposure. If your camera has a light meter/histogram uses it to determine the right f/stop to use.
© Joe Liburdi 2011
