Selection of diving light beam angles

15 Apr Selection of diving light beam angles

Firstly, what is the beam angle?

A beam angle is the measure of the spread of light from the light source. More specifically, it is the angle between the two directions for which the intensity drops to 50% of the maximum brightness. For example, a 30-degree beam angle implies that the intensity of the light would drop to 50% of its maximum brightness at a 30-degree spread of light.

Secondly, the impact of different beam angles on underwater lighting:

1. If the beam angle is relatively small (for instance, 5-13 degrees), it is more suited for long-distance illumination, providing a clear illumination for distant targets whilst forming a small, focused point of light up close. In clear water, this type of dive light can have a maximum illumination distance of up to about 200 meters.
2. If the beam angle is relatively large (for instance, 60-120 degrees), it is more suited for close-range wide-angle illumination, ideal for illuminating a large area at close distances, such as for photography or observing the surrounding environment during a dive. In clear water, this type of dive light can illuminate an area with a diameter of about 10-20 meters.

Thirdly, how to choose the beam angle:

1. Cave diving or deep-water diving: As there is a need for as much distant visibility as possible, a dive light with a smaller beam angle of about 5-13 degrees is recommended. In comparison, a dive light with a larger beam angle (such as 75 degrees) might only be able to illuminate up to about 30 meters in these conditions.
2. Underwater photography: If the primary purpose of the dive is photography or videography, then using a dive light with a larger beam angle such as 90 degrees or larger is recommended. This ensures maximum and evenly spread illumination coverage during shooting, resulting in optimal lighting effects for the whole picture.
3. Recreational diving: If you’re a recreational diver and have no specific lighting needs, a dive light with a beam angle of about 20-45 degrees will suffice. This type of light provides a sufficient illumination range, and its lighting distance can meet the needs of everyday diving.

In conclusion, choosing the right beam angle for your dive light can significantly enhance the quality of your dive. Every dive should take into consideration the specific dive environment, purpose, and personal preference to choose the most suitable dive light, rather than simply pursuing the one with the most powerful lighting or maximum illumination range. This way, you not only meet your lighting needs but also ensure the longevity of your dive light and the safety of your dive.