The Spectrum Filter SF -4 B WWL-1 is designed for the Nauticam WWL-1 wet lens and compensates for the light absorption of blue water. therefore provides a smooth, well balanced light spectrum to the sensor of your camera. This greatly improves the color rendering of your images and adjust the color coordinates close to daylight for outstanding results with manual white balance.
The Spectrum Filter SF -4 B WWL-1 has a compensation depth of 8m. At this depth the filter makes a pertfect compensation of the light absorption of the water column. The camera then sees a daylight spectrum just like shooting at the surface.
The filter works best for blue water within a depth range of 6 to 20 meters. The filter has a damping equivalent to a loss of 4 stops. Normally low noise cameras that allow to shoot at ISO 1600 or higher are requried when using this filter.
IMPORTANT: If you experience problems wit too low light level switch to a lighter filter such as the SF -2 WWL-1 (loss equvalent to 2 stops). The use of a lighter filter is always the better option than using no filter at all!