Ewa-Marine AV110 Autofocus Adapter

The AV110 was developed for the use of auto-focus lenses in the U-A series of Ewa-Marine housings. The function of the AV110 is to ensure a fixed and rigid connection of the housing's front port to the tripod thread under the camera's body. This allows the auto-focus to lengthen or shorten the effective length of the lens without being affected by the surrounding water. Without the AV110 the lens's motor would have to "pump" air from the rear of the housing to the front, and vice versa, during focusing. This definitely exceeds the design specifications of the motor and could lead to damages of the lens's mechanics.

Always assemble the AV110 in such a way, that the center of the cameras lens is directly in the center of the front ring. To achieve this, use different spacer combinations to achieve the desired result.

Always check, that there is enough space between the lens and the front port when assembled. This will be necessary to allow the auto-focus to operate the lens without it actually touching the front port. The distance between the lens and the front port should be, depending on the lens, between 5mm and 20mm (0.2 and 0.8 inches).