Sea & Sea Extension Ring 46 with Focus Knob for Wide-Angle Lenses in MDX Housings

Using the Extension Ring 46 with Focus Knob from Sea & Sea, you can operate manual focus with select Canon and Nikon wide-angle zoom lenses in ports on MDX series underwater camera housings. Check out the list below and see Canon MDX System Chart or Nikon MDX System Chart. A compatible FC focus gear is required for manual focusing, and can be used in conjunction with a zoom gear. This represents a significant improvement to the Sea & Sea product line, which previously only allowed for the use of auto focus with zoom gears.

The focus knob on the ring is located in a convenient position that makes it easily accessible via the index finger and thumb. Additionally, the extension ring is equipped with a port lock. An optional left grip extension lets you position the left housing grip forward to provide easier access to the extension ring's focus knob.