Sea & Sea fisheye, compact, acrylic and glass dome port review

In this review I tested 3 Sea and Sea dome ports with my Nikon D300 and Tokina 10-17mm lens in the swimming pool, checking sharpness, color and contrast.

Sea & Sea Compact dome port

The S&S compact dome port is a light-weight, 6 inch acrylic dome port. Total width is 6.5 inches including the outer plastic. 1lb 9oz with the cover and 20mm extension ring. $500 in the USA. The SX extension ring (20mm) is an additional $190.

Sea & Sea glass dome port

The S&S glass dome port is a compact 6 1/2 inch dome port made by Athena for Sea & Sea. 2lb 12oz with the cover and 20mm extension ring. $1250 in the USA. 

Sea & Sea Fisheye dome port

The S&S fisheye dome port is a 8 inch acrylic dome port. Total width is 9.5 inches including the outer plastic. 2lb 9.7oz with the cover. $650 in the USA.

Dome port test methodology

I took hundreds of test shots, at focal lengths of 10mm, 14mm, and 17mm. I took shots at distances of 2ft and 4ft away. I also compared center areas, side areas, and corners of the photos. I took photos at apertures F5.6, F8, F11. I also had two experienced photographers independently compare 100% crops of the test photos.

Glass and Acrylic dome port test results 

• No difference between glass and compact dome ports

• No difference between dome ports in center sharpness

• All dome ports sharp in the center

• All dome ports sharpest in the corners at F11, and usually fairly sharp at F8, and not too bad at F5.6

• Large fisheye dome port (acrylic) was best of them all, but only by a small amount in the corners, if you look at 100% crops.

Dome port test conclusions 

• Compact dome port (acrylic) is best for close-focus wide angle (CFWA) shots, and for travel, and easiest on the pocketbook.

• Fisheye dome port is slightly better in the corners at F5.6 and F8.

• No need to spend the extra money on the glass dome port.

• When using the Tokina 10-17mm fisheye lens, the fisheye dome port does not need the 20mm extension ring, but may benefit from it? (This will be my next test). Rotating the aperture dial is more difficult without the ring on.

• The compact dome port definitely benefits from the 20mm extension ring.

• The fisheye dome port will give better results for over and under shots.

• Glass ports are heavier, more resistant to scratching, and shed water easier that acrylic ports. It's possible that other well-made large glass dome ports have optical advantages over acrylic ports (e.g. - Subal or Seacam ports), but I didn't find any with this particular port.

Disclaimer - these test results may not apply to other manufacturers of dome ports, or in the conditions you shoot in, you should always do your own port tests. Dome ports can vary in quality. 

Further Reading

Dome port optics and the virtual image

CFWA - shooting close focus wide angle underwater

Best lenses for underwater photography

Fisheye lenses versus wide angle lenses

Sea & Sea MDX-D300 underwater housing review