Please note: I started writing this article shortly after returning from Bonaire in June, but have not had a chance to complete it yet. Hopefully this draft version will be useful for those of you currently looking at buying Ike's new 8" dome port. I expect to have this article completed (with example photos) within the next few weeks.

A Little Background Info...

To truly appreciate the current 8" port design, it's necessary to talk about it's predecessor...

Over a year ago, Ikelite purchased four hundred 8" ports from Aquatica, and packaged them with custom delrin adapters. I bought two of these 8" dome ports #5510.80 for our Ikelite Canon 20D housings. I also bought some Aquatica WA port shades to minimize lens flare, and to protect the port from accidental contact with rocks / coral during entry.

I noticed that the delrin adapter sat a little looser in the port opening than Ikelite's regular ports. Brett from Ikelite explained that since the adapters were machined, they were truer than Ikelite's other molded ports, so this was in fact normal. Still, with the added weight of the WA port shade, I decided to be extra careful during entry not to bump the port -- just in case. A few months ago one of our housings flooded. The port seal failed completely as I put the housing in the water. The port and o-ring were installed properly, and the housing had already been on one dive that day. I expect several factors were at work to break the port seal, including strong surge, waves, the buoyant nature of the port, and the two port clips (that allow the port to wobble on a single axis within the port opening).

Ikelite's New 8" Port #5510.40

The new port is sold by itself, or packaged with one of three different stalk lengths. The older Aquatica port used an alluminium back with a delrin adapter. The new Ikelite port uses a single delrin back that incorporates the threads necessary to connect the various stalk lengths. The delrin back protrudes into the port quite a bit, making it impossible to clean the very edges of the port. This isn't critical since the edges do not intrude in a WA lens' FOV, but over time, the edges could trap lint and debri that might break free after the port is installed. For those of you used to the Auqatica port, you'll find the new Ikelite port is also a little less buoyant.

Port Clips

When buying the port in combination with the shortest stalk length #5510.82, Ikelite also includes a set of replacement port clips #9072.24. They protrude less, and on both our housings, also held the port tighter than the older model. In my opinion, anyone using an 8" port on an Ikelite housing should get themselves a set of these new clips - no matter which stalk length you're using.

Stalk and Lens Combinations

Ikelite provides three different stalk lengths for their new 8" port:

• The short length #5510.10 for extreme wide-angle lenses like the Sigma 15mm Fisheye.
• The medium length #5510.16 for regular wide-angle like the Canon EF-S 10-22mm.
• And the longest #5510.24 stalk for longer zoom lenses.

The stalks fit nice and tight into the housing's port opening, but the stalk-to-dome threads can be a little difficult to start -- and take some effort to screw in.

The following list summarizes our experience with various combinations of lenses and stalk lengths. Keep in mind that our impressions are based on using Canon 20Ds with a 1.6x crop factor. The results would certainly be different using a full frame camera.

Canon EF-S 10-22mm with #5510.16 Stalk

To be continued...

Sigma EX 15mm Fisheye with #5510.10 Stalk

Sharpness is maintained throughout the image. This lens and port combination is a very good match. The lens itself provides a good wide-angle FOV with the Canon 20D. The fish-eye effect is fairly subtle and can be used to good effect. A highly recommended combination.

On a related note, if you use this lens in AF, you should not install Ikelite's focus gear. The lens barrel rotates when auto-focussing, and the gears will prevent the lens from functioning properly. You'll have to either set the lens to manual focus and use the focus gear, or set it to auto-focus without the focus gear; switching back-and-forth from manual to auto-focus by using the "*" key will not be possible with this lens.

Canon EF 28mm f1.8 with #5510.10 Stalk

Very sharp, corner to corner. This focal length can be a little difficult to use since it's between wide-angle and a medium focal length on a Canon 20D. The results are worth the trouble though. Contrast and sharpness are very good. My prefered subject with this lens are small coral heads and medium-large fish. Expect to include context / surrounding corals when taking fish shots.

Canon EF 50mm f1.4 with 12mm Extension Tube and #5510.10 Stalk

The 50mm lens needs a close-up diopter or extension tube to focus properly. The range of focus when using a 12mm lens extension tube is very limited -- only a few feet at it's farthest. I would not recommend this lens and port combination. The 50mm lens (with the 12mm extension tube) is much better suited to the smaller #5503.50 dome port, where range of focus isn't a problem, or use it without an extensution tube with a flat port.

Port Shades

Unfortunately, Ikelite does not currently provide port shades for their new 8" dome port. Ike said that he is looking at possible materials to make some, so port shades may be available in the future.

Not only do port shades help prevent lens flares and reflections within the port, but they also protect the port surface from scratches. Just recently, one of Melanie's strobe arms fell on the port when exiting a shore dive. Luckily I have some Novus 1-2-3 scratch remover on hand, so I'll be able to address the problem. Had there been a port shade installed, it would have taken the hit, not the port itself.

Conclusion

Although a little difficult to clean around the inside edges, this new 8" port is an improvement over the earlier Aquatica port. The build and optical qualities of the port are excellent. The stalks make using different physical length lenses possible, although changing the stalks is a little bit of a hassle because of the tight tolerances on the threads. Overall, I would only invest in Ikelite's smaller dome ports for the Canon EF 50mm f1.4.