Before every trip I ask myself which lenses and ports I should bring along. And once at our destination, the question then becomes which lenses need diopters, extension tubes, and what ports are best with those lenses. The following article documents my experience with the lens and port combinations I've tried. In some cases, I also include notes on camera settings and substrobe arm lengths. These notes are as much for myself as anyone else, since I will use this article as a reference on future trips. You can expect this information to be updated once in a while as I try new lens / port combinations and fine-tune old ones. If you have additional information and/or opinions on these or other lens and port combinations, please share them in the comment form at the end of this document.

Canon EF-S 10-22mm f3.5-4.5 with #5503.50 Dome Port

The 10-22mm lens vignettes at 10mm when used with Ikelite's #5503.50 port. There is severe loss of definition on the left and right sides when the lens is zoomed at 22mm. It's preferable to avoid this lens and port combination if you can.

Canon EF-S 10-22mm f3.5-4.5 with #5510.80 Dome Port

I wouldn't imagine having this lens or port without the other. The corners have a slight stretched look with some loss of sharpness. The port provides plenty of lift, and when used with two 12" ULCS buoyant arms or one 16" ULCS buoyant arm plus one 12" ULCS standard arm, the system is slightly negative. The port adapter appears to have been milled a little smaller than most other Ikelite ports. It slides in the port opening very easily and remains a little loose. I would not trust this combination for aggressive shore entries with large waves and surge.

Ikelite sold this dome port without a port shade. You'll have to find an authorized Aquatica dealer to buy the port shade seperately. I find the port shade cuts down on lens flares and also protects the port from accidental damage. The port shade does add a little weight though.

Canon EF 17-40mm f4.0 with #5503.50 Dome Port

Canon's 17-40mm f4L has been known for it's quality on film cameras, but I've found it a little soft and lacking in contrast on my 20D. When used with the #5503.50 dome port, sharpness in the center of the image is acceptable but the edges, especially the corners, are rather soft.

Canon EF 17-40mm f4.0 with #5510.80 Dome Port

General sharpness and edge detail is better with this port than the smaller #5503.50 dome port, but the corners are still somewhat soft, with slight stretching/distortion evident. Image quality improved somewhat at 29mm. Good pictures can still be taken with this lens and port (some cropping will be necessary), but I would suggest using the EF-S 10-22mm lens instead. We currently own one 10-22mm lens, and since Melanie prefers WA photography, I usually get the 17-40mm. I plan on buying a second 10-22mm lens, or an equivalent fixed focal length lens, before our next trip.

Canon EF-S 17-85mm f4-5.6 with #5503.90 Dome Port

I wasn't expecting much from this combination since the 17-85mm changes lengths significantly as it zooms in and out. The wide-angle shots are sharp and edge detail is pretty good at 17mm. As you zoom in (22mm for example), the edges get much softer. At 85mm (136mm equiv.), sharpness and edge detail are once again very acceptable.

Canon EF 28mm f1.8 with #5503 Dome Port

I used this lens / port for 1 1/2 days before having to switch for a night dive. I would have liked to play with it some more. The results are sharp edge to edge, and have only a slight wide-angle feel. I definately like the results. This lens is great for small-medium sized coral and medium-large sized fish. You'll have to get fairly close to some fish to fill the frame, so some skill is required.

We had the chance to dive with a friendly turtle for 25 mins. I had the 50mm, which was too much for the close passes I got with the turtle. The 28mm would have been perfect for this kind of interaction. If you plan on getting close to medium-large sized fish (up to turtle size), this is the lens I would choose.

Canon EF 28-105mm f3.5-4.5 with #5503.55 Dome Port

While I had the 100mm Macro lens with a flat port on my housing, Melanie was to use the 28-105mm lens with a dome port on hers for close-ups. The 28-105mm was not supposed to need a +4 diopter according to Ikelite's website. This is true above water, but not underwater. I left my 58mm +4 diopter at home, so we couldn't test this lens / port combination.

Canon EF 50mm f1.4 with #5503 Dome Port

The 50mm f1.4 lens provided excellent results using Canon's 12mm extension tube and Ikelite's #5503 dome port. The extension tube moves the nodal point outwards a little and appears to match up with this dome port very well. An extension tube also does not reduce image quality as an add-on diopter filter would. This lens and port combination is best for medium to large sized fish.

I was using this lens and port combination when we encountered a medium-sized hawksbill turtle in Bonaire. We swam with the turtle for 25 mins as it explored the shallows. On three occasions I placed myself in it's path, and it came up and around me as I took pictures. When I had a good composition, the turtle was a little far for the flashes. When it was close enough for the flashes, it filled too much of the frame. For this kind of encounter, I would definately suggest using a wider lens (the 28mm or 10-22mm lenses for example).

Canon EF 85mm f1.8 with #5502 Flat Port

The diameter of the 85mm lens does not allow a focus ring to be used, so you'll have to rely on the camera's Auto Focus exclusively. Our prefered camera settings were AI Servo AF with center-weighted metering, 1/125th shutter speed, and Manual or Shutter Priority.

The +2 diopter filter provides a good range of focus, allowing us to get close enough for most small critters and far enough for medium sized fish. We also tried a +4 diopter filter, EF12 II extenstion tube, and EF25 II extension tube - all of these offered a limited (in some case very limited) range of focus.

The Canon EF 100mm Macro lens with a flat port has an extended focus range - you can get a little closer, and focus from much farther away for those very shy critters. The quality from the 100mm lens is also a little sharper. I would suggest using the 100mm Macro lens instead of the 85mm.

Canon EF 85mm f1.8 with #5503.50 Dome Port

The 85mm lens and dome port combination does not allow you to get as close to your subject as the flat port does. The closest you can get is about 3-4 feet before the camera is unable to focus. This combination may be good for shy, medium sized fish. Fish smaller than 1" will be too small in the photo, and larger fish like groupers are too large to fit the frame. There are other lens and port combinations that have a much broader focus range, like the Canon EF 100mm Macro lens with a flat port.

Canon EF 100mm f2.8 Macro with #5508.45 Flat Focus Port

The 100mm Macro lens hits the flat port under compression, but this isn't really a problem since it has a fixed length when focusing. You'll have to remove any UV filter you may have on it though. A manual focus knob has been added directly to the port since the lens diameter is too large for the standard Ikelite focus rings. The focus knob is fairly easy to use and comes in handy when the lens is set to 0.31m minimum focus distance. The Canon 20D AI Servo mode is very useful and definately recommended. Expect to use a good modeling light (output strength and diffuse light) to get the best out of the Auto Focus at night. This lens and port combination, with dual substrobes and short substrobe-arms, is very negative. Additional buoyancy compensation (cork, high density foam, dry boxes, etc.) is almost a must. You'll find that I've used two Trident D652 Large Black Drytubes to provide the necessary byoyancy. In the future, I may use PVC tubes (glued closed at both ends) with ULCS AC-Tosh flashlight holders to provider a cleaner and more flexible solution.

If you set the lens to 0.31m minimum focus distance, expect to take some extreme macros, but at the cost of a finicky focus. Generally use this mode if you know beforehand that most or all your subjects wil be very small (tiny shrimps, coral polyps, etc.). If the camera is having problems focusing, you can use the manual focus knob to get the lens "close enough" and then let the Auto Focus take over. Another alternative is to leave the lens in AF, but map the camera's Auto Focus function to the * button. This way you can focus manually, but when necessary, use the * button to have the camera focus for you.

The 0.48m minimum focus distance setting on the lens is excellent for all but the smalles critters. In daylight, the Auto Focus in this mode is fast and accurate. At night, you'll need a good modeling light.