The world of IKEs, PENs & OMDs
In the ever-expanding market of camera lenses, housings, and ports, it has become increasingly difficult for the beginning UW photographer to choose the right underwater system. New technologies also bring better ergonomics, lenses, and more megapixels which easily will make the older system look awkward and obsolete. There are limiting factors that will make the choice easier. Like your budget of course. And the more experienced photographer often has developed a specific interest, like shooting macro or wide-angle subjects. Or choosing a cropped sensor instead of a full-frame sensor which will automatically limit the spectrum of lenses and housings. Then there is also the type of strobe to select, and the system to fire the strobes, electrical cables of fiber optics, in which case there is a choice between either an internal flash or LED trigger to ignite the optical system.
For strobes and lenses, the underwater market seems to change less rapidly. The choice of the lens is crucial for the quality of your pictures, perhaps much more important than the number of megapixels of the camera, or even the size of the sensor. A superb lens will stay with you for many years, at least when the housings designers are so kind as to provide the suitable adapter and port for your favorite top lens
For about 20 years I have been a faithful user of the Ikelite DSLR and Olympus PEN systems, with the Oly combo as a back up during my diving trips. The cameras (Nikon DX and E-PL5) equipped with fisheye lenses: the legendary Tokina 10-17 and Panasonic 8 mm fisheyes (which I later changed for the Oly 8mm with a 2 cm extension), respectively. With Precision mini domes (5 and 4 inches), allowing to get very close to the UW object. But recently I followed the urge to try something (a bit) different and more simple and switched to the PT-EP14 housing with the newer Olympus M1 Mark II camera inside. But I kept the Oly fish-eye and 4-inch dome (see insert), which so far seems to work well on the OMD housing with a PEN/OMD adapter. Like the older PEN housings, the PT-EP14 depends on a small internal flash to trigger the optical cables and strobes. In my case, that would be the Ikelite DS 161 strobes with optical adapters. No LED trigger is yet available for the OLY housings, but this should not be much of an issue since the flash set to lower (1/64) power will not easily drain the batteries. I do no regret missing TTL, since I have always been happy with shooting in the Manual mode with the Ike strobes, even when triggered by the electrical cables of the DSLR housing. I am now on the look for a Tokina 10-17 equivalent on the 4/3 market. Perhaps the Panasonic 7-14 or Olympus 7-14, which seem to have excellent records. And eagerly waiting for the return of diving days, to see how this will work in the real world of the Oceans.