I've stumbled upon a problem with the Inon MRS magnetic rotation system ports which is incredibly annoying. If you are using this system for underwater photography, or might want to use this system in the future, read on.
The port system facilitates manual focus by using a magnetic collar on the outside of the port and magnets that you attach to the focus ring of your lens inside the port. When you rotate the external collar, the magnetic attraction between the external collar and the internal magnets on your lens rotate the lens, allowing you to focus manually just like you do on land. Ingenius.
The system has been around for some time, and as far as I know, the port system currently only works with Inon housings, Olympus housings, and some other housings if you use adapters (like my Zillion housings).
The problem with the system is that it's designed to fail.
The magnets on the external collar are attracted to the metal of the lens port, meaning that there is constant pull on the magnets embedded in the collar. So over time, this magnetic attraction literally pulls the embedded magnets out of the collar, resulting in penetration of the internal surface coating of the focus ring, and causing the collar to freeze up. The magnets literally punch holes on the inside surface of the collar.
When my focus system froze up on me earlier this year while I was in Lembeh, I only figured this design flaw out by forcefully disassembling the port system and sandpapering down the inside surface to get rid of the bulges created by the exploding magnets.
This emergency equipment surgery meant that the system worked for the duration of my stay, but of course, a few weeks later, the same thing happened again.
Once I got back, I sent the port to Inon HQ for a look, and was informed that it would cost me something like US$85 to repair the focus ring. The thing is, the way the system is designed, this problem will occur with every single MRS port Inon makes and sells. Inon acknowledged as much.
So, basically Inon has been making and selling a faulty design, knowing that it's faulty and more than happy to charge for repairing the fault, which will fail again, and again, and again...
Inon HQ advised that it's best to remove the focus ring from the port when not in use. Makes sense. Only thing is, Inon ships the ports with the focus ring attached (meaning the magnetic degeneration process already underway once the port is assembled by Inon), and every retailer keeps the rings attached (meaning that the problem is exacerbated by just having the port on display or in stock).
If best practice is to keep the ring off the port, why does Inon ship the port with the ring attached?
I did a quick inspection of several ports at a friend's shop in Japan. Sure enough, even new on the shelf, the focus collars on the Inon ports had baby bulges from the magnets...virtually assuring product failure.
So...I'm being forced to put up US$85 to fix Inon's faulty design for which they will neither take responsibility nor undertake steps to eliminate the problem.
Guess who's no longer using Inon gear?