I just picked up the extension ring 40 and NX fisheye dome port for my MDX-D300. The extension ring locks onto the housing nicely with the port lock, but when I twist on the dome, it seems like there is no is way to lock it into place, since the port lock is being used for the extension ring? Not that I intend to go unscrew the dome underwater, but it doesn't seem like it would take much at all to twist it off a bit since its completely insecure. Have I done something wrong here or is this normal?
Thanks.
Yeah you are doing it all right... it is just like that.
I did this shot with a "half twisted dome" over an SX Extension Ring and a Sigma 8mm/4 Circular fisheye to add some drama:
Good Luck!!!
Hey Todd, I have the same housing, extension, and port. This is a common problem with many differant manufacturers. Why they don't put some type of lock on the extension ring is beyond me. Make sure the port is completely on when entering the water, once you start to descend the pressure seems to secure it better. I haven't had any problems so far.
Mike
Unfortunately, its an issue with all of the manufacturers housings.
Thanks, guys. Reassuring to hear, but seems weird.. I imagine they don't build the port lock into the housing for the fun of it, but instead for a reason. So, why the same reason doesn't merrit a lock on the extension ring is bewildering. Oh well, thanks again.
