I have the Subal 105 VR port with manual adjuster knob (for use with the new Nikon 105 VR lens). The port comes with some instructions which I pretty much followed to the letter but here are some brief observations.
- It turns the opposite way to the 60mm flat port!
- It uses a slightly thicker oring, be very careful not to mix up your orings. I keep all mine in little resealable sandwich bags with the port size written on the front.
- You have to attach the lens after the camera is in the housing (because the lens is too fat to fit through the back way). I keep the camera body cap handy so I don’t get any stray dust in my camera whilst I’m fiddling with my housing before I fit the lens.
- Make sure the lens itself is switched to M/A unless you want to manual focus for the whole dive! As you put the port on its easy to knock that little switch so care is needed.