I recently purchased the NiSi JetMag Pro magnetic filter set in the 82mm size. I am having an issue in that it doesn't seem to screw on properly to my Sony 16-35mm GM lens, which has an 82mm filter thread. It does "sort of" screw on, but will only go about half a turn before getting stuck. There is a lot of resistance when turning. I have not had this issue with any other filter on this lens. It almost feels like the pitch of the threads on the filter base is off. Has anyone experienced this? Has anyone used this kit with the particular lens? Strange...
I'm not sure, but at some larger sizes, there is a "coarse" and a "fine" thread standard. Is it possible this occurs on this lens? I have a lens that does have this happening (an older Hasselblad lens) and the wrong thread will actually screw on more-or less OK... it depends on how tight the threads have been machined to the dimensions of the thread diameter basically, and I somewhat suspect that some companies go a bit loose on the thread size where there is the dual standard issue to allow them to work even though they aren't really supposed to.
I had thought this "coarse" and "fine" threading started occurring at 86mm and larger, though, so it's possible that this isn't what is causing this, but just poor manufacturing.
I don't have this lens, but I do have the filter kit and I've not had any problems on my lenses (one of which is an 82mm filter thread).
Bummer. After close inspection to rule out galled threads on your lens, send it back for a replacement. Quality control is pretty scarce these days when dealing with companies who don't hold their reputation above their profits.
I only have one 82mm lens (Samyang 135/1.8) and the NiSi Jet Mag Pro ring screws in perfectly...It would suck to send the NiSi back for a replacement and find out that your 16-35 has the borked threads....
I suggest you try to thread the NiSi filter on to the front of another filter, if you cross thread the filter it's way less damaging than cross threading the lenses threads. Inspect the threads of both the male and female surfaces, maybe something lodged in one of the grooves. Additionally, threads often cause resistance due to metal to metal contact, graphite will lube the threads making for less resistance.
Thanks all for the replies. I have done some more investigating and think I have discovered the source of the problem. The NiSi base was not mating well with my lens, but all my other 82mm filters don't have an issue when mated to either the lens or each other.
The issue was not with the threads themselves. The filter base was slightly out of round and that was the cause of the binding I experienced. I was hesitant to force it on for fear of messing up the threads on a $3K lens. It does go on now, but there is still a noticeable friction point after about 90° of rotation.
Not sure how this came to be. The parts are shipped in a hard case, so handling during shipping shouldn't be a thing and it was like this from the first time I unpacked it...
