Just picked up a nice set of PolarPro filters on eBay (thanks, @PingSpike!) but have discovered they are an older version of the Cinema series. They have ridges around the bezel whereas current versions are smooth. According to PolarPro they changed the design after some early reports of gimbal calibration interference but claim this only happened in a few cases.
Does anyone have the older version (with ridges) and have you encountered any problems with them? It would be useful to know before I start mounting them on my Mavic.
Hmmm…
Sorry, I wasn’t aware of that when I posted my findings 
So if you fit the filter then power on the drone you think it may fail the calibration checks?
At the worst, that’s all it would do - no damage would be caused would it?
You could always flip the two packs on eBay (separately) for a profit 
Absolutely no apologies necessary. I’ve still ended up with a set of six high-quality ND filters in excellent condition and at a great price!
Having read through PolarPro’s site they seem to be genuinely concerned about building quality products and only changed the design after receiving ‘a few’ complaints. This indicates that most people seemed to fly with them safely and I have noticed them appearing in quite a few YT videos.
I’ve emailed PolarPro to see what they have to say on the matter.
I meant to ask, what was the outcome of this one @Londroner?
Did you try the filters out??