I was looking at getting this lens to use in Fiji on the Beqa Lagoon shark dive. It would be used with an AOI 8” dome on an Olympus E-M10 Mark IV. One of my main concerns though is that looking at older reviews on the lens there were numerous comments about purple blobs appearing in shots. This apparently was common when this lens was used on Olympus bodies. I saw in one article though that this issue had been corrected in new Olympus bodies. Is anyone using this lens and having the problem? Is it even worth getting or should I just go the Oly 9-18 route?