The Olympus 100-400mm IS lens size is 72mm, please reconfirm the number mark as "ø" (diameter) symbol, if the number is 72, just need to order same 72mm size filter ,thanks. 

50 mm Yongnuo lens filter size is 58mm, you can reconfirm your lens mark as "ø" (diameter) symbol, if the number is 58mm, it would be ok ,thanks. 

If you rotate your ND filter past the ‘Max’ mark on the filter rim, it can cause an x-pattern, so ensure you’re not over-rotating. Variable ND filters also have limited application with wide angle lenses (they can only be used to about the halfway mark of Min and Max markings because the field of view is so broad). For a wide-angle lens, we suggest using fixed ND filters or ND2-32 or ND8-128. You can also try adjusting your focal length and reducing the density (rotating back towards the ‘Min’ mark) until the colour shift disappears. 

Unfortunately this is for adapting lenses to Olympus' modern digital Micro 4/3 cameras. It won't work with the Pen FT or similar half-frame film cameras, and you most likely won't find anyone making adapters for these. 

Will work with any camera that has the thread for a Tripod mount. As far as I know yes will work with the Sony as it as a Tripod thread.