Has anyone used these? https://www.reikanfocal.com are they worth the money? is it better to send the lens off to an approved service agent? One of my lens took a bit of a knock, recently, and it seems that its not as sharp as it used to be. (but then could that be my imagination? ) Rather than use the "Pyramid" as I'm not sure I'd trust myself TBH, I thought that if it truly is fully auto, then its gotta be worth 40 quid? ( or 70 quid depending) Any downsides to it?