So I'm trying to clean my sel18-200 because I have an accumulation of dust inside the front element due to frequent zooming (intake of air). There's a noticeable build up near the center of the element.
I've been trying to remove the front element to no avail. I even went about ordering a special rubber tool :
Unfortunately, attempting to unscrew the front retainer ring has been quite the issue. It won't seem to budge. I was curious if anyone else here has had any experience cleaning their 18200