X-shooter yukosteel was brave enough to clean some dust spots inside his XF50-140… by dissembling the rear element. He says it was an “interesting activity” and shared his experience and some pictures of the naked XF50-140mm rear area at the FXF.
And it turns out he’s not the only one. X-shooter Fiddlergene disassembled his XF16-55mmF2.8. However, after he cleaned it up, he used one less screw to re-assemble it.
Check out more in this thread.