Summary: makes the G 10 more durable and easier to handle while protecting the lens. A must for using filters. You must remember to remove the front half of adapter when using at the camera at wide angle.
Summary: This adapter makes it nearly impossible to use a polarizer with a G10. With both pieces a 58mm polarizer vignettes badly. The two piece design uses a proprietary 57mm thread in the middle, so you can't attach it there. kind of frustrating. They really needed to make the front threads much larger, either 72 or 77mm. BAD design. So It's only use is for a teleconverter. If you want it for filters don't waste your money, but the one from lensmate.
Summary: Unfortunately I read unfavorable reviews from other sources after I purchased the lens adapter and decided to return this item and the two filters I purchased with it. Two issues...the canon lens adapter is two pieces of plastic with plastic tabs that affix to the camera that I felt would easily break, second and most of all the reviews indicated that the fully extended lens hits certain filters attached to the adapter and causes vignetting....poor design.
Summary: I use the adapter for filters and protecting the lens. The adapter comes in two pieces (screws together) You have to take it apart to use it with wide angle it vignetts. Not convient when going from wide to tele.