[stillshot2]

My DAL lenses seem to all have this tombstone-looking gold plated contact on them as pointed out with a red arrow in the link below, and it is easily getting noticeably scratched up on multiple lenses with the gold plating wearing off. I've never had this problem with any of my 3 Sony lenses or 3 Minolta Maxxum lenses I used to own, but is this normal for Pentax equipment? I also hold down the lens release button while taking a lens on and off so the screw drive can't rub against the mount. Anyone know why it's still getting worn, and perhaps what this contact even does? I notice it isn't even on older Pentax lenses, so I hope it's not too important. I also hope nothing is shaving off and getting into the mirror box. Let me know your thoughts. Thanks

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[Ole]

This is to provide ground connection for the electrical circuit in the lens. You only find it on lenses with a plastic mount. Metal mounts provide plenty of ground contact by being made of metal and don't need this contact.

[stillshot2]

Ok, that makes a lot of sense, as well as why it is getting scraped up; it has to make firm contact with the mount in order to ground the lens.