Auto Chinon 135mm f2.8 PK mount problem on K-30

Flavius · 01-07-2020, 07:55 AM

Hello,
I'm new to Pentax and photography so it might be a silly thread but I need help.

I have a great K-30 and a nice manual lens Auto Chinon 135 mm f2.8. My problem is that every time I use this lens stopped down from 2.8, no matter where, the mirror starts to flip.
When I take pictures at f2.8 there is no problem, but on every other step, the window starts to flip after every shoot, once or twice.

Please help, thank you!

**Just1MoreDave** · 01-07-2020, 12:20 PM - **1 Like**

Is the mount on this lens black? The K-30 really wants a mount that conducts electricity, like the typical silver or chrome mounts on most lenses. A handful of older lenses have black anodized aluminum. You can scrape or sand the black coating off in the area where the electrical contacts are on the camera's mount. Then the lens will work better.

That's the only guess I have at the moment.

Flavius · 01-07-2020, 11:26 PM

The lens mount is silver and clean. Thank you for the answer.

01-07-2020, 07:55 AM	#1
Flavius New Member Join Date: Dec 2019 Photos: Gallery Posts: 7	Auto Chinon 135mm f2.8 PK mount problem on K-30 Hello, I'm new to Pentax and photography so it might be a silly thread but I need help. I have a great K-30 and a nice manual lens Auto Chinon 135 mm f2.8. My problem is that every time I use this lens stopped down from 2.8, no matter where, the mirror starts to flip. When I take pictures at f2.8 there is no problem, but on every other step, the window starts to flip after every shoot, once or twice. Please help, thank you!

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01-07-2020, 12:20 PM - 1 Like	#2
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	Is the mount on this lens black? The K-30 really wants a mount that conducts electricity, like the typical silver or chrome mounts on most lenses. A handful of older lenses have black anodized aluminum. You can scrape or sand the black coating off in the area where the electrical contacts are on the camera's mount. Then the lens will work better. That's the only guess I have at the moment.

01-07-2020, 11:26 PM	#3
Flavius New Member Join Date: Dec 2019 Photos: Gallery Posts: 7 Original Poster	The lens mount is silver and clean. Thank you for the answer.