They returned amazing photos but had some crazy issues. The lens cap didn't pop off on at least one of the cameras for Venera 9-12 (yep, all four). The Venera 14 lens cap popped off but landed under the surface tester arm meaning they could test the lens cap just fine but Venus, not so much.
Imagine sending a probe to another planet, land successfully, and survive the hostile environment (for a little while anyway), only to have the issues with the lens cap. Again, and again, and again, and again.
Imagine sending a probe to another planet, land successfully, and survive the hostile environment (for a little while anyway), only to have the issues with the lens cap. Again, and again, and again, and again.