Disassembly – 7Artisans 35mm F2.0 lens aperture ring

It’s short partial disassembly of 7Artisans 35mm F2.0 full frame lens – aperture ring area. Surprisingly 7Artisans made this lens with click-stop aperture mechnics, so I was curious to check the implementation.

Right after removing mount ring I noticed aperture transmission ring similar to one in 7Artisans 35mm F1.2 APS-C lens. It is connecting movement of external aperture ring to the internal aperture lever.

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You have to remove transmission ring first, then accurately take off aperture ring – watch out the small metal ball and spring, it’s easy to miss them.

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It is interesting to see that grooves for every aperture full stop are long – that explains more snappy clicks and more stable aperture ring position comparing to custom MODs of 7Artisans 35mm F1.2 and Mitakon 35mm F0.95 II . Half-cylindrical shape of that grooves are perfectly matching ball curvature.

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Hole positioned right near the center of DOF scale. I’ve added red dot on lens scale for better visibility. When you disassemble ring, simply catch the ball in that area. Spring has much smaller diameter than the hole, but the ball size is properly matching.

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After this 7Artisans 35mm F2.0 lens disassembly I decided to update my Mitakon 35mm F0.95 II aperture ring in the same way. So basically at each position of aperture stop I made similar cylindrical grooves like on 7Artisans 35mm F2.0, but slightly deeper because diameter of Mitakon lens ring is larger. After modification lens aperture ring of Mitakon 35mm F0.95 II lens become much more snappy. It’s also much more easy to make horizontal grooves using electrical drill comparing to orthogonal hand drilling of round holes. Another positive side is that these grooves are more tolerant to ball position.

 

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