Open Sonnar

The 3D Printable Lens Focusing Mechanism


Creative Commons Attribution Noncommercial Share Alike

Commercial use is not allowed, you must attribute the creator, you may remix this work and the remixed work should be made available under this license.

Learn more or download attribution tags


One of the most beautiful features of digital fabrication is the way it allows us to salvage the past. Our reality may be the life's work of millions of brilliant people, but often, time and technology relegate their astonishingly functional artifacts to mere novelties or footnotes. Sometimes, though, for a low cost and a modest amount of design time, 3D printing enables us to rip their work into the present, to compete with modern day on it's own merits.  I only know a small amount about photography, but I am beginning to suspect that the 80 year old lens in the photos above  - the *Carl Zeiss Sonnar 50mm 1:1.5* - is one of these objects worth reviving.  
The lens was made in the early 1930's, from robust metal and optically flawless glass in a *Sonnar* arrangement  - a designation describing the number and placement of glass elements that focus the light, and also an arrangement known for its sharp-but-painterly image quality, but also an arrangement which has never been replicated on modern DSLR's (due to technical incompatibilities). Unlike modern lenses, however, it was designed to be used on a camera with the focusing mechanism built into the camera body, and not the lens - which means that adapting it to a mirrorless digital camera required expensive and obscure adapters.   
**Provided here is my first attempt at an elegant, 3D-printable integration between this lens and a modern camera. It cleanly adapts to Sony NEX / E-Mount cameras. It is also a good starting point towards a more general series of focusing adapters for various lenses, and proof-of-concept towards building 3D printed lenses in their entirety.**  
It is a single-helicoid focusing mechanism, which means the lens rotates as it focuses. (I have a design for a double-helicoid mechanism, but I think it will be a challenge to print with good results at this point.) The focus range is roughly 30cm to infinity. (Closer than history intended... several of the sample images above would not have been possible with a traditional adapter.)   

*Credit: I took the photos shown over the weekend with this lens and adapter. They are 70% beautiful because of my gorgeous girlfriend and stylish friends, 25% beautiful because the camera lens is amazing, and 5% beautiful because I was obnoxious enough to be there with a camera and hit the correct button.*  

**2013.09.15 - v1.12 Update:** *Oh boy, is this ever a sweet update. I've made a bunch of improvements, including:*  
- *A 3D printer-optimized threadform I developed based on extensive testing of printed helicoid accuracy. The threads now have continuous curvature in the plan view, meaning that jerk in the printhead is minimized while the adapter is being printed*.  
- *A finer thread pitch and longer focus throw, for closer focusing and easier micro-adjustments.*  
- *A spring-loaded section of threads which preload the helicoid as well as eliminate the need for a screw to function as a focus range limiter*  
- *Better light baffling on the inside of the lens mount*  
- *A better snap-fit for inserting the lens*  
- *A more precise fit for the E-Mount*  
What remains to be finished: Dialing in the perfect infinity focus stop. Right now, it focuses slightly past infinity.



See all issues or open a new issue


3141b0b378d11b0a1025713b1745e650?default=blank&size=40buildbot added this to the toprint collection ago
Ba5bae2796512ac180a31322167485e4?default=blank&size=40gulfsurfco added this to the THINGS collection ago
Dfc26b01fd1e18a1f573a90ce50830db?default=blank&size=40Sanne Geertman added this to the Personal collection ago
3fda67ddb49eb71fe36ecff5e7bfa586?default=blank&size=40AM3DP added this to the To Try collection ago
7a0f269f36a4ef6b66ccf84eb4f5fa60?default=blank&size=40Venosa added this to the Tools collection ago
04927929cb934be014240b433eb8049b?default=blank&size=40huubh added this to the Photography collection ago
9542d1c41342b5dbc093d1fcb363ef86?default=blank&size=40ulises kurosawa added this to the Cámara collection ago
077e146d5f7d17eb409d591e11311bd6?default=blank&size=40Daniele Ribolla added this to the shotty's awesomes collection ago
Mini  sushi chops trans more centeredSushi Desires added this to the Upgrades collection ago
Mini  sushi chops trans more centeredSushi Desires added this to the Home collection ago
Mini  sushi chops trans more centeredSushi Desires added this to the Tools collection ago
Mini  sushi chops trans more centeredSushi Desires added this to the Curios collection ago
Mini  sushi chops trans more centeredSushi Desires added this to the Mechanisms collection ago
D79c33ce898647deef4b56bbc6962020?default=blank&size=40Alican B. added this to the Camera things collection ago
F002b4d63499f6c5f6f84ae64ac3c1b8?default=blank&size=40dirt.rocket added this to the Stuff collection ago
80d665ce2d893d9b2e73663b305556a7?default=blank&size=40Ilkka Kiistala added this to the DSLR collection ago
Aa53046b3ddb1b487a3a2a1478bfb99b?default=blank&size=40rmalacka added this to the Photo collection ago
62a6367c7c94d3d5a64d0aa409599a39?default=blank&size=40Brian Kyle added this to the Photography collection ago
Mini sp logo grain 400x390Stamos added this to the photographic collection ago
D7ce4d7840b4ac2e1413e900f4cba6c6?default=blank&size=40Chia Yuan Lin added this to the Tools and Holders collection ago
Mini bobblejot iphone 6Gareth Price added this to the Cameras collection ago
Mini dsc06896 1nhfoley published this design ago