SimMount Contax Zeiss to EF Conversion Kit

Vintage lenses were never designed to live in a modern cinema ecosystem.
This is how you bring them in properly.

The Simmod SimMount Contax Zeiss to EF Conversion Kit is a precision-engineered system that converts Contax Zeiss lenses into a native Canon EF mount, allowing seamless integration with both still and cinema camera platforms.

A True Mount Conversion

This is not an adapter sitting between lens and camera.
This is a direct mount replacement.

The SimMount system replaces the original Contax/Yashica mount with a dedicated EF mount, creating a rigid, unified connection between lens and camera. By eliminating intermediary adapters, it removes tolerance stacking, play, and mechanical inconsistencies.

The result is a lens that behaves like it was designed for EF from the start.

Engineered for Mechanical Stability

Contax Zeiss lenses demand precision when integrated into modern systems. Internal optical alignment depends on a mount that remains consistent under real-world use.

This conversion is built to maintain that integrity.

• Preserves accurate flange distance

• Maintains infinity focus and optical alignment

• Ensures consistent performance during operation

If the mount shifts, the image shifts. This system prevents that.

Precision Construction

The SimMount is manufactured from high-quality aircraft-grade brass, finished in a matte black coating to reduce reflections and internal glare.

• CNC-machined for tight tolerances

• Secure, play-free fit

• Designed for long-term durability in production environments

This is built to withstand real use, not occasional handling.

Expanded Compatibility

Once converted, your Contax Zeiss lens becomes compatible with:

• Canon EF and EF-S cameras

• EF-mount cinema cameras and production systems

This opens up vintage glass to modern workflows without compromising reliability.

Installation Approach

The system is designed for straightforward installation:

• Remove the original mount by loosening factory screws

• Align and place the SimMount onto the lens

• Secure using the original or supplied screws

Proper tools and care are recommended, as factory screws are often secured with adhesive.

Why It Matters

Vintage lenses are often limited by their original mount, not their optical performance.

This conversion changes that.

• Your lens becomes native to your camera system

• Stability improves across all shooting conditions

• Focus accuracy and repeatability are preserved

• Your setup becomes more reliable in demanding environments

The Simmod Approach

Simmod does not build around convenience. It builds around control. The SimMount Contax Zeiss to EF Conversion Kit is designed to bring structure, precision, and reliability to lenses that were never intended for this level of performance. It allows vintage glass to function with confidence in modern cinema systems.

A classic lens, properly mounted.