Canon LENS ASS/'Y, EMD, 3&4&5 GROUP

Restoring a professional Canon lens to factory optical performance demands precision components that match the original design exactly. The Canon CY3-2348 Lens Assembly is an authentic OEM replacement module containing optical groups 3, 4, and 5 along with the integrated Electro-Magnetic Diaphragm (EMD). Unlike generic aftermarket alternatives that may introduce alignment errors or inconsistent aperture behavior, this genuine Canon part is manufactured to the same tolerances as the components installed during initial lens production. It is intended for professional service environments where reliable optical alignment and electronic aperture control are non-negotiable.

Highlights

• Genuine Canon OEM replacement assembly for select EF and RF lenses
• Includes optical groups 3, 4, and 5 as a matched set
• Integrated Electro-Magnetic Diaphragm (EMD) for precise aperture control
• Precision optical glass elements housed in a durable metal and engineering plastic structure
• Restores both image quality and automatic exposure functionality
• New condition, supplied as a service part for professional repair

In daily use

Technicians replacing this assembly will appreciate the exact fit and electronic compatibility with the lens body. The EMD unit responds instantly to camera commands, ensuring accurate exposure across all aperture settings. Because the three optical groups are pre-aligned within the assembly, the risk of decentering is minimized compared to replacing individual elements. This part is essential for repairing lenses suffering from impact damage, aperture failure, or internal element misalignment. Installation requires specialized tools and technical expertise, and it is recommended only for qualified service personnel.

Full specifications

• Manufacturer: Canon Inc.
• Part number: CY3-2348
• Component type: Optical group and EMD assembly
• Optical groups included: 3, 4, and 5
• Diaphragm type: Electro-Magnetic Diaphragm (EMD)
• Application: Professional lens repair and service
• Material: Precision optical glass, metal housing, engineering plastics
• Condition: New, genuine OEM
• Compatibility: Specific Canon EF/RF lenses (refer to service manual)

Final note

Choose the Canon CY3-2348 to bring your lens back to original specifications with confidence, backed by Canon's manufacturing quality and exacting standards.