Complete Guide to Lens and Camera Body Compatibility:
Full Frame, APS-C, Micro Four Thirds and L-Mount

Understanding the differences to choose the right lens without mistakes

Lens and camera compatibility is essential for anyone who wants to get the most from their equipment. Understanding lens mounts and sensor formats helps you avoid purchasing mistakes and make the best use of every combination. In this RCE Foto guide, you will find everything you need to know about Full Frame, APS-C, Micro Four Thirds, L-Mount and Leica M lenses, with practical examples and useful advice.

Full Frame lenses are compatible with both Full Frame and APS-C cameras, provided they use the same mount

Which one should you choose?

Since Full Frame and APS-C lenses can use the same mount, how do I know which one to choose?

• Full Frame lenses can be used on both Full Frame and APS-C camera bodies with the same mount.
• When using a Full Frame lens on an APS-C camera, the equivalent focal length is calculated using a crop factor of ×1.5 for Nikon and Sony and ×1.6 for Canon.
• The crop factor depends on the camera sensor, not on the type of lens being used.

📌 Example: a Nikon AF-S 50mm f/1.8G Full Frame lens mounted on an APS-C camera provides a field of view equivalent to a 75mm lens.

APS-C lenses are designed primarily for APS-C cameras

Which one should you choose?

• APS-C lenses are designed to cover the smaller sensor found in APS-C cameras.
• Using them on a Full Frame DSLR may produce the well-known vignetting effect. On compatible mirrorless cameras, they generally activate automatic crop mode, meaning the Full Frame sensor is not used at its full resolution.
• However, with the exception of certain Canon combinations, APS-C lenses can also be used on compatible Full Frame cameras, subject to the limitations described above.
• Since an APS-C sensor is smaller than a Full Frame sensor, the equivalent focal length is calculated using the following crop factors:
  • ×1.5 for Nikon and Sony
  • ×1.6 for Canon

📌 Example: a Nikon AF-S DX 55-200mm APS-C lens mounted on a Nikon APS-C camera provides a field of view equivalent to approximately 82.5-300mm on Full Frame.

Micro Four Thirds Lens System

Compatibility guide

• Olympus became OM System, while retaining the same lens mount.
• Panasonic and Olympus jointly developed the Micro Four Thirds system, ensuring broad interchangeability and compatibility between lenses and camera bodies using this standard.
• This gives photographers access to an extensive and versatile range of lenses.
• Because of the smaller sensor, the equivalent focal length is calculated using a 2× crop factor.

📌 Example: an Olympus 25mm lens mounted on a Micro Four Thirds mirrorless camera provides a field of view equivalent to a 50mm lens on Full Frame.

L-Mount Alliance

One mount, countless possibilities

• The L-Mount was developed through a collaboration between Leica, Panasonic and Sigma.
• L-Mount lenses from all three brands are fully compatible with L-Mount camera bodies.
• All Panasonic L-Mount lenses are compatible with Leica L-Mount cameras.

Leica: Where past and present meet

Digital results with analogue lenses

• The historic Leica brand developed the M-Mount system for film cameras.
• The mount is still in production today, allowing analogue lenses to be used on digital Leica M camera bodies.
• The reverse is also possible: modern Leica M lenses can be used on compatible film camera bodies.

📌 All Leica M lenses, both analogue and digital, are compatible with Leica M cameras, whether film or digital.

Panasonic and Leica L-Mount

One mount for two leading brands

• Panasonic entered the Full Frame market by adopting the L-Mount system developed by Leica.
• Used on Leica SL and Panasonic S cameras, it allows lenses to be fully interchangeable.
• All Leica L-Mount lenses are compatible with Panasonic L-Mount cameras, and vice versa.

Sigma L-Mount: a rising star

A brand earning its place among the industry leaders

• Sigma lenses with the L-Mount are fully compatible with Sigma, Panasonic and Leica L-Mount cameras.
• Thanks to the L-Mount Alliance, photographers can freely combine camera bodies and lenses from different participating brands.

La continuazione della dinastia Leica

Coesistenza tra presente e passato

• Leica monta da sempre la baionetta M anche sulle digitali.
• Questo permette di usare ottiche analogiche su corpi digitali e viceversa.

Two brands, one mount

An alliance designed to meet every photographer’s needs

• Thanks to the L-Mount Alliance, photographers can freely use Leica and Panasonic lenses on compatible Leica SL and Panasonic S camera bodies.

One mount for multiple camera bodies

One lens, countless creative possibilities

• All Leica, Panasonic and Sigma camera bodies equipped with the L-Mount can use Sigma L-Mount lenses.
• This provides maximum flexibility while maintaining consistently high image quality.

How to make the right choice

Understanding compatibility between Full Frame, APS-C, Micro Four Thirds and L-Mount systems is essential for making an informed investment.

At RCE Foto stores and in our online catalogue, you can find used lenses tested by our specialised technicians and covered by a 2- or 4-year warranty, carefully selected to ensure maximum reliability.

Camera and lens system compatibility table

To help you choose the right equipment, we have brought together the main camera brands, their respective lens mount systems and their compatibility with different sensor formats in a single table.
This overview makes it easy to understand which lenses you can use with your camera, as well as any limitations or advantages.

From traditional Canon EF and EF-S mounts to modern Nikon Z and Sony E mirrorless systems, and the Micro Four Thirds system shared by Olympus (OM System) and Panasonic, the table clearly shows which combinations work without adapters and where extra care is required.

It also includes the Leica, Sigma and Panasonic systems within the L-Mount Alliance, as well as specialist medium-format brands such as Fujifilm and Hasselblad.
A useful resource for anyone looking to purchase RCE Foto guaranteed used lenses and make sure they are compatible with their camera.