Are you confused about Canon camera lenses? Many people are unsure about the difference between EF and EFS lenses. It can seem a bit tricky at first, but don’t worry!
This guide breaks down the ef vs efs lens issue in a simple way. We will walk through everything you need to know, step by step, so you can pick the right lens for your camera and your photos. Let’s get started!
Canon EF vs EFS Lenses What’s The Big Deal
What Are Canon EF Lenses
Canon EF lenses are designed for full-frame digital SLR (DSLR) cameras. Think of a full-frame sensor as the largest sensor size in Canon’s DSLR lineup. Because the sensor is larger, it captures a wider field of view.
EF lenses use a different mount system than EFS lenses. This mount is the connection point between the camera body and the lens.
When you attach an EF lens to a full-frame Canon camera, it will cover the entire sensor. This means you get the full picture that the lens is designed to produce. These lenses are often larger, heavier, and can sometimes be more expensive than EFS lenses.
They are built to deliver high-quality images with excellent sharpness and color reproduction, making them a popular choice for professional photographers and serious hobbyists.
What Are Canon EFS Lenses
Canon EFS lenses, on the other hand, are made specifically for Canon’s APS-C sensor DSLRs. APS-C sensors are smaller than full-frame sensors. Because the sensor is smaller, it effectively “crops” the image projected by the lens.
This cropping effect means that an EFS lens, when used on an APS-C camera, will have a narrower field of view compared to what it would produce on a full-frame camera. It’s like looking through a smaller window.
The EFS mount is also different from the EF mount. This difference is important because it means EFS lenses will NOT physically fit on full-frame Canon cameras. The camera body will simply not allow them to attach due to the differing mount designs and flange back distances.
EFS lenses are typically designed to be lighter, more compact, and often more affordable than their EF counterparts. They are a great option for beginners and enthusiasts who use Canon’s APS-C camera bodies.
Key Differences Explained
The most significant difference between EF and EFS lenses lies in their sensor compatibility. This is the primary factor that causes confusion for many photographers, especially when they are new to the Canon system. Understanding this distinction will help you avoid costly mistakes and ensure you are choosing the right lens for your camera.
Sensor Size Compatibility
As mentioned, EF lenses are built for full-frame sensors, while EFS lenses are designed for APS-C sensors. Here’s a breakdown:
- EF Lenses: Compatible with both full-frame and APS-C Canon DSLR bodies. When used on an APS-C body, they will still work, but the image will be cropped, resulting in a narrower field of view (often referred to as a “crop factor”).
- EFS Lenses: ONLY compatible with Canon APS-C DSLR bodies. They will NOT mount or function on Canon full-frame DSLR bodies.
Mount Design
The physical mount that connects the lens to the camera body is different. This is why an EFS lens cannot be attached to a full-frame camera. The mount also influences the lens’s internal design and how it projects an image circle onto the sensor.
Image Circle Projection
An EF lens projects a larger image circle that is designed to cover the entire sensor of a full-frame camera. An EFS lens projects a smaller image circle, which is sufficient to cover only the smaller APS-C sensor.
Focal Length and Field of View
Because of the crop factor associated with APS-C sensors, the effective focal length of a lens appears longer when used on an APS-C camera compared to a full-frame camera. For example, a 50mm lens on an APS-C camera behaves like approximately a 80mm lens (using a common 1.6x crop factor for Canon APS-C) in terms of field of view. EFS lenses are designed with this crop factor in mind, meaning a 17-55mm EFS lens on an APS-C camera will give you a wide-angle to standard view, similar to a 27-88mm lens on a full-frame camera.
EF lenses, when used on an APS-C camera, also experience this crop factor. So, a 50mm EF lens on an APS-C camera will appear as an 80mm lens. This means you can use EF lenses on APS-C bodies, and they will function, but you won’t get the true wide-angle performance that lens offers on a full-frame camera.
Size and Weight
Generally, EFS lenses tend to be smaller and lighter than comparable EF lenses. This is partly because they are designed for smaller sensors and don’t need to project as large an image circle. This can be a significant advantage for photographers who prioritize portability.
Cost
EFS lenses are often more affordable than EF lenses. This makes them an excellent entry point for photographers who are on a budget or are just starting out. While there are high-end EFS lenses available, the overall price range for EFS is typically lower.
Can You Use EF Lenses On EFS Cameras
Yes, you absolutely can use EF lenses on Canon APS-C (EFS mount) cameras. When you mount an EF lens onto an EFS body, the camera will automatically recognize it and engage the crop factor. You will get images that have a narrower field of view than what the lens is rated for on a full-frame camera.
This means you can take advantage of the wider range of EF lenses available, even if you own an APS-C camera.
It’s important to remember that the camera will electronically adjust for the EF lens, and the autofocus and metering will work just fine. The only difference you will notice is the narrower field of view. Many photographers with APS-C cameras choose to use EF lenses to gain access to specific focal lengths or features not available in the EFS lineup, or simply because they want the flexibility to upgrade to a full-frame camera in the future without replacing their lenses.
Can You Use EFS Lenses On EF Cameras
No, you cannot use EFS lenses on Canon full-frame (EF mount) cameras. The physical mount of an EFS lens is different, and it will not physically attach to a full-frame camera body. More importantly, the EFS lens projects a smaller image circle that is not large enough to cover the entire sensor of a full-frame camera.
Even if you could somehow force it to mount, the resulting image would be heavily vignetted (darkened corners) and unusable.
This incompatibility is a key point of distinction and a common source of confusion. If you own a full-frame Canon camera, you must use EF or EF-S (which is essentially the same as EFS but often used interchangeably, though EF-S is the official Canon designation) lenses. If you own an APS-C Canon camera, you can use both EFS and EF lenses.
Choosing The Right Lens For You
Deciding between EF and EFS lenses primarily depends on the type of Canon camera you own and your photographic needs. Here’s a simple guide:
If You Have A Canon APS-C DSLR Camera
You have the most flexibility. You can use both EFS lenses and EF lenses.
- Choose EFS lenses if: You want the most affordable, often lighter and more compact options specifically designed for your camera’s sensor size.
They offer great value for everyday shooting, travel, and learning photography.
- Choose EF lenses if: You need specific focal lengths or features not available in the EFS lineup, or if you plan to upgrade to a full-frame camera in the future and want to carry over your lenses. You’ll get the full potential of the lens when used on an APS-C camera, with the understanding of the crop factor.
If You Have A Canon Full-Frame DSLR Camera
You can ONLY use EF lenses. EFS lenses will not fit. You will get the true focal length and field of view that the lens is designed for.
Lens Mount Table
Here’s a quick reference table to help you remember compatibility:
| Lens Type | APS-C Camera Compatible | Full-Frame Camera Compatible |
|---|---|---|
| EF-S Lenses | Yes | No |
| EF Lenses | Yes (with crop factor) | Yes |
This table clearly shows the limitations and possibilities when combining different lens types with Canon DSLR bodies.
Examples of Popular Lenses
To illustrate the differences, let’s look at a couple of common lens types:
Wide-Angle Lenses
- EFS Wide-Angle: The Canon EF-S 10-18mm f/4.5-5.6 IS STM is a popular choice for APS-C cameras. On an APS-C body, this gives a very wide field of view, comparable to about 16-29mm on a full-frame camera. It’s lightweight and affordable.
- EF Wide-Angle: The Canon EF 16-35mm f/2.8L III USM is a professional-grade wide-angle zoom for full-frame cameras. On a full-frame camera, it provides a wide view from 16mm to 35mm. If you use this lens on an APS-C camera, the field of view would be cropped to roughly 26-56mm.
Standard Zooms
- EFS Standard Zoom: The Canon EF-S 17-55mm f/2.8 IS USM is a highly regarded lens for APS-C shooters, offering a constant f/2.8 aperture. Its field of view on an APS-C camera is like a 27-88mm lens on a full-frame.
- EF Standard Zoom: The Canon EF 24-105mm f/4L IS II USM is a versatile standard zoom for full-frame cameras. On a full-frame body, it covers a broad range. On an APS-C camera, it behaves like a 38-168mm lens.
Prime Lenses
- EF Prime Lens (often used on APS-C): The Canon EF 50mm f/1.8 STM is a very popular and affordable “nifty fifty”. On an APS-C camera, it acts like an 80mm lens, making it great for portraits. On a full-frame camera, it gives you a true 50mm field of view.
As you can see, the same lens can behave differently depending on whether it’s on an APS-C or full-frame camera, but the EF-S lens will only work on APS-C.
Understanding Crop Factor
The “crop factor” is a term used to describe the difference in sensor size between a full-frame camera and an APS-C camera. Canon’s APS-C sensors typically have a crop factor of 1.6x. This means that the image captured by an APS-C sensor is effectively magnified by 1.6 times compared to what a full-frame sensor would capture at the same focal length.
This is why a 50mm lens on an APS-C camera provides a field of view similar to an 80mm lens on a full-frame camera.
When choosing a lens, especially if you are using an APS-C camera, it’s helpful to consider this crop factor. If you want a wide-angle shot on your APS-C camera, you’ll need a lens with a shorter focal length (like an 10mm or 18mm EFS lens) to achieve a similar field of view to a wider EF lens on a full-frame camera.
Frequently Asked Questions
Question: Can I use my old film SLR Canon lenses on my new digital camera
Answer: Many older Canon FD mount lenses from film SLRs cannot be directly used on modern Canon EOS digital cameras without an adapter, and even then, they may have limitations with autofocus and electronic functions. However, if you have older Canon EF mount lenses from film EOS cameras, those will generally work fine on modern Canon EOS digital cameras, with the EF-S/EF compatibility rules applying.
Question: Will my EFS lens work if I buy a full frame Canon camera later
Answer: No, an EFS lens will not work on a Canon full-frame camera. You will need to purchase EF mount lenses for your full-frame camera.
Question: What is the main advantage of EFS lenses
Answer: The main advantages of EFS lenses are that they are typically smaller, lighter, and more affordable than comparable EF lenses, making them excellent choices for entry-level photographers and those using APS-C cameras.
Question: Can I use an EF lens on an EFS camera
Answer: Yes, you can use EF lenses on Canon APS-C (EFS mount) cameras. The camera will engage its crop factor, and the lens will function correctly, providing a narrower field of view.
Question: How does the crop factor affect image quality
Answer: The crop factor itself doesn’t directly affect image quality in terms of sharpness or noise. It affects the field of view, making it appear narrower. When using EF lenses on APS-C cameras, you are using the central portion of the lens’s image circle, which is typically the sharpest part, so image quality is generally excellent.
Final Thoughts
Choosing the right Canon lens comes down to understanding your camera’s sensor size and what you want to achieve photographically. For APS-C camera owners, the flexibility to use both EFS and EF lenses offers a wide range of creative possibilities, from budget-friendly everyday shooting with EFS to exploring specialized optics with EF. Full-frame camera users are limited to EF lenses, which are designed to take full advantage of their larger sensors.
Always double-check your camera’s mount type before purchasing a lens, and remember that while EF lenses offer broader compatibility, EFS lenses are specifically optimized for the APS-C experience. Consider your current gear, your future aspirations, and your budget to make the best lens choice for your photography.
