Getting started with cameras can be a bit confusing, especially when you start looking at lenses. You might see terms like EF and EFS and wonder what they mean for your photos. It’s a common question, and sometimes it feels like there’s a lot to figure out.
But don’t worry! This guide will break down the ef lens vs efs lens difference in a really easy way, step by step. After this, you’ll know exactly which lens is right for your camera and your photography adventures.
Understanding EF And EFS Mounts
When you look at Canon cameras, you’ll notice they use different types of lens mounts. The two main ones you’ll encounter are EF and EFS. These names sound similar, but they refer to fundamentally different types of lenses that work with specific camera bodies.
The mount is the part of the camera that the lens screws or clicks into. It’s like a connector that allows the lens and the camera body to talk to each other and work together.
The difference between EF and EFS is mainly about the sensor size of the camera they are designed for. This is a pretty important detail because using the wrong lens can mean you either can’t attach it at all, or it won’t function correctly.
What Does EF Mean?
EF lenses are designed for Canon’s full-frame cameras. Think of full-frame cameras as having a sensor that’s the same size as a traditional 35mm film frame. This means that when you put an EF lens on a full-frame camera, you get the full field of view that the lens was designed to capture.
It’s like seeing the whole picture without anything cut off.
These lenses are generally built with higher quality materials and optics, often leading to better image quality, especially in low light and for things like background blur (bokeh).
Because they are designed for full-frame sensors, EF lenses can be used on both full-frame cameras and Canon’s APS-C sensor cameras (which we’ll talk about next). However, when you put an EF lens on an APS-C camera, something interesting happens. The APS-C sensor is smaller than a full-frame sensor.
This means it only captures the central part of the image that the EF lens projects. This effect is often called a “crop factor.”
So, if you have an EF lens and an APS-C camera, the image you get will look like it was taken with a longer focal length lens. For example, a 50mm EF lens on an APS-C camera might give you a field of view similar to a 75mm or 80mm lens on a full-frame camera. This can be useful if you want to “zoom in” without actually having a zoom lens, like for wildlife or sports photography.
Key characteristics of EF lenses:
- Designed for full-frame Canon EOS cameras.
- Can be used on APS-C Canon EOS cameras, but with a crop factor.
- Often offer wider maximum apertures for better low-light performance.
- Typically have higher build quality and optical performance.
- Generally more expensive than EFS lenses.
What Does EFS Mean?
EFS lenses, on the other hand, are specifically designed for Canon’s APS-C sensor cameras. APS-C cameras have a smaller sensor size compared to full-frame cameras. The “S” in EFS actually stands for “Stretched” or “Smaller,” indicating it’s made for this smaller sensor format.
When you use an EFS lens on an APS-C camera, you get the full field of view that the lens is designed for, without any cropping. It’s made to fit that particular sensor size perfectly.
However, EFS lenses are NOT compatible with Canon’s full-frame cameras. If you try to put an EFS lens on a full-frame Canon body, it simply won’t mount correctly, or if it does somehow attach, it will likely cause vignetting (dark corners) and may not function at all. The image circle projected by the EFS lens is too small to cover the entire full-frame sensor.
EFS lenses are often more affordable and lighter than their EF counterparts. They are a fantastic choice for beginners and enthusiast photographers who own APS-C Canon cameras. They offer excellent value and are capable of producing beautiful images.
Key characteristics of EFS lenses:
- Designed specifically for APS-C sensor Canon EOS cameras.
- Cannot be used on Canon full-frame cameras.
- Provide the intended field of view on APS-C bodies without cropping.
- Generally more compact and lightweight.
- Typically more budget-friendly.
EF Lens vs EFS Lens Compatibility Table
To make things super clear, let’s look at how these lenses work with different camera types. This table shows you what fits and what doesn’t.
| Lens Type | Full-Frame Camera | APS-C Camera |
|---|---|---|
| EF Lens | Yes (Full Field of View) | Yes (With Crop Factor) |
| EFS Lens | No (Will not mount or function correctly) | Yes (Full Field of View) |
The Crop Factor Explained
We’ve mentioned the “crop factor” a couple of times, and it’s a key concept when you’re comparing ef lens vs efs lens, especially if you have an APS-C camera. Remember, APS-C sensors are smaller than full-frame sensors.
This size difference means that when a lens projects its image circle onto the sensor, the APS-C sensor only captures the middle part of that circle. It’s like looking through a window that cuts off the edges of the scene the lens is seeing.
The crop factor is a multiplier that tells you how much “zoomed in” your image will appear compared to a full-frame camera. For Canon APS-C cameras, this multiplier is typically around 1.6x.
Here’s how it works in practice:
- If you put a 50mm EF lens on a full-frame camera, it behaves like a 50mm lens.
- If you put that same 50mm EF lens on a Canon APS-C camera, the field of view will be equivalent to a 50mm x 1.6 = 80mm lens on a full-frame camera.
- If you put a 35mm EFS lens on an APS-C camera, it behaves like a 35mm lens on that camera. If you were to calculate the full-frame equivalent, it would be 35mm x 1.6 = 56mm.
This crop factor can be a good thing or a challenge, depending on what you’re shooting. For instance, if you love shooting distant subjects like birds or sports, the crop factor can give you extra “reach” without needing a more expensive telephoto lens. However, if you’re trying to capture wide-angle shots, like landscapes or group photos in tight spaces, you might find that even your widest lenses feel a bit too zoomed in on an APS-C camera.
When To Choose EF Lenses
You’ll likely want to consider EF lenses if you own or plan to own a Canon full-frame camera. These cameras are designed to take full advantage of the image circle that EF lenses produce. This allows you to capture the widest possible field of view that the lens is capable of.
EF lenses also offer a vast selection, from very affordable prime lenses to high-end professional zoom lenses. They often have wider maximum apertures (like f/1.2, f/1.4, or f/1.8) which are excellent for shooting in low light and creating beautiful background blur. If you’re serious about low-light photography, portraits with creamy bokeh, or capturing the highest possible image quality, EF lenses on a full-frame body are the way to go.
Even if you currently own an APS-C camera, investing in an EF lens can be a smart move for the future. As mentioned, EF lenses work on APS-C cameras (with the crop factor), so you can use them now and then take them with you if you upgrade to a full-frame camera later. This can save you money in the long run compared to buying EFS lenses now and then needing to
However, be mindful of the cost. High-quality EF lenses can be a significant investment. Also, remember that on an APS-C camera, an EF lens will always have that crop factor, which will affect your field of view.
When To Choose EFS Lenses
EFS lenses are the perfect choice if you have a Canon APS-C camera and you’re looking for lenses that are designed to work perfectly with it. They are usually more affordable, lighter, and more compact than comparable EF lenses.
For everyday shooting, travel, or if you’re just starting out and want to build your lens collection without breaking the bank, EFS lenses are an excellent option. They provide a great balance of quality, price, and performance for APS-C photographers.
The key advantage of EFS lenses on an APS-C camera is that you get the intended wide-angle capabilities. If you want to shoot landscapes that capture a vast scene or take photos in tight indoor spaces, an EFS wide-angle lens will give you a much wider perspective than an EF lens of the same focal length on an APS-C body.
It’s also important to remember that EFS lenses are specifically optimized for the smaller APS-C sensor. This means they can sometimes be designed to be smaller and lighter, as they don’t need to project as large an image circle as EF lenses. This can make them more convenient to carry around.
Can You Adapt Lenses?
Generally, you cannot adapt Canon EFS lenses to work on other camera brands, or Canon EF lenses to EFS mounts. The physical mount and electronic connections are proprietary to Canon. However, there are adapters that allow you to mount lenses from one Canon mount type to another, but these often come with limitations or are not recommended for general use.
For example, Canon does not make adapters to mount EFS lenses onto EF mounts or vice versa. The physical and electronic designs are simply too different. If you buy an EFS lens, it is intended for an EFS mount camera.
If you buy an EF lens, it can be used on both EF mount (full-frame) and EFS mount (APS-C) cameras.
The most common adaptation scenario is using lenses from different camera systems (like Nikon, Sony, or mirrorless brands) on a Canon body, or vice versa, using specialized adapters. But for the ef lens vs efs lens debate specifically within the Canon ecosystem, it’s usually a matter of direct compatibility.
Which One Is Right For You?
Deciding between EF and EFS lenses really comes down to your camera and your photography goals. Let’s recap to help you choose:
- If you have a Canon full-frame camera (like a 5D, 6D, or R-series with an EF adapter): You should use EF lenses. They are designed to give you the full image quality and field of view on your camera.
- If you have a Canon APS-C camera (like a Rebel series, 70D, 80D, 90D, or M-series with an EF adapter): You can use both EF and EFS lenses.
- Choose EFS lenses if you want to save money, keep your gear lighter, and get the widest possible field of view from your lenses. They are designed to perform at their best on your APS-C sensor.
- Choose EF lenses if you want the option to use them on a full-frame camera in the future, or if you want access to a wider range of professional-grade lenses and features like wider apertures, and you’re okay with the crop factor they introduce on your APS-C camera.
Think about what you like to photograph most. If you love wide landscapes, EFS might be your friend. If you are constantly shooting distant subjects and want more reach, the crop factor from an EF lens on an APS-C can be helpful.
If you dream of owning a full-frame camera one day, starting with EF lenses can be a wise investment.
Frequently Asked Questions
Question: Can I use an EF lens on an EFS mount camera
Answer: Yes you can use an EF lens on a Canon APS-C camera which has an EFS mount. The lens will work but it will be cropped meaning the image will look more zoomed in than it would on a full-frame camera.
Question: Can I use an EFS lens on a full-frame camera
Answer: No you cannot use an EFS lens on a Canon full-frame camera. The lens is designed for the smaller APS-C sensor and will not cover the entire sensor of a full-frame camera. It will either not mount correctly or will produce a very dark image with heavy vignetting.
Question: What is the main difference between EF and EFS lenses
Answer: The main difference is the sensor size they are designed for. EF lenses are for full-frame sensors while EFS lenses are for APS-C sensors. This affects the field of view and compatibility with camera bodies.
Question: Are EF lenses always better than EFS lenses
Answer: Not necessarily. EF lenses are generally designed for higher-end full-frame cameras and often offer superior optics and build quality. However EFS lenses are optimized for APS-C cameras and can provide excellent image quality and value for those camera systems.
The “better” lens depends on your camera and what you want to achieve.
Question: Will an EF lens on an APS-C camera have the same focal length as stated
Answer: No. When you use an EF lens on an APS-C camera there is a crop factor (typically 1.6x for Canon). So a 50mm EF lens will give you a field of view equivalent to an 80mm lens on a full-frame camera.
Final Thoughts
Understanding the distinction between EF and EFS lenses is a key step in making the right choices for your photography gear. For Canon users, this choice largely hinges on whether your camera has a full-frame or APS-C sensor. If you have a full-frame camera, EF lenses are your primary and best option to capture the full potential of your sensor.
If you’re working with an APS-C camera, you have the flexibility to use both EF and EFS lenses. EFS lenses offer a more budget-friendly and compact solution specifically designed for APS-C, providing you with the intended wide-angle views. On the other hand, EF lenses on an APS-C camera will give you that beneficial crop factor, which can be great for telephoto reach, and they also prepare you for a future upgrade to a full-frame system.
When you’re selecting your next lens, think about your current camera body, what kind of photography you enjoy most, and your budget. Don’t be afraid to experiment with different focal lengths and types of lenses. Many photographers find a combination of both EF and EFS lenses serves their needs well over time, especially if they start with an APS-C camera and later move to a full-frame body.
The most important thing is to choose lenses that help you capture the images you envision.
