What is the difference between a Canon EF lens and an EF-S lens mount? What types of cameras are compatible with these lenses? Do they have any effect on image crop? How does the image quality differ when you use an EF or an EF-S lens?
All of these questions can be quite confusing for a novice who has just bought his first Canon DSLR camera. However, you need not worry because we are going to explain the difference between EF and EF-S lenses in detail besides highlighting some of their advantages and disadvantages.
What is a Lens Mount?
Lens mount is the place where the lens connects with your camera. Both the lens and the camera have certain components that combine to make the lens mount. Keep in mind that certain cameras only work with specific types of lenses. For example, EF-S lenses can only fit on cameras with an EF-S lens mount that are Canon APS-C digital cameras to be specific.
Similarly, lens mounts differ from company to company. Mounts created by Canon are different from that of Nikon and Sony altogether. Furthermore, the same company may have different lens types for different camera series. For example, Canon RF lenses are only compatible with their R series mirrorless cameras. You cannot use them on any other type of camera.
Even more, even similar camera systems such as Canon DSLR cameras (both full-frame and APS-C) may have different lens mounts. The Canon EF and EF-S lenses fall in the last category.
Canon EF vs EF-S Lenses
Dating back to 1987, Canon EF lenses are used for Canon full-frame DSLR cameras. It is one of the most popular lens families in the world. The EF refers to “Electro Focus” meaning it contains an electronic motor to focus. Similarly, the lens and the camera communicate with each other automatically without having any mechanical parts.
Canon introduced EF-S lens mount in early 2000s for their APS-C or crop sensor DSLRs. EF and EF-S lenses are essentially the same. The only difference is you can use EF-S lenses only on Canon APS-C DSLRs. They have smaller image circle and therefore, cannot be used on full-frame Canon DSLRs.
Designed for full-frame Canon DSLRs, EF lenses have larger image circle. Therefore, they can also work with APS-C sensors but with a caveat. Since APS-C sensors have a substantial image crop, they will not capture the entire image circle produced by the EF lens. As a result, the image will look zoomed-in besides having low resolution.
Should I Buy an EF or EF-S Lens?
It depends on your requirements and sensor of your camera. You should preferably buy an EF lens for full-frame DSLRs and an EF-S lens for an APS-C DSLR. An EF lens on a full-frame camera will offer you 100% coverage besides a wide-angle of view. Therefore, it is perfect for architecture and landscape photography.
Similarly, EF lenses usually have excellent build quality with features like weather sealing and waterproofing. They are an excellent choice for professionals. All of these features mean EF lenses are much more expensive than EF-S lenses as well.
You can also use an EF lens on an APS-C camera if you want a narrow field of view such as for sports and wildlife photography that require an extremely long reach. Once again, the image will have some level of crop or vignetting. You can remove it during post-processing but it will reduce resolution, limiting your printing options. Similarly, it will also increase your editing time.
Compared to EF lenses, EF-S lenses are not only cheaper but smaller as well. Therefore, they are more budget-friendly and don’t put much burden on you while traveling.
I hope you understand the difference between an EF and EF-S lens now. You can use both EF and EF-S lenses with Canon DSLRs depending on their sensor type. Both types of lenses offer excellent image quality and can help you take some stunning pictures.