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All You Need To Know About Canon Lens Terminologies


If you’re somewhat new to Canon and are trying to manoeuvre around the different lenses available, abbreviations like IS, EF, and USM imprinted on the products could throw you off guard. To help you out, we’ve compiled the 18 most common Canon lens terminologies into a handy infographic so you’ll be more savvy with the jargon for when you’re next looking for an upgrade! Check it out below.

EF stands for Electro-focus, which means that the automatic focusing on EF lenses is handled by an electric motor built into the lens. EF lenses can be used on all Canon DSLR bodies and even Canon’s mirrorless range (EOS M series) with an EF-EOS M adapter. One such lens is the Canon EF 70-300mm f/4-5.6 IS II USM Telephoto Zoom Lens.

EF-S stands for Short Back Focus. The difference between EF and EF-S lens is that EF-S lens is a smaller design suitable for Canon digital cameras with APS-C sensors, such as the Canon EOS 90D. They are also cheaper, lighter and the recommended lens range for beginners to start their photography journey before upgrading to the full-frame lens.

EF-M (Electro Focus Mini/Micro) lens is made for the Canon EOS M mirrorless series. The M in EF-M lens refer for mobility and like the EF-S lens, they too are designed for APS-C sensors.

The Canon RF lens mount is developed for its full-frame mirrorless interchangeable lens cameras.

The MP-E lens is made for very high magnification from 1:1 to 5:1. It is also a manual-focus only lens.

IS is Canon’s abbreviation for Image Stabilization where it counteracts against movement blur to provide sharper image output when the slow shutter speed is utilised. It is especially useful for shooting non-moving subjects in low-light conditions.

The Roman numerals represent the lens’ generation. An example of a lens with three generations would be the Canon EF 16-35mm f/2.8L USM lens, Canon EF 16-35mm f/2.8L II USM lens, and Canon EF 16-35mm f/2.8L III USM lens.

USM means Ultrasonic Motor, which is for fast and quieter focusing. There are three types of USM motor such as the ring-type, Micro I and Micro II types. USM lenses are great for wildlife and wedding photography, where low-noise output is required. It is also the most used motor for Canon lenses. Read more on USM lenses here.

The Stepper Motor lens is introduced to better the video output from Canon lenses. It provides quieter and smoother autofocus during movie recordings as it uses a focus-by-wire system (the focus ring controls a motor and moves the internal elements). Check out our repertoire of STM lens articles here.

As the name suggests, Macro lenses are made for close-up photography, also known as macro photography. The lenses usually feature a magnification ratio of 1:1 and can capture intricate details in close distance. Macro lenses will usually have a fixed focal length, and the subject choices include water droplets, insects, food, jewellery and flowers.

TS-E refers to Tilt-Shift Lenses and they are manual focus lenses that allow users to reposition the optics by shifting it up and down or left and right. Also, the front section of the lens can be tilted at an angle upward, downward, left or right to adjust the output’s perspective. This shifting mechanism is used to correct the keystone effect (or pyramid effect) when photographing tall subjects such as buildings and trees.

DO lenses refer to Diffractive Optics. The advantages of DO lenses are that it is much smaller and lighter than other lenses of the same parameters. This is due to the use of special glass elements that bend light more than regular glass, which cuts down the size of the lens and thus reduces the weight. You can identify DO lenses by the green ring around the ring barrel like the telephoto EF 400mm f/4 DO IS USM.

One of the top products suited for professionals, the L lenses (Luxury) are identified by the bold red ring around the lens’ frontal end which showcases the professional-grade optics. All L lenses come with USM (Ultrasonic Motor), wider aperture setting, and are built with protection against weather and dust. Due to that, they are priced higher than other conventional lenses. Check out the image quality of L-series lenses here!

BR lens refers to the Blue Spectrum Refractive optics, and is a compound lens that corrects blue wavelength colour fringing in your output.

ASC, or otherwise known as the Air Sphere Coating, is a lens coating technology developed to significantly enhance the anti-reflective properties of lenses.

DS refers to Defocus Smoothing, and it allows out of focus areas (bokeh) to have a gradient feathering effect that soften the edges.

SWC technology is a Subwavelength Structure Coating lens technology that makes it possible to control flare and ghosting even on lens surfaces that previously did not benefit from any anti-reflective effect from evaporated film coating.

Heat Shield
Some Canon lenses utilise infrared reflective Heat shield coating to prevent overheating when shooting in the hot sun or environment.

Now that you have a better understanding of Canon lens terminologies, you can better plan for your next upgrade or any additions to your collection. Watch out for our All You Need To Know About Canon DSLR Terminology Glossary article Part II to complete this glossary series!

Download a copy of this infographic here.