Canon XSi/450D

Canon interchangeable lens designations

Written by Digicamhelp Editor

Understanding the Canon interchangeable lens designations can be difficult for a new Canon DSLR user. But once you do, be forewarned, you’ll get the phrase “lens envy.”

Canon lensesIt can be dizzying deciding which lenses to buy for a digital single lens reflex camera. As a new DSLR user, I decided to play it safe and buy good, but inexpensive, lenses until educating myself more fully about other options.

I bought a Canon XSi/450D with the kit lens (EF-S 18-55mm f/3.5-5.6 IS) but within days realized I missed the reach of a long zoom.

I soon bought the Canon EF-S 55-250mm f/4.0-5.6 IS telephoto zoom lens at a local camera shop. I have about $400.00 invested in these two image stabilized lenses.

When it comes to cost of DSLR lenses, $400.00 isn’t a lot of money. But I think it’s wise to start modestly until I give myself more time to know if I need better lenses. The two I have are quite good and meet my current photographic needs. They are relatively compact and lightweight and I like that.

Canon lens designations

EF-S lenses

EF-S lenses are designed for Canon DSLR cameras that are not full frame. EF-S lenses are considered budget lenses, but that doesn’t mean they are not good lenses. You get a lot for the small investment, particularly the newer lenses with Image Stabilization.

These lenses are compact and lightweight. They don’t have some of the features found on more expensive lenses, but not everyone needs those features. Nor do they want the extra expense of a better lens.

EF-S lenses can only be used with 1.6 crop cameras (cameras like the XSi that have sensors smaller than the size of a 35mm film plane). EF-S lenses won’t fit on full-frame cameras.

EF lenses

EF lenses fit all Canon EOS series cameras with the EF-mount. It’s important to note that third-party lenses may have compatibility issues one some Canon EOS bodies with EF-mounts.

Ultra Sonic Motor (USM)

Lenses that are designated USM have autofocus motors that are both fast and silent. Many new lenses available today are much quieter and faster than in the past. Buying a lens for the sole reason that it is marked USM may not be worth the extra money.

Canon “L” lenses

Click on the above image and take a closer look at this baby!

Canon 100-400mm IS L lens mounted on the XSi. Click the image and take a closer look!

Used by professionals and non-professionals who can afford them, L-series are Canon’s professional, top-of-the-line lenses. Among other things, lenses with the L designation offer outstanding optical performance, excellent build quality and they focus very fast.

L lenses are as good as it gets.

L-series lenses can be identified by the red ring near the end of the lens. Some L-series lenses are white. Many L-series lenses have wide apertures that remain fixed throughout the entire zoom range.

As of this writing, there are no designated Canon L-series lenses for EF-S cameras like the XSi. However some lenses, such as the Canon EF-S 10-22mm and EF-S 17-55mm, have the same high quality glass elements and image quality as some L-series lenses.

Photographers use the phrase “lens envy.” Once you use an L lens, you’ll fully understand the term.

DO (diffraction optics)

A DO lens is an expensive, high end lens designed to be lighter and smaller than other lenses in its class. According to some photographers who use and like DO lenses, controlling flare can be a challenge.

Dust off your wallet!