How to Identify a Lens Mount

By Tom Lutzenberger

SLR cameras come with different lens mount designs depending on the brand.
i film-camera on camera-bag image by Andrii Oleksiienko from

If you start to get into photography as an amateur, you will very likely start to begin a collection of camera lenses. This trend is most common with single lens reflex cameras or SLRs. Along these lines, to save money at first you will probably find yourself attracted to used equipment at cheaper prices. However, with so many cameras having been on the market over the decades, there are at least five times as many lenses. They also sell with different mounting designs. It's important to know how to distinguish one mounting type from another.

Decide which of your cameras for which you are obtaining or referencing lenses. Pay particular attention to the camera brand. Find the camera model reference book that came with your camera. Turn on your computer and download it from the Internet if you do not have a copy handy. Turn to the table of contents or the index and find the section covering "lenses."

Read the reference book to identify your camera mounting type and the lens format it will take. Write this information down on a notepad along with the camera brand name (i.e. Canon, Nikon, Pentax, Minolta, etc.). Take the notepad with you as you browse or look at lenses you may want to purchase or obtain.

Hold the subject lens carefully with both hands. Look on the side of the lens for any description of the lens format type; for example, Canon lenses are labeled FD, EF, EF-S, etc. Compare the lens format you find on the lens with the format described by your reference book. Discard any lenses that don't match the format you need.

Examine how the lens you are interested in attaches to a camera. Determine if the lens is a screw-in type with thin threads around the lens end, a bayonet style which comes with three edges that must line up correctly, or a friction lock design which is generally found on movie camera type lenses. Refer back to your camera manual to know which lens style works for your camera. Also know that many brands manufacture all of their lenses using the same mount, so that the brand lens will fit on the same brand camera body.

Bring your camera with you if purchasing expensive lenses or third party lenses, even used ones. Take the lens and test that it will install and work on your camera, even if you have confirmed it is the right format per the side detail already seen when referencing. Turn your camera on and allow the camera to autofocus the lens a few times to be sure. Remove the lens after testing and make a decision to purchase or not.