Lens Lingo – What do all the letters and numbers on a lens mean?

I am sure that at some point you have looked at your lens and said to yourself  “I wonder what all the numbers and letters mean?”, so I decided to write a little about each letter or number for the most common lens makes.

Nikon

So for example:  AF-S Nikkor 18-105mm 3.5-5.6 G ED

AF-S: Autofocus Silent: Focusing is driven by a “Silent Wave” motor in the lens instead of the focus drive motor in the camera. AF-S lenses focus faster than standard AF-Nikkors and almost completely silently. AF-S lenses with a “II” designation weigh less and are generally smaller than their equivalent predecessors.

18-105 mm is the focal length, you will find a variety of different zooms, for example 18-55,mm or 55.200mm etc.,  there are lenses that are zoom and some are prime lenses, prime lenses will only have one number before the mm, for example 50 mm. This is for all lens makes.


3.5-5.6: this will also depend on the lens, but it refers to aperture, so at 18mm the widest aperture is 3.5 and at 105 mm the widest aperture is 5.6, there are lenses that have a widest aperture of 2.8 throughout the zoom, these are expensive lenses. This is for all lens makes.

G: The lens has no aperture control ring and is designed to be used with cameras that allow setting the aperture from the camera body. G lenses also provide Distance information to the camera.

ED: Extra-Low Dispersion glass: High-quality glass that corrects for chromatic aberration, a type of image and color distortion that occurs when light rays of varying wavelengths pass through optical glass and don’t converge or focus at the same point. Nikkor lenses with ED glass deliver superior sharpness and contrast, even at maximum aperture. Super ED glass is a new type that is used together with ED glass in some lenses to achieve an even higher degree of freedom from chromatic aberration.

VR – “Vibration reduction”

DX: The lens is specifically designed for use on Nikon digital SLR cameras. It produces a smaller image circle for more efficient coverage of the imaging sensor in these cameras, which is smaller than the 35mm film frame.

M/A: A focusing mode on some AF-Nikkor lenses which allows switching from automatic to manual focusing with virtually no lag time by simply turning the focusing ring on the lens.

Canon

Canon IS stands for ‘Image Stabilisation’. Lenses with Image Stabilisation allow you take handheld images at slower shutter speeds without camera shake blurring the image.

A Canon EF-S lens is designed for EOS digital SLRs with an APS-C sized sensor. EF-S lenses are a subset of the Canon EF mount. The S in EF-S stands for ‘short back focus’, referring to the distance between the rear element of the lens and the sensor is shorter. EF-S allows lighter, smaller lens designs that cost less to be produced. EF-S lenses are not suitable for full-frame EOS digital SLRs and mounting the lens may cause serious damage to the camera.

Canon L-series lenses are top-end, professional Canon lenses. L-series lenses are sometimes dubbed ‘Luxury’ lenses. The ‘L’ moniker is reserved for professional Canon lenses, which tend to have extra weather sealing, a constant maximum aperture and superior optical performance. You can spot many L-series lenses thanks to the distinctive red ring around the lens barrel. L-series lenses include a lens hood (to reduce the chance of unwanted flare and protect the front element) and a lens pouch.

The USM label means the lens features an Ultrasonic Motor Drive. Canon USM lenses allow quick, accurate autofocus, which also produces less noise than traditional autofocus systems. There are two types of USM found in Canon lenses: Ring-type USM (premium) and micro-motor USM (value). Ring-type USM has the advantage of full-time manual focus, which allows you to adjust the focus manually without switching between AF and MF modes.

DO stands for diffractive optics, a special glass designed to reduce chromatic aberration and allow a shorter lens design. You can spot a Canon DO lens thanks to the thin green ring around the lens barrel.

Sigma

Sigma DC lenses are designed for digital SLRs with ‘cropped’ sensors. Cropped sensors are smaller than traditional 35mm film or full-frame sensors. Sigma DC lenses are suitable for cameras with APS-C size or cropped sensors that need a smaller image circle to cover the sensor, compared to conventional lenses.

Sigma DG designates the lens is designed for use with digital SLRs but can still be used with 35mm film SLRs. Sigma DG lenses are suitable for cameras with full-frame or cropped sensors.

OS designates the lens has Optical Stabilisation built-in. Sigma OS lenses compensate for camera shake which can blur images at slow shutter speeds or whilst hand-holding telephoto lenses.

HSM stands for Hyper-Sonic Motor, a type of autofocus motor that provides fast, accurate autofocus whilst making less noise than traditional autofocus.

Sigma EX denotes greater optical quality and superior build quality. Sigma EX lenses used to have a distinctive crinkle finish, but this has recently been replaced with a matte black finish.

Tamron

Tamron VC lenses are designed reduce image blur from camera shake. The Tamron Vibration Control (VC) technology corrects for camera shake at 4000 times per second, for a smooth stabilized view in both the viewfinder and your image. The VC system also allows you to pan without changing any settings.

Tamron PZD stands for Piezo Drive, a form of ultrasonic autofocus. Tamron PZD lenses offer you fast but silent autofocus, in a more compact lens size than traditional ultrasonic autofocus motors.

Tamron USD stands for ultrasonic drive, used for fast and smooth autofocus. Tamron USD lenses use deflective traveling waves to drive a rotor, moving elements within the lens to focus your image.

Tamron XR denotes the lens has extra-refractive glass, allowing Tamron to make the lens barrel shorter whilst retaining the same optical quality.

Tamron Di II lenses are designed for digital SLRs with ‘cropped’ sensors. Tamron Di II lenses are specifically designed for cameras with APS-C size sensors, whereas the Tamron Di series (without ‘II’) are compatible with full frame and APC-S digital SLRs.

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Macro Photography on the Cheap

All lenses have a limit on how close they can focus. This is because as objects move closer to the lens, the focal point moves further back, eventually beyond the plane of the film or sensor. An obvious way around this problem is to move the lens further away from the camera. That’s what macro extension tubes do.

For those who cannot afford a dedicated macro lens there are other options, just as good, but that require a little patience, for macro photography.

Extension Tubes or a Reverse lens ring.

The macro extension tubes that I use are very cheap and simple. As you can see from the second photo, it comes in five sections. At each end is a bayonet ring for mounting the tube to the lens and camera body (in this case Nikon). In between those any combination of three threaded tubes of varying length can be used to change the extension by varying degrees. That’s all there is to these tubes, nothing more.

Pros and cons

Here’s the costs/benefits of tubes like mine:

-You need to manual focus, my moving the lens/camera closer or nearer to the object, the same result is achieved by moving the object you are taking a photo of.

-You have no auto control on the camera, you need to put it in Manual to be able to take any photos. You have no aperture on some lenses, the 50mm on the other hand is great for macros as it allows you to change the aperture manually on the lens.

-You could overtighten the threads on the extension tubes making them difficult to unscrew.

-You need to be careful with the lens on a tripod as the centre of gravity changes putting greater stress on the cameras body´s lens mount.

-You need plenty of light. As the objects are closer to the lens, the light is blocked by the lens, so you need a side, overhead, backlighting source of light. Not a problem in a studio of course.

-As there is no data connection between the camera and the lens so the EXIF data will not be complete.

Strengths

-Photographic opportunities otherwise unavailable (without very expensive specialist lenses) are possible.

-Economical.  I got mine from Amazon.com

http://www.amazon.com/Fotodiox-Nikon-Extension-Extreme-Close-up/dp/B003Y5T464/ref=sr_1_4?ie=UTF8&qid=1315346126&sr=8-4

– They have them for various makes of camera. There are others that cost more. Kenko for example.

-A light and compact addition to your gear. I carry mine with me everywhere.

-Useful even with telephoto lenses. A long lens is great for making things bigger, but they can’t focus very close at all. An extension tube can allow you to enlarge with the telephoto but still maintain a good working distance.

-Mechanically simple. There’s not much that can go wrong with these.

-They’ll get you thinking about new ways to take photos. Extension tubes make your lenses a whole lot more flexible, and don’t just have to be for photos of insects or flowers.

A macro reverse ring.

You need to make sure to buy one the correct size for your lens. I have two one for 67mm and one for 52mm.

The reverse ring focuses closer than the extension tubes. And they work like this:

Take the lens off the camera, place the reverse ring onto the camera in the same way as you would attach a lens, turn the lens around, back to front and attach to the reverse ring. You attach the side that the filter goes.

The strengths and weaknesses match above, but with the lens in the reverse position you need to take care of the electronics of the lens against damage.

http://www.amazon.com/Fotodiox-Filter-Thread-Reverse-Adapter/dp/B001G4NBSC/ref=sr_1_1?s=electronics&ie=UTF8&qid=1315345853&sr=1-1

A tripod is highly recommended.

The extensions tubes and reverse ring have opened up a whole new world for my photography without the expensive of a dedicated macro lens. They are great fun.