When everyone started using DSLR lenses, I felt a little confused: What does the name Canon EF 70-200mm f / 4.0 L IS USM mean? What is Nikon DX AF-S NIKKOR 18-55mm 1: 3.5-5.6 GII ED? This series of abbreviations is like “alien text” to a novice. Today we take some lens labels from three manufacturers, Canon, Nikon and Sony as examples to tell you the meaning and usefulness of these English abbreviations.
Speaking of our Kit Lens
Kit Lens is often our first lens, but how much do we know about them? Let’s take a look, Canon 550D, Nikon D90 and Sony α 550, these three very popular “newbie’s first lenses”, which technologies are included in their Kit Lens?
Canon EF-S 18-55mm f/3.5-5.6 IS
This lens and this focal length (18-55mm) have always been standard equipment for Canon entry machines. From the name, we can already get some information:
After the brand name Canon, we first saw this short name-EF-S. What does this mean? Actually, there are two kinds of lenses in Canon today, one is EF and the other is EF-S. EF corresponds to the Full Frame, while the EF-S lens corresponds to the APS-C format sensor body. In other words, EF-S is a lens for lower-order bodies such as Canon 550D, while EF is a lens for full-frame high-end machines such as 5D mark II. EF format lenses can be used in APS-C format sensor body bodies, but full-frame bodies cannot use EF-S format lenses. This point needs attention when buying!
* Why can’t EF-S format lenses be used in full-frame format (reference)? Because the EF-S format has a thinner imaging circle, it is impossible to make the full-frame photosensitive element that is half larger than the APS-C format fully photosensitive, and it will cause quite strong black corners if it is barely used.
- 18-55 mm
This data is the focal length of the lens (that is, it can be Zoom Far or Zoom Close). 18 (mm) represents the widest end of this lens, and 55 (mm) represents the most telephoto end of this lens. In fact, when you use this data in 400D, 550D and other APS-C format machines, you need to multiply the focal length marked on the lens by 1.6 (Canon body) to be the “usable” focal length for the 550D. Therefore, the 18-55mm mark on Canon’s APS-C format represents a usable focal length of approximately 28mm-88mm. [Here is the opinion of Brother dd6dd7.] If you see a picture on a full-frame 18mm lens, you only see the middle part of the picture when the lens is inserted into the APS-C machine. To see only the middle part of the picture in a full-frame camera, we found that we need a full-frame 28mm lens, so the 18mm lens + APS-C body can see the full-frame body + 28mm lens See the image.
This data refers to the maximum aperture available for the lens at different focal lengths (note that the aperture range is not available, and novices most often misunderstand). In fact, the aperture value is not only determined by the physical size of the aperture, but also the lens length, aperture, amount of light, and loss of light caused by the lens combination. Therefore, when zooming, the aperture value naturally changes. f / 3.5 refers to the maximum aperture of the lens at the widest end (18mm), while f / 5.6 refers to the maximum aperture of the lens at the farthest end (55mm). Of course, the “widest angle” and “farthest end” will vary depending on the lens.
This is the anti-shock technology developed by Canon. Use the floating lens group in the lens, plus a built-in CPU, to compensate for the optical axis shift caused by hand shake. The EF-S 18-55mm f / 3.5-5.6 IS uses a miniature structure. The traditional anti-vibration system for higher-level lenses is simple, but still has four levels of anti-vibration.
Other models …
- Aspheric mirror
The Canon EF-S 18-55mm f / 3.5-5.6 IS is equipped with a piece of aspheric mirror (Related Articles). This is a lens that can correct imaging errors, especially to improve the problem of edge aberrations and blurred imaging.
- DC motor
The Canon EF-S 18-55mm f / 3.5-5.6 IS uses a DC motor instead of the USM adopted by most lenses . In contrast, the USM (ultrasonic motor) is faster and quieter. And this lens will rotate the front end of the lens body when focusing, which may cause inconvenience to use CPL polarizer or star lens.
Nikon AF-S DX NIKKOR 18-105mm F3.5-5.6G ED VR
This lens is one of Nikon’s very popular entry units, the Kit Lens of the D90. This lens uses a variety of Nikon expertise, let’s explore it too.
Although Nikon’s AF-S and Canon’s EF-S are similar in name, they are actually completely different things. The Nikon AF-S is representative of the lens means loaded Silent Wave Motor, an optical focusing Traveling Waves, powered by, quietly and with high accuracy can quickly focus. And it can focus manually all the time. Even when Auto-focus is turned on, you can still manually turn the focus ring at the same time without damaging the lens.
Nikon’s DX format has the same meaning as Canon’s EF-S format. It is a lens developed by NIKKOR for APS-C sensor format cameras. Similarly, if the DX format lens is used in a full-frame body, there will be black corners.
Nikkor is a brand that Nikon specializes in producing lenses. Nikon has multiple sub-brands and specially classified brands throughout history. NIkkor is a brand created by Nikon in 1932 specifically for Nikon F-MOUNT. Today, most Nikon lenses are branded with Nikkor.
The same reasoning as above will not be explained any more. But one thing worth noting is that the magnification of the Nikon APS-C format is the indicated focal length multiplied by 1.5, which is not the same as the Canon multiplied by 1.6. Therefore, 18-105 mm for D90 is approximately equal to 27-158 mm.
The reason is the same as above, so I won’t explain much.
The G lens is a new model design from Nikon. There are two biggest differences between this lens and the previous D-type lens: (1) No aperture ring -In the film era, the aperture value can be manually adjusted from the lens, but now most of the aperture value is set in the body. , So the aperture ring of the lens body is eliminated to reduce weight and cost. (2) Support new technology 3D matrix metering -this new technology can achieve more accurate metering effect.
ED stands for Extra-low Dispersion lens . This technology was developed by Nikon to reduce the dispersion caused by the light lines in the lens. The so-called dispersion refers to an error in which the lens cannot completely restore the color of light. Adding low-dispersion ED lenses can help improve this error.
VR is short for Nikon’s anti-shock technology. Like Canon’s IS system, it effectively prevents the blur caused by hand shake. The structures of the two are similar, but different algorithms are used.
Other models …
- Aspheric mirror
Nikon AF-S DX NIKKOR 18-105mm F3.5-5.6G ED VR also has a piece of aspheric mirror, which we can also know from the words Aspheric on the bottom of the lens body .
Internal focusing technology refers to focusing by the floating lens group inside the lens. The lens barrel does not rotate during focusing, which is quiet and fast. It is very convenient to use CPL polarizers or star mirrors.
SWM, Silent Wave Motor, has been explained above when talking about AF-S, and will not be described in detail here.
Sony α SAL-1855/DT 18-55mm f/3.5-5.6
This lens is the Kit Lens of Sony α 550 (A550). The basic data is very similar to the Canon EF-S 18-55mm f / 3.5-5.6 IS of the Canon 550D, and many technologies have been explained above. Let’s take a look at the special standards that belong to this mirror. Right.
Sony’s alpha series adapter can be used on the alpha series body. In fact, Sony inherits Minolta, a well-known camera maker, so all Minolta AF lenses can be used on Sony bodies except Sony’s mirrors.
Sony’s DT and Canon’s EF-S and Nikon’s DX are lenses specially developed for the APS-C format SLR. Black corners will appear on full-frame bodies. Sony’s magnification is 1.5 times the same as Nikon. The data of 18-55mm is actually 27-82.5mm on the fuselage.
Other models …
Sony Motorcycles for Low and Medium Lenses
- Two aspheric mirrors and one ED mirror
The Sony lens also uses aspheric and ED lenses, which have been explained above and will not be described in detail.
- Why is there no shock protection?
This is because Sony uses the body anti-vibration technology , which can obtain the anti-vibration effect regardless of the body of any mirror, so the lens body does not need to adopt the anti-vibration technology.
Other common tags …
- AF / MF A / M
The lens body has this button, which means that the focus mode can be switched, A for autofocus, and M for manual focus.
This symbol refers to the size of the filter. The number next to the symbol is the size. Buying UV, CPL and other filters depends on this size.
Today we briefly introduced the tags of each Kit Lens. Rest assured, we will continue to analyze the lens with you! See you next time in episodes two and three!