Nikon lenses in general

Comments

• bruto

  January 2016 edited January 2016

  The F stop or aperture is different from the shutter speed. You can control both aperture in the lens and shutter speed in the camera, and they, along with ISO or sensor sensitivity, interact for your total exposure. Open the lens by a certain amount, and you will have to speed up the shutter accordingly.
  
  And yes, the lower the number, the wider (faster) it is. If you want a good explanation of this all, try looking up "exposure triangle" on Google.
  
  If you read the info on the lens itself, the F number will be in the format 1:x, where X is the number you're looking for. An f/1.8 lens will say "1:1.8".
  
  The focal length of a lens determines how wide a view (and thus also how magnified) it gives. The effect will vary with the format of the camera. On a DX format digital camera, 18mm is a wide angle, 35mm is about normal, and over about 50mm is what might be called a short telephoto. 300mm is a considerable telephoto. Shorter than about 16mm would be a super wide angle. A zoom lens will change its focal length over a certain range.
  
  DX means a lens is suitable only for cropped sensor (DX) cameras, such as the D3xxx and D5xxx, and will not perform properly on full frame. An FX or full frame lens will work fine on DX. If neither DX nor FX is mentioned, assume FX for a Nikon lens. Other brands use other terminology.
  
  VR is Vibration reduction, which allows hand holding at slower speeds than normal. The original VR was good for about 3 stops, the newer generation for about 4. You can live without this, but it's very nice to have. The longer the focal length, the more useful it is.
  
  A lens will generally be specified by its focal length and its maximum aperture, with some other features either before or after it. If the focal length is a single number, it means this is a "prime" lens of a single focal length. The maximum aperture will also be a single number. Prime lenses are simpler, generally faster, and require fewer optical compromises than zooms, so although many zooms are fine in quality, primes tend to be fine at a cheaper price.
  
  If the focal length is two numbers, such as 18-55mm, it means this is a zoom lens, and you can vary the width and multiplication factors of the lens. Zooms are very handy, but tend not to be as fast as primes. It's rare to see a zoom faster than f/2.8. Many zooms have a variable aperture, which means the max aperture will also be two numbers, one for the shortest and one for the longest length available. In between, the numbers will be in between. If there is only on F number, the zoom has a constant aperture. Constant aperture zooms tend to cost more.
  
  In addition, when shopping for D3xxx and D5xxx family cameras, one must be sure that the lens in question has its own focusing motor, or you will not get AF. Older AF lenses depend on a motor in the camera, and that is not present.
  
  So, along with the other terminology, we have the following:
  
  AF alone is the oldest AF type, with an aperture ring, and "screwdriver" focusing provided by the camera only.
  
  AFD is similar, but with added electronics for better distance sensing.
  
  AF and AFD lenses are backward compatible to manual cameras.
  
  AFG is similar, but with no aperture ring, aperture adjusted only by the camera, not backward compatible to manual cameras, and only marginally compatible with the first AF film cameras.
  
  All three of these earlier types will meter correctly on the D3xxx and D5xxx cameras, but will not auto focus.
  
  AFS is what you need, with a built in motor. It will always be a "G" type as well, and everything that comes after the original "D" type will be D as well.
  
  Some AFS lenses will specify "SWM" meaning they have a "silent wave motor" that is fancier than the standard sort.
  
  A newer type, "E" has an electronic aperture mechanism, and is not compatible with all early AF cameras, or with any manual cameras, but it is with most of those discussed here.
  
  "ED" will also sometimes appear, and this designates that one or more glass elements are made with a fancy "extra dispersion" glass.
  
  When looking at a lens, be sure you note all its characteristics, and if it does not specify something, assume it is not present.
  
  So, for example, the kit lens on my D3200 is an "18-55mm f/3.5-5.6 G AFS DX". This means that it is suitable only for DX, it has a built in motor, its focal length zooms from 18 to 55 millimeters, its maximum aperture varies as it zooms, from f/3.5 at 18mm to f/5.6 at 55mm, and it is a G lens with no aperture ring. Since it does not say ED or E on it, it does not have any ED glass in it, and it is not an E lens.
  
  I have here the kit lens from an old N65 film camera. It says on it, "AF Nikkor 28-80mm, 1:3.3-5.6 G". this is a screwdriver focusing lens, does not have "D" electronics, and does not have an aperture ring. It will meter on my D3200 but will not auto focus and will not send the most finicky distance details to the meter and flash.
  
  Here's a little help in deciphering the lingo, especially for third party lenses:
  
  (see here)
  
  Manual lenses can be used on the D3xxx and D5xxx cameras in manual mode. They do not operate the meter at all, but will function, often well, if you guess the exposure correctly.
  
• Galan

  January 2017 edited January 2017

  Your photography course should cover all of your questions and some may be test questions (a little chuckle here).
  
  Lenses that have a dash (-) between the numbers 80-200 are what are known as 'zoom' lenses. The others without that dash are considered fixed, that is to say, to compose your shot, you don't zoom the lens, you physically move closer or further away in order to determine what you want in your photo.
  
  The f-stop (seen as f/1.4 for fixed or f/1.4-5.6 for some zoom lenses) indicates the largest aperture or lens opening available for that particular lens. Aperture is the lens' ability to gather light. The lower the number, the faster the lens can produce a properly exposed subject under varied lighting conditions.
  
  As for the DX, VR and other plethora's of indicators, I think @Bruto covered them quite in depth.