DSLR lens designations for Canon/Nikon?
I'm very new to the DSLR business. I want a 100mm Macro lens for closeup dental shots. It must have the option to change from manual to auto focus. Must have a large depth and field of view. What body reasonably works, and what about the lens designations themselves. I'm a total ignorant and please spare no details.
For example, EF 100mm f/2.8 Macro USM
^ I know 100mm but what is f/2.8? USM? EF?
You've picked a great lens.
EF is the name of Canon's current lens mount. It stands for "Electronic Focus" (that was something to brag about when it came out in the 80s)
f/2.8 is the maximum aperture the lens can open up to. The aperture is the size of the hole in the lens that lets in light.f/2.8 is considered wide; it will let in lots of light allowing for a short shutter speed, which minimizes motion blur in your photo,
USM stands for UltraSonic Motor. This is Canon's quietest, fastest, most accurate autofocus. It does a great job (I own this lens).
Any lens can toggle between manual and autofocus with the simple flick of a switch located on the lens barrel.
100 mm is the focal length of the lens measured from the center of the lens to the focal plane of the camera where the film or sensor is. The f/2.8 is a ration of the length of the lens divided by the largest possible opening of the lens. There's an adjustable diaphragm in the lens that restricts the amount of light commonly referred to as an aperture. Set to its widest setting the lens in you example must have an opening of a little over 35mm. 100/35=2.8 The larger the opening the more light reaches the sensor. To get your depth of field you need to close the lens to a smaller aperture. For example f/8.0 or f/16 closes the lens down and provides a greater depth of field.
USM is Canon's patented Ultra-Sonic Motor. It focuses faster and quieter with less movement than there other lenses.
EF refers to Electronic Focus again a Canon designation to distinguish between there older manual Focus lenses and there lenses designed for the EOS system which was introduced in 1987.
If you are buying this lens you must purchase a Canon EOS camera body. For your described purpose any of their current Camera bodies should work fine. I do recommend getting one with live view so you can see the image on the LCD screen. I own a T3i and am quite satisfied with the camera. They make many others that are quite good. Other brands such as Nikon are also fantastic but you could not use them with the lens you described.
EF is the type of mount the lens uses, EF is what Canons use so that lens will not work on a Nikon.
F/2.8 is the maximum aperture, a lower number allows more light in and gives a more shallow depth of field. The F-stop is measured relative to the focal length.
Aperture diameter X F-stop = Focal length.
So on this lens, the aperture is 35.7mm
The aperture can be made smaller just with settings in the camera, you may want to "stop it down" as we call it to keep more of the mouth in focus.
USM is Ultra-Sonic Motor, which means fast and quiet focusing.
I'm a Canon shooter myself and that's what I recommend because I find them more intuitive.
If your just shooting stills, Nikon and Canon are of very equal quality (though many people would fight to the death over this issue)
If you do get a Nikon, you'll have to find a different lens
http://www.bhphotovideo.com/..._M100.html
That would be the closest, not as high quality as the Canon L lens