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Thread: what does all this means?

  1. #1

    Default what does all this means?

    Hi guys me newbie what does all that on a lense means?? like canon 70-200mm f2.8 L USM

    me know only the 70-200 is the distance it can zoom.
    USM is ultra sonic movement??
    the rest all i dont know..

    then also the Sigma 70-200mm f2.8 APO EX HSM

    what all that means??
    and the differnet?

  2. #2

    Default Re: what does all this means?

    F2.8 refers to the apperture.
    APO= lens has been made using special low-dispersion glass, minimize color aberration
    EX, meaning the exterior of the lense is specially finished and being better in quality
    HSM, means Hyper Sonic Motor, which gives a quiet and faster AF.

  3. #3
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    Default Re: what does all this means?

    USM - ultrasonic motor. It is Canon's AF technology that helps to achieve fast and precise autofocusing, usually with low noise.

    APO - Apochromatic. Usually when a lens focus light to a point, different wavelength of light may focus differently, causing colour casts. Apochromatic lenses are supposed to have corrected the misfocusing of all wavelength of light.

    HSM - hypersonic motor. Similar to Canon, just that it belongs to Sigma lenses.

    Ex - Refers to the pro-class lenses for Sigma, just like L refers to pro lenses of Canon.

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    Default Re: what does all this means?

    quoted from someone about L lens from a canon forum. lol..

    If you haven't touch this lens before, don't ever touch it. L means L'cohol. It makes you a L'coholic, and will starts from Love of it , to Lust for more of it. And may increase your Liability, Lie to your spouse and Laughing at others without one. Thats Life with Canon L lenses. Enjoy...

    quoted from http://www.luminous-landscape.com/ about terms found on canon lenses
    Loads of photography tutorials can be found in this site

    EF — This refers to Canon's electronic lens mount, used in all Canon camera since 1987. The previous mechanical lens mount carried the letters FD.

    28 - 70mm — this is the range of focal lengths covered by the lens, 28mm at the wide end and 70mm at the long end (for example).

    f/3.5-5.6 — this is the range of the maximum aperture of the lens, in this example f/3.5 at the lens' wide angle setting, changing to f/5.6 at its longest focal length. A prime or zoom lens with a fixed maximum aperture will have just a single F stop shown in the name.

    L — Canon's designation for their top-of-the-line lenses is the letter L. These lenses are the best that the company knows how to make at any given focal length and aperture, and of course for a given price (which in the case of L series lenses is usually high).

    DO — stands for Diffractive Optic and is used on Canon lenses which utilize a unique diffraction grating to control chromatic aberration and reduce lens size and weight.

    IS — indicates that the lens utilizes Image Stabilization, which reduces vibration as much as 3 stops, allowing hand holding of long lenses at much lower shutter speeds than would otherwise be possible.

    USM — stands for Ultrasonic Motor, a technology that uses sound waves to position the lens elements when focusing. This reduces size, weight and power consumption of the autofocus mechanism as well as increasing speed and allowing for manual override.
    Last edited by slardar; 16th October 2007 at 09:35 PM.
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    Default Re: what does all this means?

    Now you know what the features mean, here's the "benefit"....

    F/2.8 = Aperture opens really large so that you can take shots in lower lighting conditions w/o upping your ISO or slowing your shutter too much.

    USM = Focusing is fast and quiet so that you won't face too much annoying "hunting" of the lens before locking on. This coupled with a F/2.8 or bigger apeture allows your camera to lock on focus faster and more accurately. The quiet-ness is subjective and I won't put too much on this.

    "L" = Aside from the higher price, your lens is the closest you can come to getting the least amount of unwanted interference to make your pictures sharper, if all else remains equal. Some come with a "weather seal" to resist rain and dust.

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    Default Re: what does all this means?

    Quote Originally Posted by deanz4 View Post
    Hi guys me newbie what does all that on a lense means?? like canon 70-200mm f2.8 L USM

    me know only the 70-200 is the distance it can zoom.
    USM is ultra sonic movement??
    the rest all i dont know..

    then also the Sigma 70-200mm f2.8 APO EX HSM

    what all that means??
    and the differnet?
    70-200 - focal zoom length, the bigger the number the closer you get to the subject.
    f2.8 - maximum aperture (determines the speed of your lens, f4 -slow, 2.8 fast, 1.4 faster, 1.0 fastest)
    USM - expensive, need more money
    L - laggi more expensive, need even more money.

    similarly for sigma...

    APO - another pricey option
    HSM - have some more money
    EX - expensive, expensive, expensive

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  7. #7

    Default Re: what does all this means?

    another newbie question..

    how about wide angle lenses? how do we know its a wide angle lens?
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    Member patch17's Avatar
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    Default Re: what does all this means?

    Quote Originally Posted by reaper3075 View Post
    another newbie question..

    how about wide angle lenses? how do we know its a wide angle lens?
    the standard focal length for a lens is 50mm (the idea is that this focal length gives the closest view to what your eyes perceive. some people actually think it's closer to 40/45mm, but i digress.)

    anything below 50 is considered wide angle. e.g. 35mm, 28mm, 24mm are typical wide angle lenses. you can go as low as 20mm, then you start touching on the fish eyes... 15mm, 14mm, 10mm, etc.
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  9. #9

    Default Re: what does all this means?

    Quote Originally Posted by patch17 View Post
    the standard focal length for a lens is 50mm (the idea is that this focal length gives the closest view to what your eyes perceive. some people actually think it's closer to 40/45mm, but i digress.)

    anything below 50 is considered wide angle. e.g. 35mm, 28mm, 24mm are typical wide angle lenses. you can go as low as 20mm, then you start touching on the fish eyes... 15mm, 14mm, 10mm, etc.
    wide angle lenses go past 20, even up to 10 without being fisheyes

    dont get it wrong abt the standard focal length, its a little confusing since digital came in and they started making 1.5, 1.33 and 1.6 crop cameras. 50mm on say a 1.5x crop sensor is actually abt 33mm in terms of focal length, but angle of view remains similar (correct me if im wrong) and some other things like minimum focusing distance and max aperture

    sry abt the second part if im wrong

  10. #10

    Default Re: what does all this means?

    from wat i noe, the L represents Luxury lens. as in, high end?
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