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Thread: noob question.from newbie

  1. #1
    Join Date
    Sep 2005

    Default noob question.from newbie

    erm can someone please enlighten me on wat is an extension tube? how does it enable one to shoot macro? and also does the close up filter enable one to do macro shots as well?

    thanxx in advance.

  2. #2

    Default Re: noob question.from newbie

    Both are ways of reducing the minimum focing distance of the lens there by giving better magnification. Extention tubes move the original focal point away form the film/sensor plane while filters make the light rays converge sooner.

    I guess the main advantage with a filter is you dont lose your infinity focus (correct me if i am wrong) but will lose some quality (it is another layer of glass afterall) Extention tubes dont degrade the orignal quality of light coming into the lens but you will lose your infnity focus.

    Hope this helps.
    Furry Photos - Photography for the Modern Pet

  3. #3
    Join Date
    Nov 2003

    Default Re: noob question.from newbie

    cky1504 is correct.. the extension moves the focal point of your lens by physically moving the lens away from the film plane, allowing you to focus closer, and thus increasing the object size and giving you macro capability. No serious image degradation occurs, but sometimes, light falloff might occur. You will lose infinity focus.. in fact, your lens will only be sharp within a very limited range.

    Close up filters come in different strength and construction. The best type of closeup filters are the 2 elements diopters from Nikon (3T, 4T, 5T, 6T), or Canon (250D, 500D). They do optically what the extension tube does, and allow you to focus closer. It's more versatile and easier to apply. Not too sure about the infinity focus when using diopters though... my experience is that you still lose infinity focus.


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