A little confused

Discussion in 'Photography Beginners' Forum' started by Tighearnach, Jan 14, 2008.

  1. Tighearnach

    Tighearnach TPF Noob!

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    Hello.

    I am just trying to get something clear in my head:confused:.

    I have a 300mm lens and im thinking of buying a 1.4X converter. I use a cropped sensor camera (400D).

    So am i right in saying that i will have a magnification of 420mm but my field of view (if thats what i shud call it?) will be 672mm or thereabouts? Or am i way off here....?

    Thanks again
    T
     
  2. Shibby!

    Shibby! TPF Noob!

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    You sir, are correct..

    In equal's to full frame focal lengths, you will have 672 mm of zoom, however, put that on a full frame digital camera, and you'll be back at 420mm with the 1.4 TC.
     
  3. Happy Hour

    Happy Hour TPF Noob!

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    don't forget you almost double you F stop with a tele converter.I use my 2x all the time but on a 300mm lens full zoom its at a f11 as the widest aperture i can go.
     
  4. Helen B

    Helen B TPF Noob!

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    The F-number gets multiplied by the same factor as the focal length, so a 1.4x teleconverter results in a one-stop increase in the F-number (eg f/4 to f/5.6) and a 2x teleconverter results in a doubling of the F-number, or a two-stop increase in F-number. This only applies to the type used behind the main lens. Teleconverters used in front of the main lens should not affect the F-number.

    Best,
    Helen
     

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