Teleconverter

Discussion in 'Photography 101' started by haunteddoc, Feb 25, 2007.

  1. haunteddoc

    haunteddoc Member

    Ok, stupid question, but what happens to the speed of a telephoto lens, or any lens for that matter, when you add say a 2X teleconverter. Is the speed halved?
     
    Last edited by a moderator: Apr 11, 2014
    haunteddoc, Feb 25, 2007
    #1
  2. Tim

    Tim Administrator Staff Member

    you lose two f/stops worth of exposure. ie. a 2x tele at f/4 is really f/8 for shutter speed. so really your shutter speed is reduced to 1/4 of what it would have been.

    ie. 1/1000sec at f/4 = 1/500sec at f/5.6 = 1/250sec at f/8

    SO....you need a lot of light to use a TC unless it's on a fast lens (ie. f/2.8 or so)
     
    Last edited by a moderator: Apr 11, 2014
    Tim, Feb 25, 2007
    #2
  3. Roger

    Roger Member Staff Member

    And only one stop with a 1.4x.

    Got some great shots this week with the 70-200 + 1.4tc. I have too many to go through right now, so it's going to take some time to get them online.
     
    Last edited by a moderator: Apr 11, 2014
    Roger, Feb 25, 2007
    #3

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