Cross-type focusing points

Discussion in 'Nikon DX DSLR' started by FullFrame, Jul 2, 2008.

  1. The D3/D300/D700 all have 51 focusing points, 15 of which are cross-type. Which ones are they? Can't find anything in the documentation on this.
     
  2. spyder57

    spyder57

    499
    May 26, 2006
    The 15 clustered in the middle. The center 3x5 array.
     
  3. Pardon my ignorance but what is meant by the "cross-type" focus points ... ?
     
  4. KG72

    KG72 Guest

    There are two types of focus sensors in DSLRs. Vertical Line Sensors and Cross-Type Sensors.

    Vertical Line Sensors are one dimensional contrast focus points. They detect and focus on contrast along a vertical line and are generally considered to have a lower accuracy except for when detecting contrast along a vertical line.

    Cross-Type Sensors are two dimensional contrast focus points. They detect and focus on contrast along both a vertical and horizontal line. Thus providing higher accuracy in focus.

    There is a good article on Autofocus and how it works here:

    http://www.cambridgeincolour.com/tutorials/camera-autofocus.htm
     
  5. Thank you for the explanation & the link. It was very informative.
     
  6. Great link! Thanks to all that have replied.