Thread: How to calculate wide end of zoom focus (Angenieux 16-42mm)

Reply to Thread
Results 1 to 2 of 2
  1. #1 How to calculate wide end of zoom focus (Angenieux 16-42mm) 
    Senior Member
    Join Date
    Dec 2017
    It appears that on my Angenieux 16-42mm the focus at the 16mm end at about 6 feet and further is infinity. Anything from the mid 20's to 42mm focus is according to the focus scale. I assume this is a normal phenomenon because of the physics of a wide lens. Are there charts to help find out at what focal length infinity begins?
    Reply With Quote  

  2. #2  
    Senior Member Bastian Meier's Avatar
    Join Date
    Apr 2013
    Graz, Austria
    I guess you are talking about the Depth of Field. (DOF)
    DOF Depands on different factors. The Focal length, the aperture, the distance of focus, and the sensor size.

    The bigger the focal length, the smaller the the DOF.
    higher aperture (smaller opening) means bigger DOF.
    the further away the focus is from the Lens, the bigger the DOF is.
    bigger sensor means smaller DOF.

    Of course all this can exactly be calculated.

    There is also the term of hyperfocal, which means that at the given focal length, aperture, from a certain distance on everything is in focus till infinity.
    Reply With Quote  

Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts