Teleconvertors and DOF

Discussion in 'This or That?' started by Phocal, Aug 7, 2015.

  1. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    Ok, so this questions has bugged me for a long a time and I figured it is about time to ask it. I have the Oly 4/3 150mm ƒ2 and with the EC-20 it is now a 300mm ƒ4. If I shoot a bird with the lens wide-open at ƒ4 and my friend standing next to me photographs the same bird with his Oly 4/3 300mm ƒ2.8 but at ƒ4, will the photos have the same DOF?
  2. barry13

    barry13 Super Moderator

    Mar 7, 2014
    Southern California
    Real Name:
    As would the forthcoming m.ZD 300/4.

  3. tkbslc

    tkbslc Mu-43 Hall of Famer

    The lens is a 300mm lens now and the aperture is still 150/2 = 75mm wide. 300/75 = 4, so it's an f4 at 300mm. All DOF and whatever calculations apply as if it was a native 300mm f4.
  4. VooDoo64

    VooDoo64 Mu-43 Veteran

    Jul 17, 2010
    Zagreb - Croatia
    Real Name:
    Davor Vojvoda
    only thing why you can get better DOF with TC is because you can come closer with 150 lens ( min.dist ) thats why 40-150PRO have so good DOF on some picture ( it have min dist. 70cm )