TC-14EII Qeustion

Discussion in 'Lens Lust' started by Scorpio1, Aug 25, 2008.

  1. After searching the net for an hour and not finding what I was after, I'm back for help.

    When I add the TC 1.4EII to the 70-200VR my thinking is the the lens becomes a 420mm at f/4 in DX? Or is the aperture smaller at the long end?
     
  2. Hi Ed,

    If the lens aperture is constant through its zoom range, then it will also be constant with a TC on.

    Sean
     
  3. Tim White

    Tim White Guest

    It becomes a 280mm f/4.

    A 300mm lens would become a 420mm with the TC14.
     
  4. Thanks Tim & sean.
     
  5. Secondly how does the IQ compare with 70-200/2.8 plus + TC vs 300/4?
     
  6. eparr

    eparr

    60
    Jul 28, 2007
    S.F. Bay Area
    A 70-200mm in DX would translate to 105-300mm, then add the 1.4x TC and you get ~150-420mm.
     
  7. So basically 280 mm f/4 in DX is equivalent to 420mm f/4 in FF which provides the same FOV. Correct?
     
  8. Tim White

    Tim White Guest

    Not true. The DX sensor crops images, narrows the field of view. It doesn't magnify them.
     
  9. Commodorefirst

    Commodorefirst Admin/Moderator Administrator

    May 1, 2005
    Missouri
    Hi Ed,

    think of the DX system as a built in crop system. It doesn't magnify the image or bring it closer, it reduces the apparent field of view in the viewfinder.

    One advantage the DX does have is it puts more pixels on the subject.

    Your 70-200 in DX puts as many pixels on the subject at the far end as a 150mm lens in FX mode. To get 200 mm and the same number of pixels on the subject in FX mode you would need a longer lens.

    What is nice about FX is the quality of those larger pixels on the sensor, which gives better higher iso, etc. etc.

    so to compare, most folks would say the 70-200 with 1.4 is pretty close to the 300f4, with the prime probably in a lot of cases being sharper a tad wide open, but the 70-200 having VR is a bonus in lower light conditions with slower shutter speeds, plus you can always take of the TC.

    Of course each lens is different and other results may vary. My copy and my friends copy of the 300 f4 were sharper wide open vs both of our 70-200 with 1.4 attached wide open. But for all practical purposes, you were hard pressed to tell the difference.

    One nice thing is the 300 takes the 1.4 and 1.7 TC very very well, and it is a great long range first lens to grab and compliments the 70-200 so well.

    Cheers,

    Wade

    cheers, hope this helps.
     
  10. Wade,

    Thanks for the clear expaination. It was a big help. :smile: