Comparing Lenses & Telecoverters & Cameras

Discussion in 'Canon Lenses' started by photoflyer, Oct 7, 2018.

  1. photoflyer

    photoflyer TPF Supporters Supporting Member

    Joined:
    Nov 15, 2017
    Messages:
    451
    Likes Received:
    647
    Location:
    Washington D.C. Area
    Can others edit my Photos:
    Photos OK to edit
    I am curious what everyone thinks about these combinations of lenses, teleconverters and cameras.

    I just rounded out my collection of lenses with a Canon EF 300 mm F4 USM (used). I already had the 70 -200 mm IS 2.8 version 2 USM.

    In addition I have the 2X version III and 1.4X version II teleconverters.

    Finally I have a 6D Mark II and T7i.

    The link below will take you to a cloud drive that shows all 12 combinations. These were shot at maximum aperture and an ISO of 800. They were shot on a tripod with image stabilization turned off. Also, they were shot with a 2 second shutter delay to minimize camera shake.

    The file name indicates what was used. Files that start with a D were shot on the 6D Mark II. Files that start with a T were shot on the T7i. Next in the file name is the lens and following the dash is which teleconverter if any, was used.

    Do any of these stand out to any of you as being more or less sharp? I already understand the tradeoffs with teleconverters but feel free to comment on anything...it is a forum and we are all here to learn from one another.

    My Cloud

    My Cloud


     
  2. Derrel

    Derrel Mr. Rain Cloud

    Joined:
    Jul 23, 2009
    Messages:
    44,817
    Likes Received:
    17,033
    Location:
    USA
    Can others edit my Photos:
    Photos OK to edit
    I clicked through a few. The biggest problem is the test target: it's perfect for a TC + lens shot...a FLAT-plane target,located in the center of the field of view, with basically nothing important at the edges of the frame, and at vastly different distance than the central target. A good example would be, from nature, a goose on a pond, centered in the middle of the frame. If the TC unit has wonky corner performance, it will not show up too much. Same with the street signs and the stop sign: I looked at six or so pics, all looked "acceptable".

    If you want to evaluate these better, you need a different kind of test subject, one that has the same distance at the center as the edges, and which will show performance from center to corners.

    For some types of shots, like this one test scenario for example, any of the lens +TC pairs is adequate.
     
  3. photoflyer

    photoflyer TPF Supporters Supporting Member

    Joined:
    Nov 15, 2017
    Messages:
    451
    Likes Received:
    647
    Location:
    Washington D.C. Area
    Can others edit my Photos:
    Photos OK to edit
    Good feedback. Thanks. I am still working on getting that duck to hold still!!!
     
  4. Overread

    Overread has a hat around here somewhere Staff Member Supporting Member

    Joined:
    May 1, 2008
    Messages:
    24,740
    Likes Received:
    4,489
    Location:
    UK - England
    Can others edit my Photos:
    Photos OK to edit


    Brick Walls.

    You can shoot them flat on to show curvature and edge sharpness; you can shoot them at a 45 degree angle so that you can compare both depths of field and 100% ensure that you've got the sharp band in the shot (with straight on shots there's always a risk - esp at wider apertures - that any error in the focus could give misleading results)
     
    • Like Like x 1

Share This Page