Well this is Strange with the 28-70 f/2.8…

Discussion in 'Lens Lust' started by soxOZ, Aug 19, 2008.

  1. I have been using my Kenko 1.4x TC with a Nikon 80-200 f/2.8D (2-ring) and it works great, but one thing it doesn’t do is show the correct FL combined. So when I use them together the EXIF data shows if it’s only the 80-200 F/2.8 and the setting it uses. If I shot at [email protected]/2.8 with the TC, that is what it shows, and not [email protected]/4 which is what it really is…

    Now that your totally bored, this is what I found when I decide to try the Kenko 1.4x TC with my 28-70 f/2.8. I did a triple check to ensure that there was plenty of clearance between the TC and the rear element of the 28-70 at all FL’s. Can't be too careful here and rush it...
    Now this is the strange part, when I fitted it, the maximum f-stop now was f/4 on the camera which is what it should be with the TC fitted
    , instead of f/2.8. I just took a couple of shots at 70mm f/2.8 (true settings) and the EXIF data show that it was 100mm f/4 and the equivalent Focal length in 35mm film is 150 mm.
    So what extra has the 28-70 f/2.8 got over the 80-200 f/2.8 so that it shows the correct EXIF data when used with the Kenko 1.4x TC…

    If someone knows the answer I would be very interested….

    Here is part of the copy of the EXIF data from one of the shots with that combination…
    __________________________________________________________________
    Camera
    Make:............. NIKON CORPORATION
    Model:............. NIKON D300
    Software:............. Ver.1.03
    Date/time:............. 19-Aug-08 5:36:13 PM
    Lens:............. 28-70 mm
    Max. aperture value:............. f/4 (this shows f/4 instead of f/2.8)
    Focal length:............. 100 mm (This now shows 100mm instead of 70mm)
    Exposure time
    :............. 1/125 s
    F-number:............. f/4
    Focal length in 35mm film:............. 150 mm (Shows the true equivalent in 35mm)
    Exposure program:............. Shutter Priority
    ISO speed ratings:............. ISO 1600
    Exposure bias value:............. 0.00 eV
    Metering mode:............. Spot
    Light source unknown
    Flash Flash did not fire
    Scene capture type:............. Portrait
    Quality:............. RAW
    White balance:............. Auto
    ISO setting:............. ISO 1600
    Focus mode:............. AF-C
    Noise reduction OFF
     
  2. You got it for lens with FL of 70mm fitted with TC 1.4 increase is 40% or 70 x 1.4 = 98mm or nearest, and 100mm is near enough - both in FX and DX. Why one lens display correct EXIF over other is far beyond me, best thing is to query NIKON, i take it there is support organisation in OZ.

    Hope this help.

    Mladen
     
  3. adrianaitken

    adrianaitken Guest

    Probably because the 28-70 is an AFS lens and is more intelligent. Count the number of contacts on the 2 lenses, are there the same number ?
     
  4. This comes from Nikon USA

    AF-S Teleconverters are compatible with AF-S and AF-I NIKKOR lenses except AF-S NIKKOR 14-24mm f/2.8G ED, AF-S Zoom-NIKKOR 17-35mm f/2.8D IF-ED, AF-S NIKKOR 24-70mmf/2.8G ED, AF-S VR Zoom-NIKKOR 24-120mm f/3.5-5.6G IF-ED, AF-S Zoom-NIKKOR 28-70mm f/2.8D IF-ED, AF-S VR Zoom-NIKKOR 70-300mm f/4.5-5.6G IF-ED and DX NIKKOR lenses. (Please note that AF-S Teleconverters are not compatible with AF-NIKKOR lenses).

    And as Adrianaitken stated it may have something to do with differences between AF-S and AF-D lenses. Just a guess.
     
  5. Thanks for your answer guys. I not concerned about this but just thought it interesting that it showed correct reading with one lens and not another.
    I know the Nikon TC's will only work with AF-S lenses, thats why I got the Kenko as it has the screw drive connector between the camera and lens to use with my 80-200 f/2.8.

    But interesting that I also use the Kenko TC with my 50 f/1.8 and this shows only the lens setting on the camera, like the 80-200...
    Both of those are AF-D lenses and it works with the AF-S lens, I don't really know.
    I may try it with one of my other AF-S lens to see what it does...
    I thought that this may be of interest to some who have the Kenko TC's.

    But anyway, it work superbly on my 80-200 f/2.8, and really thats why I got it in the first place, :smile:
    all this other stuff was just for interest and a bit of fun to see what it could do... Thanks again....