TC Questions

Discussion in 'Nikon' started by bikealps, Aug 5, 2011.

  1. I just got a TC-17EII teleconverter.
    The manual has a list of compatible lenses. My 70-200 f2.8 AF-S VR2 is on the list. My other lenses are not.
    I understand that:
    1. if used with an incompatible lens, the elements of the TC and the lens could touch and damage both
    2. screwdrive lenses (AF, not AF-S) may not AF
    3. non-CPU lenses (AI, I don't have any of these) won't report focal length correctly
    To confirm my understanding, I should not use the TC with any of my shorter lenses, such as 16-36 f4 AF-S, 24-70 f2.8 AF-S, 50 f1.4 AF-S G, etc., right? Besides, there is no point in using a TC with such lenses.
    What about my screwdrive 105 f2.8 AF micro? Conceivably that would be a useful combo. Will it work? Is it safe?
     
  2. ShunCheung

    ShunCheung Administrator

    Those TC-nnE teleconverters are only compatible with AF-S lenses (including the older AF-I lenses in this context). You cannot mount screwdriver AF/AF-D lenses on them unless you file of the extra tab.
    Additionally, I would only use those TC-nnE on 70-200mm/f2.8 AF-S or 80-200mm/f2.8 AF-S lenses and bigger ones, including 200mm/f2, 300mm/f2.8, 200-400mm/f4 AF-S and up.
     

    1. 2. screwdrive lenses (AF, not AF-S) may not AF
    There is no "may" about it. They won't autofocus, period. :)
    But as Shun noted above, they won't even mount on an AF or AF-D lens unless modified. In which case they still will not autofocus. Just to be clear, there is no "autofocus" mechanism per se in the autofocus TC-xxE series converters. They just pass through the electrical signals from the camera to the AF-S/AF-I motor in the lens to control the autofocus. Since AF/AF-D lenses have no internal autofocus motor, they can't autofocus if a modified converter is attached. TC-xxE converters do not have a "drive shaft" to turn the mechanical autofocus gearing of an AF/AF-D lens.
    -
    3. non-CPU lenses (AI, I don't have any of these) won't report focal length correctly
    Again, they can not be mounted unless the converter is modified. And if modified to fit, they obviously will not report focal length correctly, as there is no CPU in the lens to report it.
     
  3. The VRII lens is newer than the TC, so that is the reason it is not on the list. Why should you use a TC on 16-36 if you have 24-70?
     
  4. Just to add: I would not be afraid of filing off the tab on the TC-17 and trying it, at least on the micro lens (which is the case which would most obviously benefit). It's a relatively easy modification - I did this to use a TC-14E on my 500mm f/4 AI-p - although I'd look in the back of your lens first and make sure it'll clear it. I'd not even consider trying it on your wider lenses; even if it didn't clash physically, the optics of the teleconverter are designed to work best with longer lenses, so I doubt you'll like the results. The micro lens may also suffer optically, but possibly by little enough that it's still useful. Filing the tab off may reduce the resale value, but otherwise it's a harmless change. Some third party teleconverters are less picky about what they mate to (in part because they don't extend inside the lens) and can autofocus with screw-focus lenses, if you need more flexibility.
     
  5. ShunCheung

    ShunCheung Administrator

    There is definitely not enough clearance on the rear end of the 105mm/f2.8 AF/AF-D (screwdriver type AF, not AF-S) to mount any TC-nnE, and there is no point to use the 16-35 or 24-70 with it.
    On some AF-S zooms, you can mount TC-nnE teleconverters when they are zoom to the long end, but if you zoom it to the wide end with the TC on, the lens elements may collide. My advice is not to risk anything like that. Those TCs are designed for fast and long teles.
     
  6. cool, guys. Thanks. I'll use it with the 70-200 VR2 only. When I win the lotto, I'll use it with a 400 f2.8 as well.
     
  7. Thanks, Shun - I'd seen discussion about using teleconverters with the 105mm AF-S VR before, so I carelessly assumed that there may have been clearance; apologies for the bad advice.

    Allan - can I have one too? :)
     
  8. ShunCheung

    ShunCheung Administrator

    I happen to have both a 105mm/f2.8 AF (bought that back in 1990, therefore pre-D, which started in 1992, with screwdriver AF) as well as a 105mm/f2.8 AF-S VR. It is the earlier screwdriver AF version that has insufficient clearance on the rear end for those TC-nnE teleconverters (even though you remove the tab on the TC front mount).
    You can see the recent thread on mounting the TC-20E III onto the 24-120mm/f4 AF-S VR. While that is possible with the lens zoom to the 120mm end, you can potentially damage it if you zoom back to the 24mm end with the TC mounted: http://www.photo.net/nikon-camera-forum/00YzqI
    Bottomline: I'd say only use those TCs on long teles.
     
  9. Thanks for all the info. I agree, it only makes sense on the 70-200 and longer lenses.
    I just wanted to make sure I knew the rules.
    Agian, you guys rock!
     
  10. Hmmm, you could use a 'filed' TC-nnE on your 105 micro if you slot in an extension tube.... :)
    I've got the 105 f/2.8 AI-s micro - I can fit the TC-20EII on to it if I slot in the PN-11 extension tube between it and the lens. Gives me a maximum of 1:0.44 magnification, with frankly superb image quality. No chromatic aberation that I can see even on high contrast boundaries.
    The below image is a bit rough and ready as it was shot hand held at ISO4000 on a D700 at f/5.6 and 1/25. Equivalent focal length is 210mm. The gap between each mark on the ruler is 2mm, there's roughly 16mm across the width which fills a 36mm sensor edge to edge, so the magnification is 1:0.44 or ~ 2.3:1
    [​IMG]
     

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