Kenko Converters - Which are the good ones?

Discussion in 'Nature' started by marek_m, Jun 17, 2004.

  1. Todays Pro converters from Kenko are highly reputed. There are
    predecessors in a black finish also using a 7-element lens design
    selling for almost nothing.

    Is the optical performance on par with the current offerings?

    I know there are differences regarding AF and metering. I don't care
    about that as I will use the TC with MF Nikkors only.
     
  2. The Kenkos designated "Teleplus PRO" are the good ones. The black and white versions are equal optically, but the white one maintains more CPU functions (AF-S I think).
     
  3. The exact model name is "Kenko Teleplus Pro 300 Teleconverter for Nikon AF-I & AF-D" 1.4x, 2x, and 3x. The key words to look for are "Pro 300".

    I have the 1.4x and 2x and I think they are wonderful. I believe they are compatible with all Nikon autofocus lenses (would someone please correct me if this is not true). I like their stackability too. Once I stacked these two up on the 80-400VR for some moon shots and the results were very good.

    The Nikon TC14E and TCE20E (and the II series) are great too (according to comparison reports the Nikons have a slight edge over the Kenko Pros), but they are only compatible with certain Nikon AFS lenses (longer lenses) and are not stackable. Once I tried to fit the 2x on the 80-400VR (forgetting for a moment that it was only useable on AFS lenses) and got it stuck on the lens! Fortunately I was able to take it off later with no damage on either end.

    Now I am wondering how good the 3x is. I would like to hear from someone who has had experience with it.
     
  4. But if I recall the info on the Kenko website correctly, the PRO teleconverters are recommended/required only for lenses f2.8 or faster.

    Based on that advice I decided to save money and buy the non-PRO version to use with my Nikkor 300/f4 (non-AFS) lens. Shooting test targets and some random scenes (shooting slides, on a tripod, with cable release, moving in/out to achieve equivalent crops, examining slides with a 10x loupe) I was not able to convince myself I was seeing any significant degradation in either contrast or sharpness.

    Given how relatively infrequently I need the extra reach, saving the $100+ and getting miniscule image degradation seemed like a very reasonable tradeoff...

    Larry
     
  5. Larry, the pro Kenko teleconverters supposedly would not autofocus with any lens slower than f/2.8. However, this disclosure does not make a lot of sense, as the 2x already takes away two stops of light. Personally I did not notice this problem -- maybe I just focused manually when the autofocus did not work.
    Anyway, this will not be an issue for Marek, as he intends to use it for manual lenses only. Here are some reviews on a few Kenko models, including the "non-pro" versions.
    http://www.photographyreview.com/35mm+Converters/Kenko/MPL_9345_3132crx.aspx
     
  6. I have all three Kenko Teleplus Pro teleconverters. I have the AF-S (white) versions of the 1.4x and 3x, and the slightly older version (black) of the 2x, which was an excellent ebay buy. I will offer support for the notion that these are excellent products that will not disappoint even very critical photographers. I have found that when I have compared results between the Nikon and Kenko teleconverters (using good teles) I really cannot distinguish the difference. There may be differences in "corner sharpness," but I mainly do bird photography where image corners aren't that important, usually. Someone asked about the 3x Kenko. Here's a sample image using a Nikon D100, Nikon 500mm. f4P, and the Kenko Teleplus Pro 3x teleconverter. Keep in mind you have to raise up the ISO level to 1000 or higher in most situations, and conditions otherwise have to be fairly ideal (no atmospheric interference, no wind, etc.)
    008Zzo-18421584.jpg
     
  7. One correction to my goldfinch photo post. It was taken with a 400mm. f3.5 and the 3x telextender, not with a 500mm. f4.
     
  8. Douglas, that's a pretty sharp image of a small bird coming from a 3x teleconverter. Thanks!
     
  9. High, I recently compared the Kenko MC7 2x vs the 300 Pro 2x.

    I hope to publish the results this weekend, but tin the meantime here are my observations:

    The quality of the 300 Pro series is superior. The slides taken under identical test conditions show that the 300 series produces clearer and sharper images, easily noticable with a 4x loupe on a light table.

    A surprising relevation was that 2x does not always equal 2x. The MC7 image was not magnified to the same extent as the Pro 300 2x was. I may try to do some calculations to see if the MC7 is more like a 1.8 or 1.9x or of the 300 is 2.1x etc.

    No offense to previous posters, but those who arn't seeing a difference in quality are either not looking close enough or have technique or lens quality issues that mask the differences between the two.

    As with most lenses, you get what you pay for, but with diminishing returns. This is to say that teleconverter B that costs double that of teleconverter A will not necessarily be twice as good. But it may be 20% better, give or take.

    I'll post a link soon showing the results of this test. I should mention that it was taken with a 300mm f/4, which autofocused just fine.

    CB
     
  10. Douglas,
    I agree, that is a fantastic goldfinch photo! I do lots of bird photography also and use an older kenko 1.4x af TC with my 400 3.5 nikkor. I like the image quality but often need even more magnification (with a film body). Now I am tempted to get a 2x! How do you meter with a D 100 and an AIS lens? Does adding the TC allow the meter to work?
     
  11. For Chris Browne:
    "No offense to previous posters, but those who arn't seeing a difference in quality are
    either not looking close enough or have technique or lens quality issues that mask the
    differences between the two."

    Possible alternate explanations include:

    -- different prime lenses (some primes work better with particular converters than others
    in an unpredictable way)

    -- sample variance among converters (did you test one example of each model, or
    several?)

    I always wince when person A does a test and person B claims that person A's observations
    can't be correct (having been on the receiving end of such claims before).
     
  12. Richard wrote:
    "I like the image quality but often need even more magnification (with a film body). Now I am tempted to get a 2x! How do you meter with a D 100 and an AIS lens? Does adding the TC allow the meter to work?"

    My bad. I should have added that my 400 f3.5 has been "chipped" by Rolland Elliott, and that's why the metering works. Otherwise, it would not. But you know, the truth is that when a D100 or other DSLR is used, one can quickly and easily do a few test exposures to ascertain what the correct exposure setting should be. This is especially true once one has learned to "read" the histogram rather than trying to appraise exposure based purely on what appears on the LCD screen.
     

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