Canon Digital 300D and 75x300 F3.3-5.6 III lens with tamron 2x pro

Discussion in 'Digital Photography' started by DEP, Nov 26, 2003.

  1. DEP

    DEP Guest

    Can the 2X damage the zoom lens?

    Would the 1.4 or 1.7 work better?

    What about the non-Pro version?

    Does auto focus work?

    Any comments would be appreciated, as I am new at this and want expand my
    tele capabilities cheaply in order to photo wildlife, etc.

    DEP, Nov 26, 2003
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  2. DEP

    Dave Oddie Guest

    With a 2x converter you lose 2 stops of light so your F3.3 to F5.6 becomes
    something like an F6.6 to F11 optic with dim view through the viewfinder to

    I don't have a clue if that will affect the auto focusing but it can't help
    much and manual focusing will be hard as well.

    I assume you know that with the 1.6 crop factor of the 300D added to the 2x
    teleconverter you end up with a 240-960mm lens which is going to be a bit of a
    handful and require a very sturdy tripod at the tele end.

    Dave Oddie, Nov 26, 2003
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  3. DEP

    Don Coon Guest

    No way a TC can damage a lens. Damage the image, definitely but not the
    Less image degradation, only
    Most probably more degradation.
    Not as well as without the TC because you've reduced the light getting to
    the focusing sensor.
    At 2X you're losing two stops. Thus at 300mm the best you can get is f11.
    Check this link for compatibily of Canon TCs:
    You're definitely going to degrade image quality with any TC on any lens.
    If you start with a very sharp lens, like a Canon "L" series or Sigma "EX"
    series, you'll get a respectable image. You cannot get a very good image
    using a TC on the 75x300; a 2X will be worse than a 1.4X. The better the
    TC (ie. more expensive), the better the results.
    Don Coon, Nov 26, 2003
  4. DEP

    Mark Hanson Guest

    Auto focus will not work AT ALL. Your 75-300/3.5-5.6 lens will become a
    240-960/6.7-11 lens, with crappy optics, uncontrollable shake without a VERY
    sturdy tripod, and no autofocus capability. You'll need a lot of light and a
    steady hand with the manual focus to take good pictures. Not impossible;
    just difficult.

    Mark Hanson, Nov 26, 2003
  5. DEP

    Don Coon Guest

    I agree with everything except the claim that AF will not work at all.
    Maybe not with a Canon TC but maybe with a Tamron 2X or other brand. I KNOW
    AF works with the Tamron 1.4X on a 75-300.

    I was told over and over that AF wouldn't work with my 1.4X. It does quite
    well. If I set it at f/8 (at 300mm), the exposure is right on also. Of
    course the optical quality suffers but I wouldn't say it's "crappy".
    Having said that, I can't predict how the 2X Tamron would work at f/11 but
    I'd wouldn't take as gospel the word of someone who has only used a Canon TC
    or no TC at all (not saying that's your experience, Mark.)

    Also, I assume anyone shooting 960mm should know enough to use a good
    tripod, mirror lockup and the self timer or, in my case, the remote shutter
    release. But I guess that's why people post these questions so they can
    Don Coon, Nov 26, 2003
  6. DEP

    Tom J. Guest

    I have used this combination on a 75-300 IS. It will not harm the camera.
    The AF works but only in bright daylight. At these focal lengths, manual
    focusing is better anyway. The viefinder is more than bright enough to
    manually focus. The results are OK but not great. You can see some curvature
    along the edges and the image is a little soft. If you only occasionally
    want this focal length, it's fine for non-critical use. If this is something
    you want to use on a more regular basis, or you want big enlargements, save
    up the pennies for a long lens.
    Tom J., Nov 26, 2003
  7. DEP

    Sean Nel Guest

    Generally your autofocus is going to start suffering when it goes past 5.6!

    Sean Nel, Nov 26, 2003
  8. DEP

    Sean Nel Guest

    The autofocus will work but when the minimum lens opening is past 5.6 you
    are going to get a lot of hunting. Not really a problem in bright conditions
    but backlight and lowlight will make it short of unbearable.

    Sean Nel, Nov 26, 2003
  9. DEP

    Mark Hanson Guest

    True. Better to say that AF past f/5.6 is somewhat hit-or-miss. Outside in
    bright light you'll probably do well. Inside or in low light...not so much.

    Mark Hanson, Nov 26, 2003
  10. DEP

    Don Coon Guest

    Yup. Bright sunlight it's OK; forget low light.
    Don Coon, Nov 26, 2003
  11. DEP

    Tony Spadaro Guest

    Auto focus quits at f5.6 so you would still have some AF at the short end of
    the range with the 1.4x and a very short part of the range with a 2x. If you
    have teh IS version of the lens it will still IS.
    I would recommend the Kenko Pro 300 as better then the Tamron SP. Near as
    I can tell the Tamron SP is the same as my Kenko MC7 and the Pro 300 is
    better (I own both).
    Neither the 1.4 nor the 2x will damage the lens. You only have to worry
    about certain L lenses and some wide angles, but there is no reason on earth
    to use a TC on a wide angle lens anyway (Although I've done it - and if the
    elements don't hit, it works -- just not very well)

    home of The Camera-ist's Manifesto
    The Improved Links Pages are at
    A sample chapter from my novel "Haight-Ashbury" is at
    Tony Spadaro, Nov 27, 2003
  12. DEP

    DEP Guest

    Looks like the Kenko Pro 300 2x is my choice, I rechecked the reviews and it
    looks better than my Tamron SP about same price.

    Thanks for al the input, I will let you know how it goes.

    PS: Got a good place to buy the Kenko Pro 300?

    DEP, Nov 27, 2003
  13. DEP

    Tony Spadaro Guest

    Tony Spadaro, Nov 27, 2003
  14. DEP

    JPS Guest

    In message <tbdxb.1917$>,
    I've heard that they are exactly the same lens with different paint on
    JPS, Nov 27, 2003
  15. DEP

    Don Coon Guest

    I've read that re the Kenko 200 and Tamron SPAF. The article did seem to
    assume everone knew that all Tamron and Kenko TCs were identical except for
    the name. Also I seem to remember Kenko saying the glass in their's was
    from Hoya. FWIW : )
    Don Coon, Nov 27, 2003
  16. DEP

    Tony Spadaro Guest

    Tony Spadaro, Nov 27, 2003
  17. DEP

    Tony Spadaro Guest

    Tony Spadaro, Nov 27, 2003
  18. DEP

    Tony Spadaro Guest

    Tony Spadaro, Nov 27, 2003
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