Extender Question

Discussion in 'Photography Beginners' Forum' started by sweigner, Apr 10, 2008.

  1. sweigner

    sweigner TPF Noob!

    Joined:
    Apr 10, 2008
    Messages:
    2
    Likes Received:
    0
    I currently have a EF 75-300mm f/4-5.6 III Lens on my Digital Rebel. I was looking at the Canon EF 2x II Telephoto Lens Extender. Can I use this with the 75-300mm?
     
  2. JimmyO

    JimmyO TPF Noob!

    Joined:
    Feb 3, 2008
    Messages:
    2,132
    Likes Received:
    0
    Location:
    NJ
    Can others edit my Photos:
    Photos NOT OK to edit
    I think it only works with L glass, sorry. But i might be wrong.
     
  3. 250Gimp

    250Gimp TPF Noob!

    Joined:
    Oct 3, 2006
    Messages:
    1,031
    Likes Received:
    0
    Location:
    Chelsea, Quebec
    Can others edit my Photos:
    Photos OK to edit
    I think JimmyO is correct. There may be a work around by taping pins, but I'm not sure.

    Kenko makes extenders, and I believe that they will work with your lense, but I would confirm on their website. You will loose a couple stops on your aperature when using extenders, and it may affect auto focus on your camera, unless it is really bright out.

    CHeers
     
  4. JimmyO

    JimmyO TPF Noob!

    Joined:
    Feb 3, 2008
    Messages:
    2,132
    Likes Received:
    0
    Location:
    NJ
    Can others edit my Photos:
    Photos NOT OK to edit
    Also keep in mind that the lower the less the multiplaction the better the image quality. If you can you should consider the 1.4x or 1.6x before the 2.0x. And like gimp said you will lose 2 stops of light with the 2x, which is alot. This is why there mainly used on f/2.8 lenses.
     
  5. sweigner

    sweigner TPF Noob!

    Joined:
    Apr 10, 2008
    Messages:
    2
    Likes Received:
    0
    Thanks Guys!!
     
  6. Mystwalker

    Mystwalker TPF Noob!

    Joined:
    Jan 25, 2008
    Messages:
    544
    Likes Received:
    0
    Can others edit my Photos:
    Photos NOT OK to edit
    My understanding ...

    x1.4 - you will lose 1 stop so you are basically @ 300x1.4 f/8 ... unless you have a 1D series, you lose autofocus after f/5.6 - 1D series, after f/8

    x2.0 - you lose 2 stops so you are @ 300x2 f/whatever it is after 8 (11?) :) ... you lose autofocus period.

    I think recommendation to use on f/2.8 Lens is that losing two stops will still allow you to autofocus. Do not know about that pin stuff ... but something expected of Canon. I have the Kenko x1.4 Pro - not as metallic as Canon, but works well. It is not weathersealed either.
     
  7. gryphonslair99

    gryphonslair99 Been spending a lot of time on here!

    Joined:
    Sep 9, 2006
    Messages:
    11,437
    Likes Received:
    2,095
    Location:
    Wichita, Kansas, USA
    Can others edit my Photos:
    Photos OK to edit
  8. christopher walrath

    christopher walrath No longer a newbie, moving up!

    Joined:
    Mar 19, 2008
    Messages:
    1,265
    Likes Received:
    23
    Location:
    In a darkroom far, far away...
    Can others edit my Photos:
    Photos NOT OK to edit
    Say you have a 50mm f/2 lens. If you use a 1.4 teleconverter your maximum aperture becomes f/2.8 because you extend your focal length to 70mm and your maximum aperture diameter is still 25mm. If you use a 2x teleconverter you reduce your maximum aperture to f/4 because you have extended your focal length to 100mm while keeping that 25mm aperture diameter. With a zoom you only lose about 1-1.5 stops of light (70-210 or so). With a teleconveter I tested with my MD lenses I had an additional light fall off when compared to similar FL zooms, about an addition half stop. And the image quality goes down. And on long telephotos I found a slight focus shift mear infinity.

    This said, if you have four or five prime lenses, a teleconverter could be an economic means to get even more focal length options. But a couple of zooms would honestly be the highest quality way to go.
     
  9. soylentgreen

    soylentgreen TPF Noob!

    Joined:
    Feb 27, 2007
    Messages:
    735
    Likes Received:
    2
    Location:
    Miami, FL
    Can others edit my Photos:
    Photos NOT OK to edit
    The Canon teleconverters ONLY work on the L series telephoto and super-telephoto lenses minus the 100mm soft-focus.
     
  10. davebmck

    davebmck TPF Noob!

    Joined:
    Mar 10, 2008
    Messages:
    678
    Likes Received:
    0
    Location:
    Waxhaw, NC
    Can others edit my Photos:
    Photos NOT OK to edit
    You don't lose auto focus after 5.6 on the Rebel. I have a zoom that is 6.3 fully zoomed and it works fine. It can hunt in low light, but I have no problems in good light.
     
  11. davebmck

    davebmck TPF Noob!

    Joined:
    Mar 10, 2008
    Messages:
    678
    Likes Received:
    0
    Location:
    Waxhaw, NC
    Can others edit my Photos:
    Photos NOT OK to edit
    Opps. Double post.
     

Share This Page