A&P So I rented a 500mm f4 for the week but it's back focusing.

Discussion in 'Lifestyle' started by CornUponCob, Mar 23, 2008.

  1. CornUponCob

    CornUponCob New Member

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    I shot 1161 images today testing the 500mm f4. I shot Rugby, Baseball and some Tennis (a bit long for tennis, but whatever).

    The IQ of the lens is great, everything I've read about it seems to be true, but unfortunately, on BOTH of my 40Ds it's back focusing by what seems to be a fixed %. I have a 10-22, 135L and 85L II that all focus perfectly on my 40Ds. I know it's not my cameras' fault. The back focus is noticable and consistant throughout 95% of the 1161 images.

    If the object is close, the BF is only by a few inches. If the object is far, it's by up to 1.5 feet or so.

    The store I rented it from is closed on Sunday. Monday, Tuesday, and Wednesday I'll be gone all day long covering a golf tournament. That means no time to take it back for a replacement. I called them today and left a message about the performance of the lens, we'll see what happens. I'm a regular at the store.

    I'm including a few sample images, ONE that shows the back focus. The rest just for the hell of it.


    OOF rugby shot
    [​IMG]



    OOF baseball shot
    [​IMG]




    Slightly OOF tennis shot
    [​IMG]




    100% crop of a nearly stationary ball that clearly illistruates the back focusing
    [​IMG]




    This shot actually IS in focus. It was one of a series of 4, the other 3 are back focued. This one somehow came out OK and illistrates what the lens is capable of. This is the origional image, sharpening set to 7 in DPP
    [​IMG]
     
  2. Blair

    Blair New Member

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    fucking impressive squirrel shot. shame about the BF.
     
  3. mojito

    mojito New Member

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    if you had a mk3 you could correct it :hs:
     
  4. CornUponCob

    CornUponCob New Member

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    One of the first things I thought about when I got home.

    I'm mostly just surprised that a canon lens is mis-focusing on my bodies... especially an ultra-telephoto. Of all the reviews I've read about these lenses, I've only come across a handful of people talking about focusing issues (and those are usually in regards to the 300 f4, or 400 5.6)
     
  5. PEnGUiN188

    PEnGUiN188 New Member

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    I wanna see a pic of this lens on the 40d.
     
  6. skolen

    skolen Guest

    Good lord, look how far you are in the squirrels eye. So sharp.
     
  7. isaac86hatch

    isaac86hatch This thread sucks

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    What mode were you shooting AI Servo/AI Focus/One Shot? I once heard that the AI's mixed with IS could cause back focusing. Could be wrong though. :dunno:
     
  8. dew

    dew Banned

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    i want a working version of this lense
     
  9. xenon supra

    xenon supra OT Supporter

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    nice shots.

    whoop whoop gt :h5:
     
  10. mojito

    mojito New Member

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    with a rental its not surprising. I doubt is was bad off the factory line.
     
  11. CornUponCob

    CornUponCob New Member

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    AI servo the whole time. Usually center focus point, but all focus points for tennis.

    I shot a mixture of IS on and IS off, as well as on a monopod and handheld.

    It actually reminded me how much I hate shooting with a monopod. About 60% of the shots were shot handheld. It's heavy, but as long as you put it down (let it hang on my belt) between action, it's completely manageable hand-holding.

    I'm going to go shoot a practice round of golf today. I'm going to try stopping it down to see if I can get the players in the DoF. That's not really ideal because what's the point of a 500 f4 if you're only going to shoot it at 5.6?

    I always have the sigma 100-300 f4 to fall back on which I've shot golf with before.
     

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