Macro Help

Discussion in 'Photographic Discussions' started by rjackjames, Feb 15, 2009.

  1. rjackjames

    rjackjames TPF Noob!

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    I ordered a Sigma 150 mm macro lens, the Extension tubes 12, 20, 36 mm and a macro flash but for some reason, it keeps hunting for a focus lock.

    I tried using the extension tubes and the lens and the macro flash outdoors and its still searching for a focus lock?

    Please help or any advice.
     
  2. Battou

    Battou No longer a newbie, moving up!

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    Manual Focus.


    With any real serious Macro work, especially with the use of extention tubes you are considerably reducing the amount of light that reaches the film plain/censor, this is in turn causing the AF issues you are having.

    this high key macro taken with the use of a bellows left my viewfinder so dark to the point my split screen would not work and if a manual focus split screen is having difficulty forget auto focus points.
     
  3. JerryPH

    JerryPH No longer a newbie, moving up!

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    You are not making sense... why extension tubes on a lens that can already do 1:1 macro? Not a good idea, if I understand you in the first place.

    - Is your lens on a camera that is rock solid tripod mounted? (the 105mm is about the biggest you can go hand-held)

    - are you shooting in enough light so that the camera can focus? (Even if you are using flashes, the camera focuses BEFORE the flashes even work)

    - 99% of macro shots should be focused manually anyways, especially with the lens you have.

    I have the Sigma 105mm F/2.8 macro and never had issues with autofocusing, as long as there was adequate light for the camera to be able to focus. If not, I use a little flash-light to assist it's focusing, let it focus, turn off the light and depress the shutter button the rest of the way.
     
  4. Battou

    Battou No longer a newbie, moving up!

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    Using extention tubes on a macro lens that is capable of 1:1 is not an unorthodox practice, merely entering into the range of super macro by exceeding 1:1, I do it with some frequency.
     
  5. rjackjames

    rjackjames TPF Noob!

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    Its a bit cloudy outside and I am shooting like in the f8-16 ranges, I am using the sigma 150mm macro and the MR14EX flash, so i can seem to find the problem hmmmm..........i should have did my homework a little more?
     
  6. Battou

    Battou No longer a newbie, moving up!

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    f8-16 ranges, yup that'll do it.

    Don't feel bad, half of the homework is hands on field work anyway ;)
     
  7. rjackjames

    rjackjames TPF Noob!

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    Yea practice some more when the weather gives me a chance.
     
  8. rjackjames

    rjackjames TPF Noob!

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    I need some Help? My Sigma 150mm lens seems to be autofocusing very slow? is that common with all macro lens? Please advice if i have a defective lens.
     
  9. Overread

    Overread has a hat around here somewhere Staff Member Supporting Member

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    Right first off yes macro lenses are slower then normal lenses for auto focus - even with the HSM motor in the sigma its still a slower lens. Auto focus is just not a prime requirement of macro photography and you will notice that you have to turn the focus wheel a lot to move the focus, because its so precies that means there is even more range for it to move through before it can get to the right focus point.
    Now the lens does have a limiter switch which you can use to limit which region of the lens will use AF for - that can help if you using it for normal work and don't want it to go through all the macro focusing points.

    Do practice to get manucal focusing right- the way I do it is to set the focus wheel all the way over to the closest it can focus (max magnification factor point as well) and then move yourself and the camera close to the subject to aquire focus. If you have AF turned off you can half press the shutter button whilst doing this. That will do two things - firstly it will give you a red af lock on in the viewfinder when you get your foucus right (at the focal points you have active) not essential but can be handy in dimmer light - secondly it means when you hit the shutter you have less distance to press the button and thus make less shake on the camera.

    Also try rocking gently back and forth when you get near the point of focus so that you can get it right where you want it in a shot

    edit - this might also be of interest to you:
    http://www.thephotoforum.com/forum/...rters-extension-tubes-macro-test-results.html
    results with the 150mm macro when combined with teleconverters and extension tubes
     
    Last edited: Feb 18, 2009
  10. rjackjames

    rjackjames TPF Noob!

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    Thanx, I tried it in even bright conditions and I dont even get a lock or a beep. So i am wondering if I have a defective lens. I am on vacation right now, so I have to worry about this lens wen I get back i was hopeing to do some macro work while on vacation, i guess not.
     
  11. Overread

    Overread has a hat around here somewhere Staff Member Supporting Member

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    for macro work you don't need the AF though - turn it into manual mode and then make sure your diopter is set right and then shoot away. If there is an error with the AF it won't impact your shooting that way at all.

    The camera should be able to get a lock onto normal subjects (as I say Af at macro distances is not always going to work - ok on butterflies (there is a lot of target ;)) but smaller things its just not a help to macro work)
     
  12. rjackjames

    rjackjames TPF Noob!

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    I am using it for flowers since there its alot around where I am at.
     

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