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Help needed to use Sigma 105mm Macro lens

Discussion in 'Lens Matters' started by Darth Vader, Aug 4, 2020.

  1. Darth Vader

    Darth Vader Active Member


    I have just brought a Sigma 105mm F2.8 EX DG OS HSM Macro lens and I have 2 questions as I have never used a macro lens before.

    1. What is the difference between OS 1 and 2?

    2. Can someone explain what these mean…...Full – 0.45m – 0.312/0.45m

    Thank you for your help.
  2. MJB

    MJB Well-Known Member

    1)OS1 corrects for all lens shake, OS2 for vertical movement only.

    2)it's the focussing distance range. Set on 0.312-0.45m means the lens wont hunt for focus outside this distance.
  3. PeteRob

    PeteRob Well-Known Member

    What he said.

    Lens based image stabilised systems have either 1, 2 or 3 modes. Mode 1 stabilises the lens to up/down and left/right movement. Because some people like to follow movement by panning, and panning is usually left/right, mode 2 disables this stabilisation so that the IS isn’t fighting the panning movement. Mode 3 is very recent - it is the same as mode 1 but IS only activates when the shutter is released and not on the half-pressure used for focussing.

    It is common to be able to preset the focussing range for macro and for telephoto lenses. Both type of lenses work with shallow depth of field and the focussing mechanism is low geared to allow very small focus adjustments to be made. If the lens “hunts” for focus it takes an age to wind through the focus range. Therefore a switch on the side of the lens limits the movement. It is important to check the position of the switch before using the lens because there is nothing so frustrating as finding that you cannot focus on what you want to because the switch is in the wrong position.
  4. Stephen Rundle

    Stephen Rundle In the Stop Bath

  5. Darth Vader

    Darth Vader Active Member

    Thank you all for your help.
  6. Fen

    Fen Well-Known Member

    And don't forget to turn OS off when mounted on a tripod, it can burn the motors out!
  7. PeteRob

    PeteRob Well-Known Member

    Depends on the camera/lens combination - these days, with some equipment, stabilisation will not activate if the vibration is below a certain threshold - but certainly turning it off will avoid any problem.
  8. Fen

    Fen Well-Known Member

    It's actually in the manual for that lens :)
    MJB likes this.
  9. PeteRob

    PeteRob Well-Known Member

    Ah - well then - excellent advice though I'd not heard of the motors burning out before. I'll have to look up the manual for my macro lens if ever I get around to buying a geared head and focussing rail for the tripod.
    Fen likes this.

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