Lens Diffraction and macro Lenses

Discussion in 'Native Lenses' started by Paul80, Mar 23, 2015.

  1. Paul80

    Paul80 Mu-43 Veteran

    254
    Jul 6, 2014
    Hi all

    We obviously all know that lens diffraction means that most lenses give their best sharpness results no more than about 2 stops down from wide open with the image getting softer the more the lens is stopped down.

    but what about macro lenses is it the same with them or are they corrected to give better results at the smaller apertures they are more likely to be used at.

    Just wondering as I have been playing with my new Olympus 60mm Macro and not getting the sharpness I would have expected at around f11 & f16 even though I am using flash so camera and subject movement should not be an issue.

    Am I fighting diffraction at those apertures.

    Thanks

    Paul
     
  2. PacNWMike

    PacNWMike Mu-43 Hall of Famer

    Dec 5, 2014
    Salish Sea
    guess?
    Yep, physics rules. You have to sacrifice sharpness to get DOF. A conundrum.
     
  3. Paul80

    Paul80 Mu-43 Veteran

    254
    Jul 6, 2014
    thanks

    I will have to do some more experiments with this lens to see how far it can be pushed before softness takes over.

    Paul
     
  4. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    AFAIK diffraction is in no way related to the rule of thumb of two stops from the maximum aperture. They are different things and usually do not overlap.

    On a m43 sensor with 16MP you should start to see some diffraction, as you found out, from f/11 (or even f/8). A tripod with self-timer is the best way to test this things.

    There is no "fix" for diffraction, there are a few software that can do some "diffraction correction", like CA and distortion, but are not (yet) common.

    For macro the common solution is focus stacking, using a wider aperture.

    If you were using a very fast shutter speed and you were very close the problem could be just focus: the DoF is so small, a few millimeters, that the subject easily goes out of focus with a little camera movement.
     
  5. tkbslc

    tkbslc Mu-43 Hall of Famer

    Yes and no. Out of focus is always softer than diffraction blur.
     
    • Agree Agree x 1
  6. ManofKent

    ManofKent Hopefully still learning

    789
    Dec 26, 2014
    Faversham, Kent, UK
    Richard
    I find the diffraction impact at f8 is pretty negligible to the point I don't worry about it. f11 does tend to be noticeable, but sometimes usable. It's a rule of thumb and sometimes additional dof is worth the cost.