Macro DOF issues

Discussion in 'Macro' started by mostirreverent, Jun 5, 2018.

  1. I thought that by being so close to my subject, especially using a 20mm extension tube on my 60mm micro, that by using a smaller opening (f 10 or 32), I would increase just the “local” DOF. Instead, I did, but it also led to the “far” background being more in focus. When I stop down to an f3 I get the desired lose of detail in “far” background, but also the DOF “locally” where I want more in focus.

    What am I doing wrong? I've seen other folks that seem to get so much more in focus while still blurring the far background…

    [​IMG]

    Still too much background in focus
    [​IMG]
     
  2. In macro, step down is just not enough to increase dof due to very close distance from camera to subject.
    Many cases, it is needed to do focus stacking to get thicker dof.
     
  3. There's no independent control over "local" vs. "far" DOF other than by changing vantage point and then changing lens focal length for the coverage you want. Even that might not get you what you want- what did we ever do before focus stacking? I've forgotten the math, but going to a larger format probably helps. I know the opposite is true- with tiny sensors you end up with everything sharp whether you want it or not.
     
    timcox likes this.
  4. I've never done focus stacking…That makes a lot of sense (and work :) )
    As for the larger format conrad, do you mean medium format? I'm shooting with an FX D3s now.

    Would a shift on a bellows help? I miss my old minolta auto bellows III, and have been looking for ways to fit it with adaptors.
     
  5. I suppose a tilt feature would be more desirable since it permitts asorting a narrow focal plane with your subject, but it would bring some part of the background out of blur too. I suppose Conrad refered to anything larger i.e. even LF - Somebody released a 8x10" back recently.
    Let's get practical: Considering how small the flowers you are shooting are, why not bring a portable studio backdrop of your choice, if you want a neutral nothing in your image? - I like your "still too much background in focus" image as is and would call the background "somewhat recognizable OOF".
    I recently bought a pack of plastic mats supposed to lay between dirty workbench and breakfast table as portable macro studio backdrops they are easy to carry and hold. - Making something like a painters easel for them with an ultra shaky bad joke of a tripod or maybe even surplus fiberglass tent poles should be possible.
    I'm not aware of any just optical solution. - At least I haven't tested Sony's recently released speciality lens. I really believe the portable studio approach or postprocessing to be easier solutions and usually I am complaining about no way to get enough DOF on my macro subjects.
     
  6. I do have a bunch of pvc sheets. I sometimes use them for lighting, or to block the wind. I swear, if lighting is in my favor, the wind is not…

    I do like this shot. though upon seeing it again, I did realize that the flower on the right with the droplets would have been a good subject in itself. The trouble was, it was drizzling out, and I was half way into someone's garden as it was, and also trying not to bang the droplets off :) I have to say too, that is is pretty shark for my cheap telephoto, closed down.

    [​IMG]
    Foxglove, f32, 70-300mm G, 20mm extension tube, tripod
     
  7. Shoot with a much longer focal length lens, like 200-300mm, or choose a subject with a much more distant background. And as others have recommended, shoot at f/4 and focus stack.
     
  8. paul ron

    paul ron NYC


    sorry im not savy at digital terms..

    what is focus stacking and how is it done?
     
  9. Wikipedia - "Focus stacking (also known as focal plane merging and z-stacking or focus blending) is a digital image processing technique which combines multiple images taken at different focus distances to give a resulting image with a greater depth of field (DOF) than any of the individual source images."

    You can do it in Photoshop via layers and Smart Objects, but Helicon is probably the most effective way to do it.

    Helicon Focus - Helicon Soft

    The Nikon D850 has a focus shift feature, which allows you to automatically capture the same image at multiple focus points. You can then bring those images into Helicon or PS or some other software to stack them into a single image with greater DOF.
     
  10. paul ron

    paul ron NYC

    Just what I thought.
    Thanks.
     

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