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Posts Tagged ‘multi-focus’

Working with very large depth of field situations

July 16th, 2010 No comments

While doing some very late macro flower photography the moon decided it was going to look very interesting. Having had only my Canon EF 100mm Macro lens with me, there wasn’t a lot of “moon shot” that I could take, so I decided to incorporate the moon into the picture.

The equipment I had with me:

Canon 1Ds Mark II, 100mm f/2.8 Macro Lens, 580EX II Flash with extension cable, 12, 20 and 36mm extension tubes, large and small silver and gold reflector, finally my Tripod.

  • Lens extenders although make you be able to get in really close to a subject, like a sleeping bee (okay maybe it’s SLEEPING sleeping) you do lose your infinite focus. Remove all extenders before starting.
  • Setup tripod and compose your shot, focusing back and forth until you have the shot you want.
  • I tried a couple of different techniques to get the shot.
  1. First, a multi-focus shot. This is very similar to doing a HDR or Exposure Bracket, where you take a couple of exposures based on different settings so that you can combine them later for a higher light to dark range.
    1. Focus on the moon, take a shot: 1/250th @ f/6.3, ISO 100 – flash fired away.
    2. Without moving anything — refocus on the flower, take a shot: 1/250th, @f6.3, ISO 100, Flash fired at flower from right.
    3. Combine the two images in Photoshop as two layers, and mask. I’ll redo the steps on how I did this in a post tomorrow.

    2. Moon focus shot

    Final image, combined in PS, finished in LR3

    Flower Focus Shot

  2. Second, a single shot trying to get as much as possible into DoF.
    1. I moved as far as back as I could. Increased distance to subject increases depth of field.
    2. Note that the moon’s focus is infinity.
    3. Focus on the flowers, and note the distance on the lens. Go half way between them, which were just about at the edge of infinity.
    4. Change aperture to f/32, as with the smaller the aperture the larger the depth of field.
    5. Take a single shot with flash pointing at the flowers, as right and higher as I could reach without pulling the camera.

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