Island in the Net

A personal blog by Khürt Williams, full of inchoate writing on photography, coffee, and geekery.

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Using Macro Extension Tubes

I’ve had the Kenko Auto DG 12mm, 20mm, and 36mm macro extensions tubes for over a year but I have not used them much. When I bought them I was very excited but had little experience with macro. I still have little experience wit macro. This summer I experimented with shooting macros of sunflowers and insects but I do not like the results.

The Extension Tubes have no optics but extend the distance between the lens and the camera sensor. The result is that the focusing point on the sensor is moved closer to the front of the lens. This allows a lens to focus closer than the normal focusing distance of that lens. This magnifies the subject making it appear larger. This is useful for doing macro photography without a dedicated macro lens.

Recently I was reading some of the feeds in the WordPress Reader. One of the articles about macro photography inspired me to pull out my Nikon 85mm f/1.8 and my Kenko Auto DG 12mm, 20mm, and 36mm extension tubes. The Kenko DG extensions tube set has three tubes of different length – 12mm, 20mm, and 36mm – which are stacked individually or in combination to increase magnification. I wanted to test which set of tubes would work well with the lenses I have; my AF-S Nikkor 35mm f/1.8 or my AF-S Nikkor 85mm f/1.8.

I wasn’t sure which lens to use with the extension tubes but I shot one image with the Nikon 35 mm f/1.8 and realised that the focusing distance was much too shoot. The front of the lens was mere millimetres from the subject. The point of the extension tube is to be able to shoot close up and magnify the image. Because the 35mm already has a short focus distance, using the Kenko moved the focus distance so close, it was basically inside the lens itself.

Switching to the 85mm provided magnification but enough subject to camera lens distance to allow me to shoot closer. I chose “Mal” as my subject. I received the figurine in one of the Loot Crate I received last year. “Mal” is the name of the main protagonist from the show “Firefly”. It was one of my favourite shows until it was cancelled after just one season. I’m not sure why I enjoyed this show so much but I’ve watched it several times on Netflix. Maybe I liked the characters because they were regular people just trying to survive in a dangerous universe. Maybe I like the show because the characters are very human, flawed. Mal means “bad” in French. The Firefly characters became like family to each other. And to me.

The feature image for this post is the subject shot with my AF-S Nikkor 85mm f/1.8 without extension tubes. I then attached the 12mm and took another photograph. With this extension, I was able to get in much closer to “Mal”. The magnification ratio with the 12mm is approximately 1.25. The image should appear 1.25 larger in my viewfinder.

Because the extension tubes also impact the depth of field, for each tube I adjusted the aperture to increase the depth of field. This of course, also increased the exposure times. To keep things in focus, I shot these images with the camera mounted on a tripod.

Using Macro Extension Tubes, KENKO DG 12mm NIKON D5100 20160922 4198

AF-S Nikkor 85mm f/1.8 with Kenko DG 12mm extension tube

  • Aperture—ƒ/8
  • Camera—NIKON D5100
  • Taken—22 September, 2016
  • Copyright—© Khürt L. Williams
  • Focal length—85mm
  • ISO—100
  • Shutter speed—1s

The next image below was taken with the 20mm extension attached. The magnification ratio of the 20mm tube is approximately 1.36. I was able to move in closer to Mal and fill my viewfinder.

Using Macro Extension Tubes, KENK DG 20mm NIKON D5100 20160922 4200

AF-S Nikkor 85mm f/1.8 with Kenko DG 20mm extension tube

  • Aperture—ƒ/11
  • Camera—NIKON D5100
  • Taken—22 September, 2016
  • Copyright—© Khürt L. Williams
  • Focal length—85mm
  • ISO—100
  • Shutter speed—3s

I swapped out the 20mm and attached the 36mm. I didn’t test with the 20mm and 12mm together. The combined magnification is too close to what can be obtained with the 36mm alone. The magnification ratio of the 36mm tube is approximately 1.59. The differene in magnification is tiny.

Using Macro Extension Tubes, KENKO DG 36 NIKON D5100 20160922 4201

AF-S Nikkor 85mm f/1.8 with Kenko DG 36mm extension tube

  • Aperture—ƒ/11
  • Camera—NIKON D5100
  • Taken—22 September, 2016
  • Copyright—© Khürt L. Williams
  • Focal length—85mm
  • ISO—100
  • Shutter speed—2.5s

Lastly, I stacked all the tubes together and took my last shot. It’s like Mal’s is life size and staring at me from right in front of the lens. The combined magnification ratio is approximately 2.79. Not at all 1:1.

Using Macro Extension Tubes, KENKO DG 12 24 36 NIKON D5100 20160922 4206

AF-S Nikkor 85mm f/1.8 with Kenko DG 12mm+20mm+36mm extension tube

  • Aperture—ƒ/16
  • Camera—NIKON D5100
  • Taken—22 September, 2016
  • Copyright—© Khürt L. Williams
  • Flash fired—yes
  • Focal length—85mm
  • ISO—100
  • Shutter speed—1/60s