Sunday, October 6, 2013

Microphotography using a home-built focusing and lighting rig

Super Macro: Crane fly wing - 16 image stack shot using a Reichert Plan 10/0.25 160/- microscope objective mounted on a 50mm extension tube on the rig shown below
In recent times, I have been fascinated and inspired by the amazing images produced by photographers such as John Hallman, Brian Valentine (Lord V) and Charles Krebs.

A couple of weeks ago I decided to try my hand using microscope objectives on my DSLR. The first objective that I tried was a Reichert Plan 10/0.25 160/-, having heard good reports of the Austrian made Metallurgical objectives.

The only problems with using this setup is that the working distance can be as small as a few millimeters, with a depth of field of 1/10th of a millimeter or smaller. As a result focusing needs to be very precise and it is necessary to perform minute incremental adjustments in focus by moving the whole camera and lens. Additionally, the whole setup needs to also be sturdy and free of vibrations.

With these requirement in mind, I decided to build a dedicated microphotography rig which I could use longterm. Being a bit of a hoarder and tinkerer, I decided to try and keep the construction to using materials and parts that I had lying around the house as far as possible.

In the end, the parts list consisted of the following:

Purchased Parts:
  • 12V gear head DC motor 
  • Arduino Micro controller Board
  • H-Bridge motor control shield for the Arduino board.

Parts Scavenged from Around the House:
  • Timber base board
  • Timber block to mount track column onto.
  • Rubber bath plug (base for stage lighting module)
  • 2x $3 9-LED mini flashlight/torches (to make mini ring light and stage backlighting)
  • 1x unloved Glass screw in UV filter for a camera lens (specimen stage). 
  • PVC pipe (for mini-ring light ring)
  • Electricians's tape
  • Several bolts and screws
  • No-name brand 4-way Macro Rail Slider
  • Disused mounting plate from assembly from tripod head.
  • Plastic cogs salvages from a broken tape-deck
  • Button panel salvaged from a broken sound-system
  • Various electronic components salvaged from broken sound-system
  • Partial modified lens assembly from disused 2x teleconverter (used to concentrate light for specimen stage).

Images of the Rig are shown below:

Full Rig Showing Focusing Mechanism and Specimen Stage

Ready to Shoot
Focusing and Lighting Electronics
Stage Backlight Showing Magnifying lens made from the modified lens assembly of a 2x teleconverter
Mini LED Ring Light
Stage Backlight With Lens Removed

Stage Backlight With Specimen Surface (Glass UV filter)
Stage Backlight With Specimen Surface (Glass UV filter) and Mini Ring Light