Macro Photography of Beetles - Part 3

Part 1 of this project talks about the initial project concept and testing.  Part 2 goes into building the Macro Prototype Rig.  This blog post describes some of the electronics that operate the rig.

Having worked with PICAXE chips before and having a few left over from other projects, I new from the beginning that I would use one to control the prototype rig.  Initially I played around trialling different methods of user input and output.  This is a close up of the board mid way through the development and testing:

The prototype is designed to be mobile, so it operates from a 7AH 12V sealed lead acid battery. The unit draws around 300mA with the LED array lit up and 50mA with the LED array off.  The servos only operate very briefly.  On a fully charged battery, I can operate the rig for over 12 hours continuously.  A busy electronics desk:

At this stage I had an operational but very manual prototype rig, so I undertook a number of trials, and processed a chrysalis that I found in my back yard and a couple of vials containing 14 beetles.  This is an info sheet I compiled to show the photographs that went into CombineZP software and what it generated:

Viewing a beetle photograph on my monitor, I noticed that the beetles shell seemed to fluoresce under the white LED light.  It was something that I hadn't noticed looking at it directly.  I went back to the electronics desk to have a closer look, but couldn't really see anything special.  It was a bit later, when I realised that the LED Array lights where reflecting off the shiny surfaces:

Hmm, time to trial a light diffuser.  This ended up being made out of a cylinder of standard printer paper:

Here are a few focus stacked photographs of beetles I processed during the trial:

  Note the haloing effect from movement in one or more of the beetle photographs.

  Some sections are still out of focus.  I could have used more photographs, with finer intervals.

And a nice spider my wife asked me to remove from the kitchen.  That is one hairy spider.  The resultant photograph is over 500mm wide on my monitor:

I mounted the beetles, and stored the days work in my home made prototype display box.  This was made of Jarrah floor boards.  Once I have identified the beetles and labelled them, I will mount them on a proper foam board inside the box and seal it up:

Since this is just a prototype macro photography rig, the functionality has been designed to be very flexible.  I started with a few user input buttons, and ended up with 6 buttons, each having a feedback LED.  Here is the front and back of the user interface board:

The above six button (Left to Right), current functions are:

1. Move the stage up an increment 
2. Set the stage floor level.  This is set by the blue pot. on the side.
3. Set stage increment.  This just toggles either a small, medium or large increment.  The LED flashes once, twice or three times correspondingly.
4. Set camera into focus mode (move camera button to first level)
5. Take a single photo (depress camera button all the way down, and brings it back to first level - focus)
6. Take a sequence of photos (move stage, take photo, move stage etc), until the stage servo reaches the end of the limits.  Increments are set by the third button.

With the above board built, I moved onto the controller board.  Since this is just a prototype, I just hand soldered the components together on vero board.  Red/Blue = power, white=data in (mainly switches), yellow is data out, (mainly LEDs):

You can find my Eagle schematics (Ver: 6.1), for both of the boards attached below and low-resolution screenshots here:

  User interface board

  Controller board

Here is the completed rig outside nearly in the wild.  Yes, with the electronics mounted on top, this is not to be used outside in the wet weather:

The current PICAXE source code as of: 2012-04-21 - is listed below.

So, to review this prototype project,  what would I do differently the next time around:

• Build a much larger light box, so that I can photograph larger items.  Make sure there is still a lot of light reaching the object when the stage is at it's highest.
• Build a holder for the internal light defuser, so that it won't move around or fall out when the rig is being moved around or upside down.
• Figure out a way to photograph objects coming in from a side window, as opposed one through the floor.  This will help with photographing flowers etc.
• Build a larger, lighter and neater platform, so it's easier to mount electronics underneath the stage.
• Integrate the stage servo onto the photo rig, so there is only one less device to carry around.