PhotoStepper

A stepper motor controller for use in photography.

This is a device that can be used to control a stepper motor and a camera, to make a defined number of photos with a defined movement in between. A stepper motor can be attached to a rotating platform or to a linear drive, so either the object or the camera can be moved between the pictures.

Hardware

The device consists of the following components:

• Arduino Uno, the brains of the operation
• LCD & keypad shield, as the user interface
• an A4988 stepper motor driver
• a 100uF capacitor
• two PC817 opto-isolators
• two 1k resistors

The circuit is pretty simple:

Atop of that, I used an M13 connector for the stepper motor and a 2.5mm stereo phone connector for the camera. To interface my camera, I had a ready made cable from a remot camera controller (Ayex AX-5). The whole thing is powered by a 12V power supply, connected directly to the Arduino.

This is the ideal case for the build: https://www.thingiverse.com/thing:142282/files

Software

This project makes heavy use of the following libraries:

• ArduinoMenu 4 (v4.21.4) for the menu structure
• StepperDriver (v1.3.1) for motor control
• AnalogKeypad by Makuna (v1.1.1) for reading input keys

Menu structure

The main menu offers the following features:

• Jog

  Up and down buttons move the motor manually, pressing the buttons for more than a second doubles the speed.

• Configuration

  General settings for the device:

  • Settle time (tSettle, default 1000ms)

    Pause between motor movement and camera triggers, to avoid shaking.

  • Focus time (tFocus, default 1000ms)

    Half-press of the shutter button, time to let the camera focus.

  • Shutter time (tShutter, default 1000ms)

    How long to press the trigger.

  • Return (default: On)

    Reverse any movement to starting point after shooting the whole scene.

  • DarkenLCD (default: Off)

    Turn off LCD backlight while shutter is open.

• Scene

  Settings for a particular scene:

  • Steps (nSteps, default 10)

    Number of steps for this scene.

  • Distance per step (distance, default 0.5mm)

    How far to move between the steps.

• Run

Run the whole setup.

Example results

This is the first image that was made using this project:

Depth of field for my setup is a little more than 1mm, so this image is composed from 30 different shots, each 1mm apart. Here's an animation of the non-fused images:

The images were taken as JPG. For some reason the align-program did strange things with my full size images, so I reduced them in size first -- it's only a first test:

for i in *.JPG; do convert $i -resize 50% $i.tif; done

Then I was able to align all images:

align_image_stack -ma aligned_ AJ9E94*.tif

Once all images had been alignes, I created the final image from my stack of photos:

enfuse -o result.tif --exposure-weight=0 --saturation-weight=0 --contrast-weight=1 --hard-mask --contrast-edge-scale=0.5 aligned_00*