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

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*