131 lines
3.9 KiB
Markdown
131 lines
3.9 KiB
Markdown
# PhotoStepper
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A stepper motor controller for use in photography.
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This is a device that can be used to control a stepper motor and a camera, to
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make a defined number of photos with a defined movement in between. A stepper
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motor can be attached to a rotating platform or to a linear drive, so either
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the object or the camera can be moved between the pictures.
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## Hardware
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The device consists of the following components:
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- Arduino Uno, the brains of the operation
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- LCD & keypad shield, as the user interface
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- an A4988 stepper motor driver
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- a 100uF capacitor
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- two PC817 opto-isolators
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- two 1k resistors
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The circuit is pretty simple:
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Atop of that, I used an M13 connector for the stepper motor and a 2.5mm stereo
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phone connector for the camera. To interface my camera, I had a ready made
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cable from a remot camera controller (Ayex AX-5). The whole thing is powered by
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a 12V power supply, connected directly to the Arduino.
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This is the ideal case for the build:
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https://www.thingiverse.com/thing:142282/files
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## Software
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This project makes heavy use of the following libraries:
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- [ArduinoMenu 4](https://www.arduino.cc/reference/en/libraries/arduinomenu-library/) (v4.21.4) for the menu structure
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- [StepperDriver](https://www.arduino.cc/reference/en/libraries/stepperdriver/) (v1.3.1) for motor control
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- [AnalogKeypad by Makuna](https://www.arduino.cc/reference/en/libraries/analogkeypad/) (v1.1.1) for reading input keys
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## Menu structure
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The main menu offers the following features:
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* Jog
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Up and down buttons move the motor manually, pressing the buttons for more
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than a second doubles the speed.
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* Configuration
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General settings for the device:
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* Settle time (tSettle, default 1000ms)
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Pause between motor movement and camera triggers, to avoid blurred images
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because of a shaking camera setup.
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* Focus time (tFocus, default 1000ms)
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Half-press of the shutter button, time to let the camera focus. Usually you
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want to use manual focus when using this device, so it doesn't hurt to
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lower this time.
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* Shutter time (tShutter, default 1000ms)
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How long to press the trigger. Note that you have to setup the exposure
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time on your camera before shooting, this is really only how long the
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button is pressed.
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* Return (default: On)
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Reverse any movement to starting point after shooting the whole scene. This
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allows to repeat the scene with the same parameters.
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* DarkenLCD (default: Off)
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Turn off LCD backlight while shutter is open, used to avoid scattered light
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when shooting in the dark with long exposure time.
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* Scene
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Settings for a particular scene:
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* Steps (nSteps, default 10)
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Number of steps for this scene. You want to take enough pictures to cover
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the whole subject.
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* Distance per step (distance, default 0.5mm)
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How far to move between the steps. This should be set lower than the
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estimated depth of field for the setup.
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* Run
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Run the whole setup, starting with settle time and ending with returning to
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the starting point.
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## Example results
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This is the first image that was made using this project:
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Depth of field for my setup is a little more than 1mm, so this image is
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composed from 30 different shots, each 1mm apart. Here's an animation of the
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non-fused images:
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The images were taken as JPG. For some reason the align-program did strange
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things with my full size images, so I reduced them in size first -- it's only a
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first test:
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```
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for i in *.JPG; do convert $i -resize 50% $i.tif; done
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```
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Then I was able to align all images:
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```
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align_image_stack -ma aligned_ AJ9E94*.tif
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```
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Once all images had been alignes, I created the final image from my stack of photos:
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```
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enfuse -o result.tif --exposure-weight=0 --saturation-weight=0 --contrast-weight=1 --hard-mask --contrast-edge-scale=0.5 aligned_00*
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```
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