Using i3 MK3 as stepper for macro photography
I have modified the firmware of my i3 MK3 so it can be used as a stepper for close-up photography.
When making photo's of small objects, like insects, with large magnifications, like 1x-10x, the depth of field is extremely shallow.
This is overcome by taking a stack of pictures with a small distance difference and sticking these together with the appropriate software, like ZerenStacker, or Helicon Focus.
It typically requires dozend or even hundreds of pictures to be composed. See my website for examples.
I am using my printer for this purpose. I place the camera on the printer bed and let it make steps of 10 micrometers (or a multiple thereof) in the Y direction, which is AFAIK the smallest step size of my printer.
To this end, I have added an extra menu item, where the user can specify step size, travel distance, delay (to await shaking after the bed motion) and an entry to fine tune the Y position in multiples of the step size.
I am using the (free) X_MIN_PIN to control the camera shutter, so the process is totally automatic.
For this, I had to acquire some understanding of the firmware code, which was well doable, fortunately. I would appreciate an overview of the multitasking architecture though, since that is of importance for both the motorcontrol as well as the menu handling. By lack of that, I did a best effort and it seems to be working.
I do understand that this is totally out of scope for the printer itself and therefore I do not expect the patch to be of any value to the mainline.
The patch is currently on top of 3.13.0-RC1.
If anyone is interested, I can make the patch available.
Some more background can be found here