Split grade LEDs enlarger head

· juhe's blog


Disclaimer #

For this project, I used a lot of AI for getting some starting point, doing research about domains I know close to nothing (optic, electronic...) and debbugging microcontroller software (I'm too lazy to read a datasheet in detail).

Goal #

Refurbish an old Omega D2 (maybe ?) enlarger. Build a light box with repeatable exposure.

Non-goals #

Build a perfectly calibrated-according-to-industry-standards light box. I'm working in closed loop and care only about comfort of use, repeatability and the final results I can get. Some calibration procedures and automation are foreseen though (because it's fun to work on that too).

Steps #

  1. Make a diffusion light box to replace the current light bulb + condenser
  2. Make a controller for exposure
  3. Replace worn out / missing focusing mechanism

Light box #

The light box must provide a light with even intensity and even wavelength that will flow through the negative and the lens and hit the photographic paper. Format I use are 24x36, 6x7 and 4x5.

Light is provided by three sets of LEDs

Exposure controller #

The exposure controller ensures that the photographic paper receives the intended amount of light from each channel.

Exposure controller provides a UI for the enlarger head and drives the ATMega328p sending commands to turn on / off, set the intensity etc... via I2C.

Focusing #

Focusing mechanism is made of 3D printed parts and of the shelve parts. Bellows is hand made with thick paper.

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