§2. System Overview

The Light Counter LC2 from Ian Leake Studio is a specialist light integrator designed for photographers and printers who use ultraviolet-based processes such as platinum/palladium, cyanotype and gum.

The system consists of:

  • The light integrator – the master computer that controls the system 
  • Three different sensors – two for light (UV and visible) and one for temperature
  • An optional power controller – to switch the light source on and off when needed
  • An optional data logger – to record measured data onto an SD card for further analysis
  • A sensor hub – to extend cables and add additional sensors

Light Integrator Module

The light integrator is the heart of the system. It contains a microcontroller which continuously measures light detected by an attached sensor, and it uses these measurements to determine the correct exposure time.

The light integrator samples light about twice per second. This means that it is very accurate over long exposures (10 seconds or more), but less accurate over very short exposures (less than 3-5 seconds). For most historical printing processes this is not a problem because exposure times are typically at least several minutes. However, some silver gelatin processes with very short exposure times may not work well with this system.

LC2 Light Integrator

The Sensors and Sensor Hub

The Light Counter LC2system has three sensors:

  • UV light
  • Visible light
  • Temperature

In its basic configuration, the light integrator is connected to just a UV sensor. This allows the system to measure UV intensity during exposure and adjust the exposure time accordingly. The UV light passes through a 365nm filter which ensures that the sensor only measures the light used for printing, rather than all the other light that is generated by the light source.

Caution: do not touch the UV filter because it is fragile. If you need to clean it then only use a soft brush or hand air-blower (not canned or compressed air which may damage the sensor or filter).

LC2 Ultraviolet Light Sensor

Alternatively, a visible light sensor can be attached to the light integrator. This is intended for use with silver gelatin processes. The light passes through a white acrylic filter, to ensure that non-visible wavelengths do not disturb the sensor.

Caution: do not touch the acrylic filter because it is fragile. If you need to clean it then only use a soft brush or air-blower (not canned or compressed air which may damage the sensor or filter).

LC2 Visible Light Sensor

The temperature sensor allows the photographer to monitor the temperature inside their light box during exposure. This helps to identify potential printing issues due to overheating or other temperature fluctuations.

LC2 Temperature Sensor

In certain configurations it may be necessary to add a sensor hub to allow two sensors to be attached to the same cable (see Section ‎3: Connecting the System).

LC2 Sensor Hub

Power Controller Module

The light integrator works well if the light source is manually switched on/off at the start and end of the exposure. However, it is much more convenient (and slightly more accurate) if the system does this via the optional power controller.

LC2 Power Controller

Data Logger Module

The data logger records exposure and calibration data onto a standard SD card. It can also be used to configure certain light integrator settings.

LC2 Data Logger

Got a question? If so then just send me an email using the address at the bottom of this page, or leave a comment. I will reply as quickly as I am able.

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