Light Counter LC6 Beta Test Support

Thank you for your support beta testing the new Light Counter LC6 from Ian Leake Studio. These notes are intended to help you to successfully test the LC6 and its system peripherals.

The LC6 is the most powerful, accurate and easy to use light integrator and darkroom timer available today. It is the latest (and best) device in the Light Counter system that has helped hundreds of photographers worldwide to gain maximum control over their printing process.

The LC6 has a large, high resolution, touch-sensitive display. There are no fiddly knobs and buttons, no cryptic displays, and no strange control codes to memorise. In the words of the late, great Steve Jobs: it just works.

New in the LC6: The LC6 has a state-of-the-art dual-core microcontroller. This chip is blistering fast, allowing much more complicated and precise real-time calculations than previous the generations.

One core is dedicated to the sensors and other peripherals. Depending on the sensors you use, it will make measurements as often as every 20 milliseconds to ensure ultra-precision. The new universal sensor automatically adjusts its sensitivity depending on the brightness of the light – so it is less likely to get overwhelmed by very bright lights, but also won't lose very low light levels either.

The other core manages the exposure process, and the glorious 5" 800x480 display. It is controlled by touches and swipes, just like your phone. And, because you're in a darkroom, you can completely switch off the display and still operate the LC6.

Happy printing!

Getting Started

Major functions are controlled by the command buttons at the bottom of the touch-screen display.

You can navigate between screens by touch-sliding left and right across the display. You can switch the display off from any screen by sliding down from the top of the display. Sliding up from the bottom will re-awaken the display.

In the top right corner of the display are small icons that show which peripherals you have connected. The LC6 is backwards compatible with most older sensors and peripherals, except data loggers which are no longer supported.

Connecting Power and Peripherals

The LC6 rear panel has 6 x USB-A connectors. These are for sensors, power controllers and other peripherals. These must never be connected to a computer or other USB device because this may damage the LC6.

Also on the rear panel is a single USB-C connector. This has two functions:

  1. In normal use the power cable is connected here. The power can be taken from a standard USB power block, battery or computer. It can also be taken from the dedicated LC6 power supply designed for mounting inside a light unit.
  2. The USB-C connector can also be used for firmware updates from your computer. Instructions for these are given below.

The final item on the rear panel is the power switch. If the LC6 is stuck 'on' and the power switch is unable to switch off the device, then please check that you haven't got power connected to the USB-A sensor connectors.

Exposures and Exposure Plans

As with previous Light Counter devices, exposures can be based on either elapsed time or measured 'units' of light. If a suitable light sensor is not attached, then the LC6 will only allow timed exposures.

You can start an exposure or exposure plan by touching the command button on the right (the button with the light bulb icon).

You can edit the current exposure from the main screen by touching the edit command button (pencil icon). You can select, set and delete exposure presets by touching the presets command button (star icon). You can define exposure plans of multiple exposures by touching the exposure plan command button (star with plusses icon).

Up to 12 presets can be defined. Timed exposures can range from 0.1 second to 9 hours, 59 minutes and 59.9 seconds. Unit exposures can range from 0.1 unit to 9,999.9 units. The LC6 is accurate to 0.1 second and 0.1 units.

New with the LC6: As of firmware version 0.3.4 the exposure presets can be given names containing up to 12 letters, digits or spaces.

Up to 4 exposure plans can be defined. There are three types of exposure plan: test strips, series and f-stops.

Test Strips: These are automatically generated test strips exposures. They have a four attributes:

  • Base Exposure – which is either the lowest exposure, highest exposure or the middle exposure depending on whether you select 'from base', 'to base' or 'bracket base'.
  • Step Size – either full, 1/2, 1/3, 1/4, 1/6 or 1/12 stops
  • Number of Steps – 3, 5, 7, 9, 11 or 13 steps
  • Incremental or Full

Incremental exposures build on previous exposures by adding additional exposure to make up the step size. For example, 3 incremental 1/2 steps from 10 seconds would give 10s, 4.1s (total 14.1s) and 5.9s (total 20s). Incremental exposures are best suited to using a card to progressively cover your exposure area with each step.

Full exposures generate the full exposure for each step. For example, 3 full 1/2 steps from 10 seconds would give 10s, 14.1s and 20s.

Series Exposure Plans: These support up to 16 individual exposures in a sequence. They are ideal for dodging and burning, or timing film development and other darkroom processes.

F-Stops Exposure Plans: These are designed for f-stop printing. They support a base exposure in units or time, and then up to 15 additional exposures calculated in f-stops. For example, an f-stop exposure plan configured as 5 seconds followed by 0.5 stops, 0.1 stops, and 1.0 stops would give four exposures: 5s, 2.1s, 0.4s and 5s.

Calibrating Sensors

The new universal sensor, plus the older UV and visible light sensors can be calibrated in the Control Panel screen. You can get there by sliding left from the starting screen.

New with the LC6: Sensor calibration is now stored on the sensor rather than in the light integrator. This means that you can move the light integrator between different light units without losing sensor calibration data.

New with the LC6: Sensors and other peripherals can be individually enabled and disabled. This means you can choose which to use for each exposure.

Sensors are calibrated individually:

  1. Move to the Control Panel screen
  2. Select the sensor by touching its button. These buttons match the USB-A connector position. Make sure the sensor is enabled (first command button).
  3. Sensor-specific information, including current measurements and calibration value will be shown below the buttons.
  4. Touch the calibrate command button (third position) to move to the Calibration screen.
  5. Touch the confirm command button to start automatic calibration. Alternatively you can delete the stored calibration value by touching the trash command button (first position), or you can manually assign a calibration value using the edit command button (second position).
  6. The LC6 will automatically calibrate the sensor.

After calibration, one unit of light will be approximately one second of time at peak light intensity. The calibration value reported in the Control Panel screen is the average light intensity measured during the calibration process.

At the end of the automatic calibration process, the LC6 will report the 'afterglow' it detected from your light source. This is the amount of light that was detected after the light source was switched off (assuming you are using a power controller). This can help you to understand, and allow for, the afterglow when making very short exposures.

Configuring Universal Sensors

Also on the Control Panel screen, you can configure the new universal sensor. This can be switched to measure either UV light or visible light. It can also be given a measurement threshold, below which any detected light is ignored. This is useful in situations where your light unit is not completely light tight.

Configuring New Power Controllers

The new power controllers can be configured for a range of different functions.

  • Starting/stopping the lights when exposures begin/end
  • Starting before exposures and stopping after exposures – e.g. for controlling vacuum frames
  • Starting/stopping based upon temperature sensor measurements – e.g. for controlling cooling fans
  • Starting/stopping based upon humidity sensor measurements – e.g. for controlling humidifiers

Each configuration can be triggered before/after each exposure in the exposure plan or before/after the exposure plan itself. For example, you can have one power controller that switches on the vacuum frame 20 seconds before the first exposure in the plan, and switches off after all exposures in the plan have completed. Another power controller can switch the lights on and off with each exposure in the plan.

Older smart power controllers cannot be configured. these will automatically start and stop at the beginning and end of each exposure in the exposure plan.

Firmware Updates

It is easy to update the LC6 firmware. Here's how:

  1. Some firmware updates may need to reset the system settings, including presets and exposure plans. Please write these down before starting so you can re-enter them afterwards.
  2. Download and unzip the firmware UF2 file.
  3. Connect the LC6 to your computer via the USB-C connector on the rear panel.
  4. Switch on the LC6 and swipe left twice to move to the System Information screen.
  5. Press the second command button (the one with a microchip icon) which will open a page of update instructions. Press the confirm command button.
  6. The display will go black, and the LC6 will reboot into firmware update mode. In a few seconds it should appear on your computer as a USB drive called RPI-RP2.
  7. Drag and drop the firmware UF2 file onto this USB drive. It will automatically install itself on the LC6. DO NOT INTERRUPT THIS STEP OR YOU MAY LEAVE THE LC6 INOPERABLE.
  8. Once the new firmware has been installed, the LC6 will restart. The update is now complete. Your computer may complain that the USB drive has been improperly removed, but you can ignore this.
  9. If you are returning to an older firmware version then I strongly recommend doing a manual factory reset using the first command button on the System Information screen.
  10. Switch off the LC6 and disconnect from your computer.

If you want help doing this, then we can have a video call so I can talk you through the process.

Firmware Change Log

Version Summary of Changes
v0.3.1 BETA 1 [download] Initial beta test version
v0.3.4 BETA 2 [download]

Naming Presets: Now you can name presets. The name can contain up to 12 letters, numbers and spaces.

Metronome and Countdown Beeps: The metronome now has six settings – off, 1s, 5s, 10s, 30s and 60s. Countdown beeps at the end of the exposure now have six settings – off, last 5s of the exposure, last 10s, 15s, 30s and 60s.

Improved Settings Screen: The settings screen has internal performance and stability improvements.

Manual Calibration: An issue with the manual calibration screen when editing a very large calibration value has been resolved. The calibration value can be from 0 (not calibrated) to 9,999.999 µW/s.

IMPORTANT: This firmware version changes the structure of the saved configuration settings. When installed, it will reset your configuration settings, presets and exposure plans.

v0.3.5 BETA 3 [download]

Power Controller Configuration: Power controllers can now be configured to switch on/off after an exposure has started.

Universal Sensor Configuration: An issue that in certain circumstances caused universal sensor configuration errors has been resolved.

IMPORTANT: When installed, this firmware version will reset your configuration settings, presets and exposure plans.

v0.3.8 BETA 4 [download]

Calibration: The calibration process starts by reading ambient light. It uses this to calculate a reasonable threshold value for the sensor. You may manually change this value afterwards if you want.

Calibration: The afterglow is reported in seconds and units. For example, my De Vere 504 has an afterglow lasting 0.7 seconds and producing 0.2 units of light. This is valuable information if using very short exposures.

Calibration: An issue that stopped the threshold being updated properly in v0.3.7 has been resolved.

IMPORTANT: This firmware version does not reset your configuration settings, presets and exposure plans after installation. If you are upgrading from v0.3.1 then you must do this manually afterwards.