/
2 - Spectral Sensitivity Color Calibration

2 - Spectral Sensitivity Color Calibration

Owned by Former user (Deleted)
Last updated: Jan 20, 2017 by John Medalen

Input arguments and calibration per iteration

This calibration method is only available for some sensors. The Spectral Sensitivity Color Calibration tab is disabled if the selected sensor is not supported.

Input arguments

IR filter transmittance data [Required]

The data file should be a text file with two columns of numbers, the wavelength in nm, and the transmittance percent. Example:
360 3.79
370 4.08
380 23.72
390 80.95

Lens transmittance data [Optional]

SensorTune uses internal sensor sensitivity and lens transmittance data, but you can load your own data optionally.The spectral data should be in the following format:
wavelength, relative response red, relative response green, relative response blue ...

Sensor sensitivity data [Optional]

SensorTune uses internal sensor sensitivity and lens transmittance data, but you can load your own data optionally.The spectral data should be in the following format:
wavelength, relative response red, relative response green, relative response blue ...

Simulated Image [Optional]

An image can be loaded in order to visualize the calibration effect.


Calibration iterations

Using More settings..., make sure that Use measured gain is unchecked.

  1. Run the calibration and save the result in INI file.
  2. Under the "warm" color temperature in use in SensorTune (defaulted to 2500K), apply the settings acquired in the previous step to the sensor and capture the image. Measure the color ratios of Red/Green and Blue/Green of neutral patch in the Macbeth chart. IQWare with Macbeth color checker chart can be used for this purpose. IQWare reports color ratio as well as AWB errors associated with the image. Choose one set of ratios reported to be used as "Measured gain". If there is no clipping in the image, a set of mean ratio can be used. Otherwise, choose the ratios from the middle level patches.
  3. Repeat the same step under "cool" color temperature (defaulted to 6500K).
  4. Enter the selected color ratios in "More settings" and re-run the calibration with "Use Measured Gain" checked.
  5. Verify the tuning quality by capturing image with new settings and running in IQWare. This verification should be done under different color temperature range.
  6. If the result is not satisfactory, re-adjust the ratios and repeat the process.

Related content