Semi-Automatic Brightness Adjustment by Geolocation

In versions 2.4, the ambient-light-level slider has been combined with an estimate of local solar-illumination to achieve semi-automatic brightness control throughout the day. Adjusting the slider sets the ratio between indoor-illumination and outdoor solar-illumination - the Daylight-Factor (DF). Should circumstances change, adjusting the slider updates the ratio. (Solar-illumination is estimated for a location by using the local date-time to determine sun-angle, and from that, estimates for illumination, and air-mass.)
Each display's brightness is periodically updated by matching the estimated indoor-illumination against each display's custom lux-brightness-response profile.
How to enable it
- Settings Dialog: set your geographic location ➀.

- Light Metering Dialog: check that the light-meter ➁ is set to Semi-automatic geolocated (it's normally the default). If you haven't already done so, setup Lux Brightness Response Profiles for each display ➂. Older displays, with weak back lights, can be given relatively flat profiles, perhaps varying from 80% to 100% ④. Newer displays, with HDR capable back lights, can be given stepper profiles, possibly varying from 10% to 100% ⑤.
How to use it


- Set the prevailing indoor light level using the ambient-light-level slider ➀.
- If not already enabled, click the sun icon to enable automatic adjustments ➁.
- Starting from your chosen level; the application will periodically update ambient-light-level ➀ in proportion to the expected outdoor sunlight (the adjustment period is set in the Light Metering Dialog).
- If conditions change, adjust the ambient-light-level slider ➀ to establish a new ratio of indoor to outdoor illumination.
The Light Metering Dialog live plots the current indoor and outdoor (Eo) illumination estimates ➂, along with the set Daylight-Factor.
A Daylight-Factor value can optionally be saved in a Preset. For example, you could use the Preset Dialog to set up Cloudy-DF and Sunny-DF Presets. The DF can be the only thing in a preset, you need not include any display controls or features.