Keely Hill

On Indoor Lighting

Designing my lighting environment for mental wellbeing and subconscious separation of activities.

Lighting design is spatial and temporal. Throughout my day I employ different color temperatures at different lighting sources around my living and working environment.

Colored graphic showing sunrise and sunset times using color on longest and shortest days of my location's year. Below, a similar gradient showing the alignment of lighting color temperatures described in this post.

Sun versus my indoor lighting throughout the day.


I am able to awake with natural sun light. The blinds are usually closed but sunlight still gets through. Once conscious and out of bed, I rotate the vertical blinds to an open position. The window is on the west, so the sunrise and early daylight is diffuse.

When I cannot rise to the sunrise, be it appointment or schedule, I first turn on a bedside lamp to a warm white (~3000K ), then the half-covered brighter soft white (~4000K ) disk ceiling fixture over the course of a few minutes as I get dressed.


Mornings involve simply opening the east facing vertical blinds and letting the sunlight pour in. On the rare cloudy day, I may use a soft white corner desk lamp for a few hours before the next transition.

Late Morning to Early Afternoon

On work-from-home mornings and early afternoons, I turn on a 4 foot(122 cm) long daylight (6500 K ) diffused LED fixture that I have stuffed into the “head jamb” of the window. This maintains the illusion of sunlight in my desk area once the sun passes overhead; especially during the winter season. I often find that it completely tricks my brain when I look outside and see a dark cloudy day.

When I’m off or it’s the peak of summer, I may or may not use the daylight strip. I think of it as my “productivity light”.

Late afternoon

When I feel that the work day’s end is in an hour or so, I turn off my “sunlight simulator” and turn on a similarly colored, but slightly lower temperature ceiling light in the kitchen (if it’s not on already). The source from several meters behind me smooths the room’s illuminance. As sunset begins, the soft white table lamp turns on too.


The light in the kitchen provides a smooth transition to making dinner if it is dark outside. The next lighting change is a 2 meter floor lamp with a tall amber (< 2400K ) bulb sitting in an inverted conical shade for diffusion off the ceiling. It starts at full brightness, then I slowly bring the tabletop dimmer it to it’s minimum as my evening progresses. And eventually, off. The soft white table lamp is turned off with the first dim of the floor lamp.


Amber nightlights , all placed below chest level and some further dimmed with tape, provide very subtle light around the flat during sleep time. No lights are on in the bedroom.

Computers and Transitions

My various computer screens have some version of time-based blue removing color shift enabled.

Nothing about this lighting design is computerized, everything is on some kind of standard mechanical switch. It would be neat to automate these transitions, but the times of the transitions often are based on season, cloud cover, and personal feeling. The manual strategy is simple and flexible.


A surrounding environment without outdoor light trespass is important. See the following for information about light pollution. Luckily, it’s fix provides instantaneous benefit.

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