Light and time of day

Learning goal

You will be able to find in advance between which hours a building's facade catches direct sun, working it out from the direction the facade faces and the season. You will take into account that the same facade catches light at different hours in summer and winter, and that even a north-facing facade sees the sun for a short time on summer mornings. You will read how the shadows falling in window recesses and under eaves and moldings show the facade's depth, and wait for these shadows according to the sun's height. You will plan the blue hour after sunset, when the building's own lights come on, and choose a white balance between the warm color of the floodlighting and the blue of the sky. You will keep a face standing in this warm and cool mix in its own tone, by looking at which light is lighting it.

The question

Your friend had first photographed the brick apartment building on Saturday morning; the facade was in shade, the bricks pale like tile dust, the window frames flat white smudges. Coming home from work on Tuesday late afternoon, they pass the same street and stop short: the sun is striking the facade at a slant, the edge of every brick a separate line, a sharp shadow under each window frame, the bay window as if it had stepped out of the facade. The same building, the same street; only the time has changed. They decide to come back at that hour the next day and shoot again, but on their evening walk, when the apartment building's windows light up, they are surprised once more. At what time of day does a building look its best?

Context

In your first step into architecture you learned that the direction a facade faces decides at what time of day that facade will catch the sun (Lesson 16.4). In landscape planning you saw that the arc the sun draws in the sky shifts with the season and that this can be read in advance with a map (Lesson M.2). In city nights you also caught those few minutes after the sun goes below the horizon when the lamps and the sky come to the same brightness (Lesson G.2).

This lesson applies these three pieces of knowledge to a single building. A photographer going to a building has two variables: the facade's direction doesn't change, but where the sun is changes from hour to hour and from month to month. Someone who reads these two together can know what the building will look like without going there. The question isn't declaring one hour "the best"; it is finding which light carries the building's idea.

Simple explanation

When does the facade catch the sun?

Façade sun window is the span of time when a facade catches direct sun, when the sun can strike the facade from the front or from the side. As long as the sun is in the half circle in front of the facade, the facade is lit; the moment the sun passes behind the plane of the facade, the facade falls into shade. The start and end of the window are the moments when the sun strikes the facade most slantwise.

This window shifts with the season. At Türkiye's latitudes the sun rises in the northeast and sets in the northwest in summer, while in winter it rises in the southeast and sets in the southwest. The result is surprising: a north-facing facade sees the sun in June from early morning until around nine, and for a short time after five in the late afternoon, while in December it never sees it. A south-facing facade catches a low, slanting sun all day in winter, while in summer the noon sun comes almost from overhead, at an angle close to parallel with the facade. The same building can therefore look as different as a seasonal series; finding the sun window from a sun map makes it easier to choose the day and hour to go.

What do shadows add to the facade?

A relief shadow is the shadow falling in window recesses and under eaves, balconies and moldings that shows the facade's depth. In a flat photo, how recessed and projecting a facade is can be understood only from these shadows. When the sun strikes the facade straight from the front, the shadows hide inside the recesses and the facade flattens as if printed on card. As the sun slides to the side or up, the shadows lengthen; a short relief shadow tells of a thin molding, a long shadow of deep eaves.

Which shadow tells a building better depends on its idea. A facade with deep stone carvings comes alive in side light; a flat, colored facade, on the other hand, can be broken up by hard shadows and can show the color of its material more honestly in the even light of open shade. A cloudy day is therefore not always a loss either. A glass facade, meanwhile, lives more by reflection than by shadow: it carries the sky or the buildings opposite, and that reflection changes with the hour too.

How is the building read at blue hour?

Architectural floodlighting is the lights placed on the outside of a building so that it can be seen at night, often striking from below upward and warm in color. At blue hour these lights and the windows lit inside meet the deep blue of the sky in the same frame. At this time the sky reads as a surface separate from darkness, the building's silhouette is clear and the life inside is visible through the windows.

The color of this light calls for a decision. If the white balance is set for the floodlighting, the stone is neutral and the sky deep blue; at a setting close to daylight, the stone shifts to orange and the sky to a lighter blue. Both can be right; how much this contrast between warm and cool will show is your choice. Floodlighting striking from below turns the relief shadows upside down: the shadows now fall above the moldings, and the building shows a different face from its daytime one.

If there is a person in the frame, look at which light is striking their face. A face lit by the cool light of the sky can stay gray and pale even with a warm white balance; on dark skin this can make the warmth vanish entirely, while on light skin it can lead to a purplish coldness. Stopping the person close to the light of a shop window or an open door gives their face a light the same color as the building.

Visual evidence

Your friend looks at a sun map on their phone: the apartment building's facade faces northwest; in mid-September the sun turns onto the facade only a little after three o'clock and strikes it slantwise from the west until sunset. Why the facade was pale on Saturday morning is now clear.

On Wednesday late afternoon they come at that hour. The sun licks the facade from the end of the street; under each window frame there is a relief shadow a hand's span long, the lower edge of the bay window casts a dark line on the facade, the joints between the bricks stand out. They shoot from the opposite sidewalk, holding the camera level.

The sun sets, the street turns gray. About twenty minutes later the windows light up one by one and the shop window of the bakery on the ground floor fills with an orange light. They set up the tripod and, keeping the white balance close to the bakery's light, make an exposure of a few seconds: the sky deep blue, the brick warm brown. The baker, a young man with olive-brown skin, comes out of the door with a tray. They ask permission and call him to stand still for a few seconds in front of the shop window; the window light lights one side of his face, and the trace of flour on his forehead and the copper tones of his skin read. In the first attempt, though, where he stayed in the sky's light in the doorway, the same face had turned ash gray.

Common mistakes

Summary

A facade catches direct sun in a certain facade sun window, according to the direction it faces and the season's sun path; this window can be found in advance with a map. Relief shadows tell the facade's depth, while floodlighting gives the building a different face at blue hour; which hour to choose is not a rule but a decision about which light serves the building's idea.

Mini assignment

In this assignment you will photograph a single building in three different lights and compare.

1. Find which direction the facade of a building near you faces, and work out its facade sun window for this season from a sun map.
2. Photograph the building from the same place: inside the window while the sun strikes the facade slantwise, outside the window while the facade is in shade, and at blue hour after the windows have lit up.
3. Add to the blue hour frame someone who lives or works in the building, with their permission, close to a warm light.

Check yourself

• In the frame you shot in slanting light, which detail of the facade did the relief shadows bring out?
• In the blue hour frame, how does the white balance you chose show the stone and the sky?
• Which light is lighting the face in the frame, and is it in its own tone?

Glossary

Mini quiz

1. What does the facade sun window depend on?

• A) The facade's direction and the season's sun path
• B) The building's height
• C) The lens's focal length
• D) The camera's ISO value

2. At Türkiye's latitudes, in which period can a north-facing facade see direct sun?

• A) At noon in winter
• B) Never
• C) In the early morning and late afternoon hours of the summer months
• D) Only at noon on the spring equinox

3. Why does the facade look flat when the sun strikes it straight from the front?

• A) Because the light is very warm
• B) Because the relief shadows hide inside the recesses
• C) Because the sky goes dark
• D) Because the white balance is off

4. What can be done for a face left in the sky's cool light at blue hour?

• A) The exposure time is shortened
• B) The white balance is set to the coolest setting
• C) The person is pushed to the edge of the frame
• D) The person is brought close to the warm light of a shop window or a door

Answers

1. A — Direction and season together decide when the sun enters the half circle in front of the facade.
2. C — Because in summer the sun rises in the northeast and sets in the northwest, the north facade catches the sun for a short time.
3. B — Light from the front removes the shadows that show depth, and the facade flattens like a surface.
4. D — A face coming close to warm light is lit in the same color as the building and its tone doesn't stay pale.

Summary card

• Facade sun window: direction + season; find it in advance with a map.
• Even a north facade sees the sun briefly on summer mornings and evenings.
• Relief shadows tell depth; light from the front flattens the facade.
• At blue hour floodlighting gives the building a different face; the white balance is your decision.
• Don't leave a face in the cool sky light; bring it close to a warm light.

Bridge to the next lesson

Enlarging one of the frames shot in late afternoon light on the screen, your friend gets caught not by the apartment building as a whole but by a corner: the bond of bricks laid one after another, the sharp line of the shadow under a window frame, the cracks in the bay window's wood. When they tighten the framing and leave only that piece, the frame starts to tell something else. Can part of a building be stronger than the whole? The next lesson takes up leaving off showing a building whole and coming closer to abstraction by isolating its pattern, its line and its texture.