The Minnaert Project

1. The Minnaert Project A Visual Approach By: Xijia Chen

2. The Book and The Project • The Book • M.G.J. Minnaert’s: Light and Color in the Outdoors • Scientific explanations for multiple lighting phenomenon • The Project • Purpose: To capture examples of the above-mentioned effects in order to demonstrate and compliment his descriptions • Reason: A picture is worth a thousand words

3. Equipment Used & Places Traveled • Digital Camera: • Kodak DC280 • Places Traveled • Stanford University, Stanford, CA • Shoreline Park, Mountain View, CA • Foster City, CA • Fisherman’s Wharf, San Francisco, CA

4. Reflection by the Clouds • Characteristics of Clouds – p.324, Section 235 • Dazzling white where sun illuminates them • Gray underneath as they pass overhead • Opaque white body -- light reflected by numerous droplets of water • “Silver lining” if sun is covered by cumulus cloud • Often vivid colors during sunrise/sunset Shoreline Park, CA Shoreline Park, CA

5. Shadows • “When you look at your shadow on the ground, you will notice that the shadow of your feet is clearly defined, whereas that of your head is not. The shadow of the bottom part of a tree or post is sharp, while that of the higher part part becomes increasingly unclear toward the top.” – p. 4 Stanford University, CA • Notice near the base of the lamppost, the shadow is distinct and mostly consists of the umbra, whereas at the bulb, the penumbra is more visible and the shadow is much less crisp.

6. Shadows (continued…) Stanford University, CA • Notice that the spokes at the bottom of the tire are slightly visible whereas those at the top are not due to the merging of the penumbra and umbra. This is another example of the gradation from clear to blurry shadows.

7. Differences Between an Object and It’s Reflection (Part 1) • “…the reflection of a scene in calm water resembles the scene itself upside down. Nothing could be further from the truth…The reflection of a bank sloping towards a river appears shortened…” – p. 11 El Camino Reale, Stanford, CA • Notice that the distance from the real car and brown hill to the curb (marking the horizon) seems larger than the distance from those objects to the curb in the reflection

8. Differences Between an Object and It’s Reflection (Part 1 …continued) • Explanation – Although the object and it’s reflection are identical, their positions are different, therefore the perspective of the viewer w/ respect to each is shifted differently:

9. Differences Between an Object and It’s Reflection (Part 2) • “Clouds are never as beautiful as when they are reflected in a mirror” • P. 13 • The reflection of clouds in the water is clearer than the clouds in the sky.” • P. 20 Shoreline Park, Sunnyvale, CA • Notice whereas the sky is almost white, the clouds in the canal are fairly distinct

10. Differences Between an Object and It’s Reflection (Part 2…continued) • Explanation: Mostly psychological • The reflected view always associated as being in a plane • ‘framing’ of the picture results in uncertainty about the position, giving an impression of relief • Protects our eyes from brightness of directly looking at the sun • Polarization of reflection = luster attenuated and colors saturated

11. Freak Reflections • “A row of houses throws a dark shadow on to the road, but in the middle of this you often see spots of light…it is reflected by the windows of the houses on the other side of the road.” – p. 15 Stanford University, CA • Although all of these surfaces were in shadow, they each exhibit one or more bright spots due to reflections from opposing windows.

12. Reflections in Soap Bubbles • “Try blowing soap bubbles…The side turned toward us…shows the same upright images as the spherical mirror,…the inside back…inverts the images.” – p. 21 • “The magnificent shades of color, the changing tints…” – p. 21 Stanford University, CA • In the left bubble, both the ceiling light, bubble wand and their respective inverses can be seen. Although the right bubble only shows the ceiling light, the striations of the rainbow colors can be faintly seen.

13. Window Glass vs. Plate Glass • “The reflections from windows indicate whether they are of normal window glass or plate glass: if the latter, the images are fairly clear, if the former, they are so irregular that the uneveness of the glass can be seen clearly” – p.22 Rengstroff House, Foster City, CA Shoreline Park • Notice how the image in the left window is almost a mirror reflection, whereas the cars in window on the right curve upward and then back down

14. Irregular Reflections by a Slightly Rippled Surface (Part 1 – Houses) • Dominance of Vertical Lines in Reflections • “…A chimney or a thin mast is reflected clearly, but the strong lines of the roofs have disappeared: only the vertical lines are found back in the reflections.” – p. 24 Foster City, CA

15. Irregular Reflections by a Slightly Rippled Surface (Part 1…continued) Foster City, CA • Notice that in both pictures, the vertical lines of the chimney are strongly apparent whereas the horizontal lines are blurry and indistinct

16. Irregular Reflections by a Slightly Rippled Surface (Part 2 -- Streetlights) • Vertical Columns of Light (Streetlights) • “Observing a streetlight at night gives us the ‘elementary phenomenon’…an upright line, the columns are neatly stacked together and magnify each other; … a horizontal line, they lie side by side and broaden the line to a hazy surface.” – p. 24 Fisherman’s Wharf, San Francisco

17. Irregular Reflections by a Slightly Rippled Surface (Part 2…continued) Fisherman’s Wharf, San Francisco • In both pictures, the reflection of the streetlamps are stretched in the vertical direction. Since the water is slightly rippled, each wave reflects a separate image, gently adding up to an elongated column that remains vertical in the plane of our eyes regardless of whether the lamps are actually in the plane of the page (previous page -- the lamp on the left) or tilted out of the plane of the page (previous page -- the row of lamps on the right). This verticality is sometimes affected by factors such as wind, etc.

18. Closed Light Coils • “Remarkable is the appearance of closed coils of light seen when the water surges gently, the waves have short crests, and the light source is high.” – p. 31 Shoreline Park, CA • Explanation: If you look at the water at a large angle, the light is reflected by two separate spots of light on each wavelet. By looking left or right, the reflections will appear to get closer together until they fuse into the closed irregular annulus that you see.

19. The Shifting of Reflected Images Toward the Horizon • “The reflection of the sun in the waves is a dazzlingly bright patch, which, as the sun sets, is more or less triangular in shape, showing a shift towards the horizon.” – p. 35 Foster City, CA Shoreline Park, Sunnyvale, CA • Notice that the photo on the left (taken towards sunset at high wind) has a triangular reflection whereas the reflection in the photo on the right is very obviously a vertical column

20. Stained-Glass Windows • “Even the most brightly colored stained-glass windows look dull when seen from the outside.” – p. 124 Stanford University, CA • Whereas from the outside, the stained-glass looks somewhat dull and dark because the light is reflected and the light coming from inside is faint, from the inside, the colors burst to life due.

21. Scattering of Light By Clouds • “Certain kinds of cloud obscure the sharp outline of the sun until only a round mass of light remains that grows fainter towards its periphery.” – p. 283 San Francisco, CA • By blocking the sun’s disk, the cloud has obscured the sun’s light exactly as Minnaert’s book describes. Even more intriguing are the distinct “rays” or “bands” of sunlight that emerge from the clouds, tracing a clear path across the sky.

22. Refraction by an Undulating Water Surface • “When a water surface is not perfectly smooth, this is revealed by a change in direction of broken rays of light and an uneven brightness at the bottom.” – p. 46 Stanford University, CA • The brightness of the water is obviously uneven in this fountain behind The Memorial Church. Clear patches of bright white interspersed with darker colors illustrate the “broken rays of light” effect.

23. The Colors of Sunset • “The light that we see at sunset in the direction of the sun has the blue component removed, so that we see a red sun.” – Plate 35 San Francisco, CA • The scene around Alcatraz at sunset is tinted pink because of the scattering of blue light due to the longer distance light has to travel through the atmosphere in order to reach our eyes.

24. Miscellaneous: • Distant houses only reflect the light of the rising or setting sun – p. 10 San Francisco, CA

25. Fin