Light!

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This article originally appeared in Ballooning Magazine, March-April 2011…

There’s an old saying in business that nothing happens until somebody sells something.

The equivalent in photography is there is no photo until light happens.  Light is everything.  A photographer is an interpreter and manipulator of light.  The more you know about light, the more you understand how to work with it, how to play with it and how to coax something artistic from it, the better your photographs will be.

Erie Town FairExplaining the underlying physics of light is beyond the scope of this article.  But when discussing light in the context of cameras, it simplifies the discussion to think of light as made up of very, very tiny colored particles.  Physicists call these particles ‘photons’.

In this simplified explanation, think of your camera, whether digital or film, as a light collector.  In a digital camera, light enters through the lens and focuses on a specialized electronic device called an image sensor.  The job of the image sensor is to convert a count of the number of photons and the color of the photons that arrive at its surface at each location across the sensor.  Individual light-collecting locations on a sensor are called ‘photosites’.  Again in our simplified discussion, you may have heard photosites described as ‘pixels’.  A camera with an image sensor of 10 million such photosites might be referred to as a 10 megapixel camera.

The human eye is also a camera.  Although similar to digital cameras in this regard, combination of human eye and human brain is much more sophisticated than the combination of image sensor and processing electronics inside your digital camera.  You can prove this point by performing the following test.

Kids agree - ballooning is FUN!Walk into any room in your home when the sun shines through the window.  Turn off any lights and look at the wall that contains the window.  In this ‘scene’, you are able to see detail in the shadows of the darkened room, as well as see detail outside through the window of objects that are lit by the sun.  There is a large difference in brightness between the darkest parts of the room and the brightest parts of the outdoor view, but your eye-brain combination is able to discern details in both areas at the same time. 

Now, try using your digital camera to capture the same ‘scene’ in a single exposure with the same degree of detail in both dark and bright areas.  It won’t happen.

Your camera will be forced to choose between light and dark.  If you allow the camera to auto-expose for the room’s interior, it is likely that the view out the window will turn into one bright smear of white.  If you allow the camera to auto-expose for the bright window view, the interior of the room will become deeply shadowed or black.

The term ‘dynamic range’ refers to the difference in light from the darkest shadow to the brightest highlight.  Compared to the eye-brain combination, cameras are still very limited in their ability to capture a wide dynamic range with a single exposure.

This revelation brings us to the main point of this article:

The best color balance and exposure in a photograph occurs when the difference in light levels – the dynamic range – is minimized.  Try to compose your photo so that all the important elements in the scene are either fully lit or fully shaded.

Snowmass Village Balloon Festival

In the hundreds of ballooning photos I see each month, more photos suffer from washed out colors and milky gray skies than any other single problem.  This often stems from forcing the camera to auto-expose in the shaded areas of an outdoor scene.  This blows out most of the highlights and turns pretty blue sky into gray haze.

The typical ballooning photo is taken outside during the day where the sun provides the primary source of light.  While the pilot is concerned with wind direction, the photographer is concerned with the direction of sunlight in relation to the direction of the photo.  To minimize dynamic range when direct sunlight is the primary light source, position yourself with the sun to your back or at a slight angle to your back.  This will cause the large shadows in the scene to fall behind the subjects.

Red Rocks Balloon RallyShooting with the sun at a slight angle to your back will cause the shadows to fall behind and slightly to the side of the objects.  If your composition includes balloons standing or in flight, shadows will fall along the load tapes, gore and panel edges, and small ripples in the fabric.  These slight shadows will give the balloon more of a three-dimensional appearance than if the light were coming from directly behind.

One problem with positioning yourself with your back to the sun is that most people instinctively stand so they don’t have to look into the sun.  When the sun is on your back, chances are that you will see the backs of the people in the scene, not their faces.  You may have to move to one side or the other to avoid a ‘posterior composition’ and use flash to help fill any shadows on faces.  You can often get people to look at you and smile – even if they have to turn towards the sun – by shouting a hearty ‘Hello there! Great day, isn’t it?”

Since this is art, rules are made to be broken.  High contrast scenes are often appealing when foreground silhouettes tell a story against a bright background.  These photos capitalize on the dynamic range limitation of the image sensor.  One tip for great silhouettes of people is to shoot up at them from a lower angle.  This reveals the full human form against the background.

As a rule, ballooning photographs are taken outside.  Light sources illuminating the scene include direct sunlight, sunlight filtered through clouds, sunlight scattered by a dark sky or surrounding objects and terrain, flame from the burner, vehicle headlights, street lights, flashlights, etc.  In our next installment, we’ll examine how the color of light from these sources plays a role in your balloon photography.

 

 

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