Sunday, January 31, 2016

How to Photograph Reflective Surfaces

Photographing reflective surfaces and objects is usually quite challenging, and can easily turn the work of the photographer into a frustrating task.

Reflections are a hard to tame beast, but it gets easier to control if you know the rules. So, in this article I will show you how to create a high impact image with controlled reflections, like the one below, with a really simple, but highly effective, technique and using equipment you most certainly already own.

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A reflective surface acts like a mirror reflecting light, so if the light source of your image comes from the same direction as the camera, it causes specular highlights resulting in blown out spots without texture, and an overall poor looking image like the following one photographed with the flash mounted on camera.

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It all comes down to the basic principles of light and the way it behaves, which is in fact very predictable. The law of reflection explains this phenomenon. If you project a ray of light on a flat reflective surface like a mirror, then the angle of incidence equals de angle of reflection, like the following diagram illustrates:

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So, physics apart, what this really means is that if you are trying to photograph a reflective surface you should never light it from the same angle as the camera, otherwise you will only get light bouncing straight back at you (depending on the angle of the object).

The trick here is to use a big light source, and position it in the same opposite angle of your camera, in relation to the photographed object (behind it).

You can do this with a studio flash head and a big softbox, but there is a much simpler and cheaper way of doing it. You just need some white cardboard, a flash, and trigger system to fire it off-camera.

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Here is how you can use this lighting setup:

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The light from the flash bounced off the cardboard is a much bigger light source, allowing you to control the reflections on your image, creating gradients that shape the object, and avoiding specular highlights. Notice it also creates texture on the rock background.

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This simple technique allows you to create a lot of different lighting effects in your image, depending how you position your flash, and angle the cardboard in relation to the photographed object, which also creates texture on the background stone and water drops.

Here are some examples of light variations on this imag,e with just some small adjustments to the cardboard positioning.

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Knowing that light rays will always bounce from a reflective surface, at the same angle at that at which they strike it, makes it possible to determine the best positioning for the camera and the light source, taking into consideration the family of angles as you can see in the next diagram.

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The light positioned within the family of angles will produce a direct reflection and the light outside of the family of angles will not light a mirror-like subject at all, from the camera’s point of view.

Even though the reflections on these images are not direct, but rather diffused reflections (which makes difficult to calculate the light angle as it is being bounced and dispersed in different directions) the family of angles can give you a good estimate of how to position your light in relation to the camera angle, in order to control the reflections in your image.

All this technical information about light physics may seem overwhelming at first, but it will all make sense when you start playing around with it. So, give it at try, I’m sure you will get great images. Please share any questions and your images of reflective objects in the comments section below.

The post How to Photograph Reflective Surfaces by Ivo Guimaraes appeared first on Digital Photography School.

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