On-camera ring flashes are more commonly used by macro photographers or for scientific purposes (you’ll sometimes see crime-scene photographers shooting with a ring flash on TV!). You mount an on-camera ring flash to the front of your lens, then you can easily carry the entire setup into the field (to photograph insects and flowers or, yes, dead bodies). Because a ring light sits on the end of the lens, there’s no concern about the camera or lens barrel casting shadows on your subject, and it lets you shine light in dark, shadowy places.

When a beam of light strikes the interface between two media it changes direction, and the amount of change is dependent on n. If the angle of incidence is ​_θI​, and the and the angle of refraction is ​θR_​, the ratio of angles is given by ​Snell's Law​:

Dispersion

You've no doubt seen a rainbow, and you may be wondering why you can only see them when the sun is behind you and you're at a particular angle to the clouds or to a rain shower. Light does refract inside a water droplet, but if that were the whole story, the water would have be between you and the sun, and that's not what typically happens.

It’s time to get a bit experimental – and have lots of fun with ring lights in the studio! Starting with option number one:

Polyprism

Deziel, Chris. "What Causes The Dispersion Of White Light?" sciencing.com, https://www.sciencing.com/causes-dispersion-white-light-8425572/. 27 December 2020.

The denser the medium, the slower the beam travels. The ratio of velocities of incident (vI) and refracted (vR) light is a constant (n) called the index of refraction for the interface:

Diffraction is a phenomenon that occurs when light passes through a very narrow slit. The individual photons behave like water waves passing through a narrow opening in a seawall. As the waves pass through the opening, they bend around the corners and spread out, and if you allow the waves to strike a screen, they will produce a pattern of light and dark lines called a diffraction pattern. The line separation is a function of the diffraction angle, the wavelength of the incident light and the width of the slit.

Prism

The controversy eventually resulted in the compromise that light is both a wave and a particle. This understanding wasn't possible until the introduction of quantum theory in the 1900s, and for almost 300 years, scientists continued to perform experiments to confirm their point of view. One of the most important involved prisms.

A ring light is a simple, relatively inexpensive way to get started with studio photography – and with the right approach, it can look really, really good. Here are just a few photos I’ve taken using a ring light:

is a visionary artist and philanthropist in Portland Oregon. Her work includes wedding photography www.BrideInspired.com and leadership with www.RevMediaBlog.com.

In this article, I’m going to take you through all the ring light basics. I’m going to explain what a ring light is and how to use it. Then, for those who are interested in more advanced ring light applications, I’m going to share five unconventional approaches (such as using a ring light as a prop).

Because the power output on your flash is not affected by shutter speed, you can drop the shutter as low as you need to make this work. You may want to use a tripod for really slow shutter speeds, though.

A little warning: If you’re a technically-minded photographer, you’re probably going to hate this tip, as the results tend to be a little soft. Also, while dragging the shutter can be used for some striking photos, you still have to be careful with controlling the movement of your camera.

For an even more experimental approach, you can try using the ring light as your primary light source and your strobes as fill. To make this work, however, you’ll need to take the strobe power way down, so make sure the power on your strobes can drop that far before committing to the technique.

Visiblelight

Dragging the shutter is a fun technique that can result in beautiful photos, but it generally involves the use of both a flash and some ambient light.

The fact that a prism disperses white light forming a spectrum could be explained by both the wave and corpuscular theory. Now that scientists know that light is actually composed of particles with wave characteristics called photons, they have a better idea of what causes light dispersion, and it turns out it has more to do with wave properties than corpuscular ones.

Off-camera ring lights, which attach to an external light stand, offer a wide band of illumination, and include a large aperture into which a camera can fit. This is the type of ring light featured throughout the article.

While ring lights are powerful, your strobes will probably blow them out of the water if left unadjusted, so set the power (both on the strobes and on the ring lights) accordingly.

The light from the sun has a downward trajectory. Light can exit from any part of the raindrop, but the greatest concentration has an angle of deviation of about 40 degrees. The collection of droplets from which light emerges at this particular angle form a circular arc in the sky. If you were able to see the rainbow from an airplane, you would be able to see a complete circle, but from the ground, half the circle is cut off and you only see the typical semicircular arc.

By the way, continuous ring lights offer a major bonus for portrait photographers: Because the output is constant, your subject’s pupils get constricted. That way, you’ll see more of the color of their eyes in your photos – which generally looks great!

Deziel, Chris. (2020, December 27). What Causes The Dispersion Of White Light?. sciencing.com. Retrieved from https://www.sciencing.com/causes-dispersion-white-light-8425572/

There's one more puzzle piece to consider. The velocity of a wave is a product of its frequency and its wavelength, and the frequency ​f​ of the light does not change as it passes the interface. That means the wavelength must change to preserve the ratio denoted by ​n​. Light with a shorter incident wavelength is refracted at a greater angle than light with a longer wavelength.

Well, there you have it! You can now confidently use a ring light – and you can even create unique photos with some unconventional techniques.

When light passes from a less dense to a more dense medium, as it does when it enters a prism, it splits into its component wavelengths. These recombine when the light exits the prism, and if the two prism faces are parallel, an observer sees white light emerge. Actually, on closer inspection, a thin red line and a thin violet one are visible. They are evidence of slightly different angles of dispersion caused by the slowing down of the light beam in the prism material.

Opticalprism

If light were a true wave, it would need a medium through which to travel, and the universe would have to be filled with a ghostly substance called the ether, as Aristotle believed. The Michelson-Morley experiment proved that no such ether ether exists, however. It turns out that it actually isn't needed to explain light propagation, even though light sometimes behaves as a wave.

Triangularprism

If you have more than one ring light, you can use them together to create just about any two-light setup that you can imagine. And if the ring lights you own offer an adjustable output, managing your key-to-fill ratios should be pretty easy.

Unlike prisms, water droplets are round. Incident sunlight refracts at the air/water interface, and some of it does travel through and emerge from other side, but that isn't the light that produces rainbows. Some of the light reflects inside the water droplet and emerges from the same side of the droplet. That's the light that produces the rainbow.

A ring light is a circular, ring-shaped light designed to be placed directly in front of a subject. You then position your camera in the center of the ring and capture your photos.

Deziel, Chris. What Causes The Dispersion Of White Light? last modified August 30, 2022. https://www.sciencing.com/causes-dispersion-white-light-8425572/

The ​refraction of light​ is the reason why a prism disperses white light forming a spectrum. Refraction occurs because light travels more slowly in a dense medium, such as glass, than it does in air. The formation of a spectrum, of which the rainbow is the visible component, is possible because white light is actually composed of photons with a whole range of wavelengths, and each wavelength refracts at a different angle.

And you’re not limited to putting the light behind your subject. You can place it anywhere in your frame to create cool effects – try putting a ring light above your subject for a halo effect, or placing a ring light at an angle just inside your frame for a curved band of light running through the composition.

The difference between the angle of the incident beam and that of the emergent beam is called the angle of deviation. This angle is essentially zero for all wavelengths when the prism is rectangular. When the faces aren't parallel, each wavelength emerges with its own characteristic angle of deviation, and the bands of the observed rainbow increase in width with increasing distance from the prism.

Generally speaking, ring lights are used as on-axis, even lighting. Because the subject is illuminated from every direction, ring light photography tends to be a bit flat.

Refractionby prism

But how can you use a ring light to create portraits like these? And furthermore, how can you go beyond standard ring light photography to capture photos that stand out from the crowd?

The nature of light was a major controversy in the sciences in the 1600s, and prisms were at the center of the storm. Some scientists believed light was a wave phenomenon, and some thought it was a particle. English physicist and mathematician Sir Isaac Newton was in the former camp – arguably its leader – while Dutch philosopher Christiaan Huygens headed up the opposition.

I love creating compositions that actually include the ring light in the shot; check out this photo, where I framed my subject’s face with the circle of light:

And on-camera ring lights (sometimes called ring flashes), which mount to the front of your lens and provide a narrow band of light.

When the prism is triangular, the angles of incidence as the beam enters and leaves the prism are different, so the angles of refraction are also different. When you hold the prism at the proper angle, you can see the spectrum formed by the individual wavelengths.

These days, ring lights are pretty darn powerful – so you can add them into a studio lighting setup as a gentle, natural-looking fill light.

Opticaldispersion

As long as you own an off-camera ring light, one with a continuous output, you can use the 5 unconventional ring light techniques I share in the next section:

Light is an electromagnetic phenomenon. A changing electric field creates a magnetic field, and vice versa, and the frequency of the changes creates the pulses that form a beam of light. Light travels at a constant speed when traveling through a vacuum, but when traveling through a medium the pulses interact with the atoms in the medium, and the velocity of the wave decreases.

LED ring lights don’t get very hot – so if you own one, test out the temperature, then feel free to let your subject pose with the ring for some unique images.

For portrait photography and videography, off-camera ring lights (as pictured throughout this article) are more versatile; you can position them however you like, plus they offer a wider band of light, which is helpful for larger subjects. Off-camera ring lights also generally offer continuous lighting only, which makes them highly useful for videography and studio photography, but less useful for situations where you need a powerful burst of light in a dark setting (e.g., when photographing a frog at night).

But what if you want to take your ring light photography to the next level? What if you want to create unique, more unusual ring-lit photos?

White light is a combination of light of photons with all possible wavelengths. In the visible spectrum, red light has the longest wavelength, followed by orange, yellow, green, blue, indigo and violet (ROYGBIV). These are the colors of the rainbow, but you'll only see them from a triangular prism.

Despite their circular shape, ring lights work great as normal lights; simply raise the light, angle it toward your subject, and it essentially becomes a small softbox!

The results will vary with ring lights of different sizes, and you do have to worry about the plug and the cables, but it’s still a fun technique. Just make sure not to overuse it (the light has a tendency to illuminate your subject from below, which isn’t the most flattering angle).

So by the time you’re done with this article, you’ll know how to use a ring light like a pro – and you’ll even have a few tricks up your sleeve for the next time you’re after unique images.

Ring-lit portraits don’t feature interesting shadows – for that, you’ll want to look at options such as Rembrandt lighting and loop lighting – but they have a certain flat, vibrant, in-your-face charm. Some photographers love the flat look, and other photographers hate it; it’s really all about personal preference, and it’s certainly possible to use a ring light to great effect.

Note that ring flashes often offer some sort of flash (i.e., strobe) setting, and some of them only work as flashes. If you’re after a powerful burst of light, this is ideal. But be careful before purchasing a ring flash for videography, as you won’t be able to use it unless it offers a continuous setting.

Diffraction is clearly a wave phenomenon, but you can explain refraction as a result of the propagation of particles, as Newton did. To get an accurate idea of what's actually happening, you need to understand what light actually is and how it interacts with the medium through which it travels.

However, with a ring light and a strobe, you can let the ring light act as ambient fill, fire your strobe, and decrease the shutter speed for some stunning effects.

Do you have other ways that you use a ring light? Do you have any tips for ring light photography? Share your thoughts in the comments below!