Videomaker is always looking for talented, qualified writers. If you have a great idea you’d like to share with our readers, send it to editor@videomaker.com.

Fresnelsled

One of the most important things to know about a Fresnel light is how to pronounce it. There are few quicker ways to be labeled a “newb” (newbie, novice or newcomer) on a film set than by mispronouncing the light as FRAZ-nel. It’s pronounced “Fray-NEL,” with a silent “s.” The name for the light, or more accurately, the lens found in the lighting fixture, refers to the French engineer, Augustin-Jean Fresnel. He invented the technology for lighthouses in the early 1800s. His invention was so well received that he was nominated to be the commissioner of lighthouses in France.

For more free tips on setting up your studio production, check out our ultimate guide to setting up a video production studio.

Fair warning: Never touch a Fresnel’s glass lamp. It doesn’t matter if it’s hot or cold. Even when the lamp is cool, your fingers will leave a small amount of oil on the glass. This will heat up when the lamp is in use. This can cause the lamp to explode, and they aren’t cheap to replace. They can also leave a nasty burn if touched when hot. Seventy percent of the energy used by a tungsten light is dispersed as heat, with only 30 percent visible as light. Use gloves when handling any tungsten lights.

First off, Fresnel lights make things look really nice on camera. They can emit light that’s either soft or hard, so they are highly flexible lights. Most directors of photography (DPs) seem to prefer the color of tungsten Fresnel lights to newer LED lights, as well as the control the traditional lights allow. However, while DPs often prefer tungsten Fresnel lights, LED Fresnels draw much less power and stay cooler. LED fresnels are also dimmable and can even switch between daylight and indoor light in color within their single unit.

Fresnel light effect

Many accessories can be added to Fresnels to further control their light. These are traditionally sold separately. However, some may be included with the new LED Fresnels (depending on the make and model).

Fresnel lights can be expensive. Also, learning how to use them takes time. So, it can be a tough investment to justify without prior experience with the lights. They can also be heavy, making them tricky to transport. These lights probably wouldn’t be a good choice for on-the-go productions or productions that need lights that are quick to set up and disassemble. They need some time to cool down before packing up, so fast-paced productions may find Fresnel lights hard to work with.

Fresnel light theatre

Fresnelslights

Immersion Oil:  Clear, finely detailed images are achieved by contrasting the specimen with their medium.  Changing the refractive index of the specimens from their medium attains this contrast.  The refractive index is a measure of the relative velocity at which light passes through a material.  When light rays pass through the two materials (specimen and medium) that have different refractive indices, the rays change direction from a straight path by bending (refracting) at the boundary between the specimen and the medium.  Thus, this increases the image’s contrast between the specimen and the medium.

A four-leaf barn door mounted to the front brackets of the light can control the beam, for example. Round scrims — metal screens mounted in a metal frame — can reduce light intensity. A speed ring with a softbox can help create a soft, wrap-around light. Traditional tungsten Fresnels don’t come with built-in dimmers, but external dimming systems cost about $50. Blackwrap(TM) or CineFoil(TM) — essentially heavy, black aluminum foil — is useful for shaping light. Attaching Gels and diffusion elements using C47s (a.k.a. wooden clothespins) to change the color or intensity of the light.

Fresnel lights have a lot of good points. But like with any tool, knowing its strengths and weaknesses can help you make the smartest choice. Fresnel lights, when used correctly and in the appropriate settings, can lead to truly cinematic, professional video.

Augustin-Jean’s inspiration came from trying to reduce the weight of a large spherical lens. He did this by carving concentric rings — like the rings of a tree — in a flat lens. Each ring bends the light slightly more than the one beneath it. The results in the light rays all projecting as a beam. Outside of lighthouses and movie sets, Fresnel lenses are also used in car headlights and those large, outdoor event lights that shine into the night sky at movie premieres — like the one Commissioner Gordon uses to summon Batman.

Fresnelswarframe

Please take a few minutes to fill out a brief survey about your experience using the Virtual Edge: https://docs.google.com/forms/d/1yGbkF0KM92WBSk-IgS-EkjxkTKTQwhzuXmDsVpwRDoU/viewform

The Virtual Edge by http://www.uwyo.edu/virtual_edge/ is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License

Fresnel light Lighthouse

Encasing all of this is a housing that dissipates the enormous amount of heat the unit produces. There is a knob, usually in the rear of the housing, which is used to move the lamp/reflector team along a track. This allows the beam to be either spotted or flooded. There are usually four brackets on the front of the light — three fixed and one movable. These brackets hold barn doors, speed rings, scrims and other tools. Finally, there is an AC power jack to provide electricity and a standard stand mount and yoke to mount the light to a light stand or ceiling pipe grid. Simple, right? Trust us, they’re even easier to use than we just explained.

Parfocal: the objective lenses are mounted on the microscope so that they can be interchanged without having to appreciably vary the focus.

Film set Fresnel lights are fairly simple tools and are quick to master. They come in various sizes and intensities and serve as a spotlight or a flood light. The apparatus itself is simple. A lamp (i.e., bulb) sits on a movable track behind a Fresnel lens and in front of a spherical reflector. The reflector directs most of the light towards the Fresnel lens, which then corrals the illumination into a beam.

One way to change the refractive index is by staining the specimen.  Another is to use immersion oil.  While we want light to refract differently between the specimen and the medium, we do not want to lose any light rays, as this would decrease the resolution of the image.  By placing immersion oil between the glass slide and the oil immersion lens (100X), the light rays at the highest magnification can be retained.  Immersion oil has the same refractive index as glass so the oil becomes part of the optics of the microscope.  Without the oil the light rays are refracted as they enter the air between the slide and the lens and the objective lens would have to be increased in diameter in order to capture them.  Using oil has the same effect as increasing the objective diameter therefore improving the resolving power of the lens.

Fresnelsfor sale

Fresnel lights can be found in studios around the world because they are both portable and durable. They are incredibly useful for location shooting and deserve a spot in every professional’s setup. Let’s take a closer look at these lights and why they’re so important in video production today.

If you’ve ever taken a film lighting class, you should know about a typical three-point lighting system. Often used for interviews, three or four Fresnels can act as a key light, a fill light, a rim/hair/backlight and the fourth as an optional background light. You’ve most likely seen the results of thousands of these setups in just about any documentary with a sit-down interview or in long-form news television shows, such as “60 Minutes.” But this isn’t all that you can do with a few of these lights. With the ability to up the intensity and direction for use in more artistic situations, you can create a moodier atmosphere.

Resolving power or resolution: the ability to distinguish objects that are close together.  The better the resolving power of the microscope, the closer together two objects can be and still be seen as separate.

If you want to see what Fresnel lights are truly capable of, do an image search for George Hurrell and you’ll see beautiful portraits utilizing Fresnel lights dating back to the early twentieth century. You’ll find these workhorses of the lighting world on sets and on location across the world, making the movies, television and news shows we watch daily.

Fresnelsmeaning

Total magnification: In a compound microscope the total magnification is the product of the objective and ocular lenses (see figure below).  The magnification of the ocular lenses on your scope is 10X.

Partner with us to reach an enthusiastic audience of students, enthusiasts and professional videographers and filmmakers. Click here to contact a sales representative and request a media kit.

Fresnel lights are also great for product shots where you need to light relatively small, immobile props from a distance. As mentioned earlier, many film stages will have a ceiling pipe grid filled with hanging Fresnels, usually controlled from a light board.