Movie Lighting: The Fly Swatter Moonbounce

Recreating the soft, ethereal glow of moonlight in film production is a challenge that has tested cinematographers for decades. You can’t simply point a powerful light at your scene and call it a night. Natural moonlight is diffused, bounces off surfaces, and fills shadows in a way that a single, harsh light source can never replicate. That’s where a powerful tool — often overlooked by aspiring filmmakers — comes into play: the fly swatter. 

This article will give you a taste of the techniques used by Hollywood professionals to craft believable and beautiful night exteriors, focusing on how a properly rigged fly swatter can transform your set.

MOONLIGHT AMBIENCE TECHNIQUES: IT’S ALL ABOUT THE BOUNCE

Cinematographer Shane Hurlbut, ASC, understands that emulating moonlight isn’t about raw power; it’s about the quality of light. Think about how real moonlight works. It’s not a direct beam; it’s reflected and scattered light. It bounces off buildings, the ground, and even the atmosphere itself. This creates a soft, ambient glow that fills in shadows and wraps around objects.

To achieve this on set, we use a technique called “fly swatting.” A fly swatter, in film terms, is a large frame (often 20×20 feet!) covered with a reflective or diffusive material. This frame is then rigged to a Condor boom lift, placing it high above the set, mimicking the position of the moon.

There are two primary approaches…

1. MOON BOUNCE

We can bounce powerful lights off the fly swatter’s surface. This creates a large, soft source, spreading the light over a wide area. 

The choice of bounce material is crucial. A bleached muslin fabric provides a gentle, diffused reflection, perfect for that classic moonlight look. An “ultra bounce” material, on the other hand, creates a harder, more specular reflection. This is useful for creating highlights or a slightly more stylized feel.

2. MOON BOX

Alternatively, we can place lighting units within the frame, creating a large, diffused light source directly. Grips accomplish this technique with specialized lighting panels.

In this article (and the full course), we’ll focus on the bounce technique, specifically using a 20×20 fly swatter with bleached muslin.

BUILDING THE FLY SWATTER SETUP: RIGGING FOR SUCCESS

The fly swatter isn’t just about the fabric; it’s about the rigging. Local 80 Key Grip Brendan Riel emphasizes that a safe and effective fly swatter setup requires careful construction and a thorough understanding of weight distribution and stability.

The core of the setup is a 20×20 foot frame, typically made of speed rail. This frame is then attached to a Condor boom lift — a powerful piece of equipment that allows us to position the fly swatter high above the set. But we can’t just hang the frame directly from the Condor basket. We need a support structure.

Inside the Condor basket, we build a “goal post” using speed rail and cheeseboros (heavy-duty clamps). This goal post provides the primary attachment points for the frame. Then, a tri-truss — a triangular structure built from speed rail and specialized connectors — extends from the goal post to support the 20×20 frame itself. Finally, kickers (additional lengths of speed rail) are added to provide extra stability and prevent the frame from swaying or twisting in the wind.

CALCULATING WEIGHT CAPACITY & SAFETY: IT’S MORE THAN JUST ADDING NUMBERS

Safety is the paramount concern when working with aerial lifts and large, heavy rigs. It’s not enough to simply add up the weight of the frame, fabric, and rigging hardware. We need to understand the combined center of gravity and how it affects the Condor’s weight capacity.

Direct weight is considered anything positioned behind the Condor’s control panel (towards the arm). Likewise, adjusted weight is anything in front of the panel (towards the outer edge of the basket). The adjusted weight has a much greater impact on the lift’s stability.

To calculate the adjusted weight, we consult the manufacturer’s manual (in this case, JLG’s supplemental manual). This manual provides charts that help us determine the safe operating limits based on the adjusted weight and the new center of gravity. Failing to perform these calculations accurately could lead to catastrophic equipment failure and serious injury.

FINAL PREPARATIONS & SAFETY MEASURES: READY TO FLY 

Once the frame is built, the tri-truss attached, and the kickers in place, it’s time for final adjustments. The frame must be perfectly level to ensure even light reflection. Achieve this by using a combination of tag lines (ropes) and making careful adjustments to the speed rail kickers.

Then, attach the bleached muslin bounce material to the frame. Cleanliness is critical here — any smudges or dirt on the white fabric will be visible in the reflected light. After that, secure the fabric at the corners first, then the center points, ensuring even tension and a smooth, wrinkle-free surface.

Before raising the fly swatter, double-check all connections and make sure to carefully monitor the wind speed. For a 20×20 fly swatter, the recommended maximum wind speed is typically between 5 and 11 mph, according to JLG guidelines.

THE BOTTOM LINE: MASTERING THE ART OF ARTIFICIAL MOONLIGHT

The fly swatter, when properly rigged and deployed, is an incredibly powerful tool for creating beautiful, realistic moonlight on film. It allows cinematographers to control the quality, direction, and intensity of the light, shaping the scene and creating a specific mood. But it’s not a simple setup. It requires a deep understanding of rigging principles, weight calculations, and safety procedures.

Want to see the Fly Swatter in action and learn the complete process from start to finish?

GET THE NIGHT CINEMATOGRAPHY MASTERCLASS

This article only scratches the surface of what you’ll learn in the full Night Cinematography Masterclass. You’ll see Shane Hurlbut, ASC, and Brendan Riel build and deploy the 20×20 fly swatter, step-by-step, with detailed explanations and close-up shots of every connection. 

You’ll learn:

• Detailed weight calculations and safety procedures.
• How to build the goal post and tri-truss.
• The art of triangulation for maximum stability.
• How to level the frame and attach the bounce material perfectly.
• And much, much more!

Don’t just read about it — see it! Unlock the secrets of professional night cinematography and elevate your filmmaking to the next level. Click here to get the Night Cinematography Masterclass today!