Is Lamp Wattage Really the Most Important Factor?

Choosing an LED film light shouldn’t be based on wattage alone. Understanding the difference between power consumption and actual light output is essential if you want to light a film set properly and avoid technical problems.

Below, we explain the difference between watts, lumens and lux — and how to choose the right light for your shoot.

Lamp Power (W) – What Does It Actually Tell You?

Power expressed in watts tells you how much electrical energy a light consumes over time. For example, a 1000 W light — or 1 kW — will consume 1 kilowatt-hour (1 kWh) of electricity during one hour of operation at full power.

Knowing the power consumption of a light helps you:

• choose the right power source — mains power, generator, portable power station or battery,
• check whether you are likely to exceed the maximum load of an electrical circuit,
• estimate energy consumption,
• compare the efficiency of different light sources.

A Real-World Example from a Film Set

Imagine you are shooting in an apartment in Warsaw. You plug in several lights rented for the production and, a few moments later… the circuit breaker trips.

Why?

A 230 V circuit protected by a 16 A breaker can theoretically provide around 3680 W of power. If you connect four 600 W lights and two 1200 W lights to outlets running on the same electrical circuit, their combined power consumption reaches 4800 W.

The result? An overloaded circuit.

That is why it is always worth checking the electrical installation at your shooting location before choosing your lighting package. Whenever possible, distribute the lights across different circuits. This reduces the risk of overloading the installation, causing a power failure and interrupting the shoot.

Wattage is therefore extremely important from a power and safety perspective — but it does not tell you how bright a light actually is.

Light Output – Lumens and Lux

If you want to understand how much light a fixture produces, you need to look at different specifications.

Lumens (lm)

Lumens describe the total amount of visible light emitted by a light source.

You can think of it as the amount of water flowing from a tap: the more lumens, the more total light the fixture produces.

However, this still does not tell you how bright the light will be at a specific point on your set.

Lux (lx)

Lux tells you how much light reaches a specific surface.

1 lux = 1 lumen per 1 m²

In simple terms:

lux = illuminance at a specific point

This is the value that helps determine whether, for example, an actor’s face will receive enough light.

That is why, when comparing film lights, lux measurements are usually far more useful than wattage alone.

What Affects Lux Measurements?

Lux is not a fixed value. It depends on several factors, including:

• distance from the light — the farther away the fixture is, the lower the illuminance,
• light modifiers — a softbox reduces intensity, while a Fresnel or reflector can concentrate the beam,
• beam angle — a narrower beam usually produces higher illuminance in the centre,
• colour temperature — output can vary depending on the selected CCT, for example 5600K versus 3200K.

The Inverse Square Law

There is one simple but extremely important rule in lighting:

If you move a light twice as far away from the subject, the illuminance drops to approximately one quarter.

This is why exposure can decrease dramatically when you move a fixture farther away.

The inverse square law becomes especially important when lighting larger sets, where lights often need to be positioned farther from the subject.

How to Read a Manufacturer’s Specification

Most manufacturers provide photometric measurements in a format similar to this:

65,000 lx @ 1 m (with 45° reflector) @ 5600K

This means that the fixture produces 65,000 lux at a distance of 1 metre, at a colour temperature of 5600K, using a 45° reflector.

Specifications presented this way make it much easier to compare different lights realistically.

Aputure is one of the manufacturers that provides detailed photometric measurements at different distances and with different configurations. Its specification tables make it easier to understand how a fixture will actually perform on set.

Misleading Specifications and Potential Pitfalls

Unfortunately, there are also some concerns about the way certain manufacturers present their photometric data. This is a topic that comes up regularly in discussions about film lighting.

A good example is the SmallRig RC 220B. According to its specification, the fixture has a power consumption of 260 W and can produce up to 84,000 lux at 1 metre with a reflector.

That is an impressive figure — especially when compared with the much more powerful Aputure LS 600X, which has a power rating of 720 W and produces around 64,000 lux at 1 metre with a reflector.

As you may have noticed, SmallRig does not clearly state the reflector beam angle used to achieve this result. In some materials, we found information suggesting that the measurement was taken using the reflector included with the fixture — although in our opinion, the result is difficult to compare directly without more detailed information about the test conditions.

Because users cannot always easily verify manufacturers’ measurements themselves, specifications can sometimes leave room for selective presentation or incomplete context.

That is why it is worth checking not only the headline lux figure, but also the measurement distance, beam angle, colour temperature and modifier used during testing.

A Modern LED Light Example

Modern LED fixtures, such as Aputure’s STORM series, can deliver very high light output while maintaining relatively low power consumption.

For example, the Aputure STORM 80c, with a power consumption of around 100 W, can produce higher illuminance in certain configurations than the Amaran 150c, despite the latter being rated at 150 W.

This difference comes from more advanced LED technology and optical design, both of which can increase lighting efficiency — in other words, generate more usable light for a given amount of electrical power.

The STORM series uses highly efficient modern LED systems that can deliver greater illuminance without requiring a proportional increase in energy consumption.

As a result, these fixtures can be more energy-efficient, place less strain on electrical circuits and offer greater flexibility on set.

This clearly shows why wattage alone is not a reliable indicator of brightness. What matters is the overall efficiency of the light source, its optical system and the modifiers being used.

Summary – Wattage vs Light Output

When choosing a film light, pay attention to two key specifications:

Watts (W) → tell you how much electrical power the fixture consumes → important for power supply and electrical safety

Lux (lx) → tell you how much light actually reaches your subject → essential for exposure and image quality

If you want to choose lighting for your production intelligently, look at the full specification: photometric measurements, measurement distance, beam angle, colour temperature and modifiers.

Only then can you realistically compare different fixtures and choose the right equipment for your shooting conditions.

CamCam Rental – Film Lighting for Hire

Wattage or brightness? Now you know what to look for.

And if you still have any questions, the CamCam Rental team will be happy to help you choose the right lighting for your production. You are also welcome to visit us and test the equipment free of charge.

At CamCam Rental, you will find not only a wide range of LED film lights, but also light modifiers from trusted manufacturers such as Aputure, Nanlite, Godox and Amaran.

Get the lighting right, and your images will look all the better for it.