HMI vs Tungsten vs LED | Key Differences

Lighting is the crucial element in the photography/filmmaking process that induces the tone for a scene. Filmmakers use HMI or tungsten or LED lights, but how do they select the right one for the right need? What are the parameters to choose the right light for a scene? We will go through the underlying principle of each light, and then compare the most important parameters in lighting. Let’s take a look at HMI vs Tungsten vs LED comparison.

Working Principle | HMI vs Tungsten vs LED

For a better understanding, we will start from the oldest one, tungsten, to the latest one, LED. This section will give you a brief grasp of how these lights work internally.

Tungsten Lights

Tungsten bulbs have been around since 1910 s or earlier. Modern tungsten lights used in filmmaking is almost similar to the incandescent lights used at our home. The bulb has a piece of tungsten filament that emits light when a current passes through it. In addition, modern tungsten bulbs also use the halogen cycle to deposit back the tungsten metal. Filmmakers really love the warm color output quality from Tungsten lights.

HMI Lights

HMI stands for hydrargyrum medium-arc iodide. They are the most used high power light sources in the industry. Unlike tungsten filament, HMI uses two electrodes that excite the mercury vapor and metal halides. Therefore, they have incredible electricity to light conversion ratio, almost 4 times that of tungsten lights.

LED Lights

Light Emitting Diodes(LED) is the most recent addition to the lighting products in the movie-making industry. LEDs are semiconductor devices that emit light when electricity passes through it. They are quite flexible to work with and are very energy efficient.

Showdown | HMI vs Tungsten vs LED

Output Power

The development of HMI light was to tackle the disadvantages of conventional tungsten lights. HMI lights produce 4 times as light as tungsten lights with the same power rating. These lights are capable of delivering astonishing brightness. HMIs are mostly used in high-end film studios and comes in different output options up to 18,000 KW.

LEDs on the other hand take the game to a whole new level. These are extremely energy efficient and offer a great price to performance ratio. HMI or tungsten lights are nowhere near LEDs numbers in terms of efficiency. However, LEDs cannot deliver high-intensity output as HMI. And therefore, HMI lights are used for outdoor shooting to compensate for the effects of the sun and apply artificial lighting.

Power Consumption

HMI and tungsten lights are the least efficient ones. The immense power delivery takes a toll on their power consumption. If you are thinking about a small scale studio or indoor shooting, be careful before connecting HMIs or tungsten lamps to your power socket. Find out the power rating of the circuit and make sure that it matches with the lights.

LEDs are efficient than the other two and hence consume less power. LEDs have the least heat generation over continuous usage compared to HMI and tungsten lights. The high power consumption of HMIs and especially tungsten lights generate very high heat. The talent cannot be close to the lights as it may burn them. A safety rating with minimum separation between light and subject is provided with every light source. Make sure that you are aware and stay safe while shooting.

Color Temperature | HMI vs Tungsten vs LED

HMI and tungsten lamps have a fixed color temperature. In contrast, LED comes in either fixed or variable color temperatures. This in turn allows the filmmaker to tune the color of the output and select a tone that aids the scene. LED lights are widely used in the movie industry due to this flexibility, and its power delivery.

Now we’re seeing LED panels like ARRI Skypanel and LED fresnel lights in the market that support the entire RGB color space.

The color temperature of tungsten lights is around 3200K whereas the color temperature of HMI lights is around 6000K (nearly the temperature of sunlight at noon).

Dimming

Dimming of the light from 100% to 0% is offered by tungsten and LED lights, whereas the HMI supports dimming only up to 50%. This feature enables the filmmaker to control the brightness or the output power of the lamp. Otherwise, they would have to change the lamp for every other brightness for each scene.

Now that we have covered some key aspects of a light source, it is safe to say that there is no one light that suits every occasion. Technology is progressing rapidly and it seems that LEDs will completely take over Tungsten and HMI lights with time. Before choosing your light, you have to weigh in your requirements: outdoor or indoor, small scale production or a grandeur one, time of the shooting, and everything else.

Commonly used HMI, Tungsten, & LED lights in the Film industry: