HMI, LED or Tungsten? What to Hire for Your Shoot

Choosing a light source isn't an aesthetic decision alone — it's a logistics decision, a power decision, and often a schedule decision. Get it right in prep and the day runs smoothly. Get it wrong and you're pulling workarounds on set while the clock runs. Here's a practical breakdown of the three main source types we hire out and how to match them to your shoot.

HMI: High Output, Daylight Balance, High Commitment

HMI (hydrargyrum medium-arc iodide) fixtures are the workhorses of exterior daylight work and large interior day-exterior looks. A 4K or 6K through a big frame of diffusion can fill a room or compete with harsh Sydney sun. Nothing else in the rental inventory matches that punch-for-punch output at 5,600K.

The trade-offs are real though:

• Power draw. A 6K HMI pulls significant current. On location you're usually talking a generator, a proper cable run, and a ballast positioned close enough to keep voltage drop manageable. That's all planned in prep — not worked out on the morning.
• Warm-up and restrike time. HMIs need a warm-up period to reach full colour temperature, and after a lamp extinguish you wait for a restrike. On a tight schedule, that matters.
• Flicker. Shooting at high frame rates or with a rolling shutter? Flicker from older magnetic ballasts is a known issue. We spec electronic ballasts as standard to avoid it, but it's worth confirming this when you book.
• Lamp life and cost. HMI globes are consumables. Budget for lamp hours if you're running big fixtures across a long shoot.

HMI is the right call when you need to match or overpower daylight at scale, light through windows into a large space, or create hard directional sun that LEDs can't replicate without significant compromise.

LED: Flexible, Efficient, Worth Understanding

LED has moved from a novelty to a genuine production tool. Bi-colour LED panels, flexible mats, tube lights and larger fresnels now cover a huge range of applications that used to require tungsten or HMI.

What makes LED practical on set:

• Low power draw. You can run a lot of LED off standard domestic supply or a modest generator. On tight locations — apartments, small retail spaces, vehicles — that's the difference between a workable day and a power headache.
• Variable colour temperature. Dial between 2,800K and 6,500K without cutting gels. Useful for scenes crossing from interior tungsten to daylight, or documentary-style work where you need to adapt quickly.
• Low heat. Relevant for talent comfort on long days, for food shoots, and for enclosed locations where you can't dump heat easily.
• RGBW and full-spectrum options. For colour work — music videos, stylised content, product shoots — full-spectrum LEDs give you options that no other source matches without extensive gelling.

The limitations to plan around:

• Output ceiling. Even large LED fresnels don't match a 6K HMI for raw punch. For daylight-fill on a bright exterior or lighting a wide through glass, you'll still reach for HMI.
• Green spike and spectral quality. Not all LED is equal. Cheaper fixtures can render skin poorly or introduce a colour cast that's a problem in post. We spec fixtures with high CRI and TLCI ratings for this reason — ask us what's going in your package.
• Interference. Some LED drivers create interference with radio mics. Worth flagging to your sound department and testing before the shoot day.

LED is the right call for interiors with limited power, run-and-gun or documentary work, colour-driven shoots, and anywhere you need to build and move light quickly.

Tungsten: Warm, Predictable, Still Useful

Tungsten hasn't disappeared, and there are good reasons to keep it in the toolkit. A tungsten fresnel or open-face gives you a quality of light — a warmth and a hardness at the edges — that some DPs still prefer for certain looks, particularly in drama and portraiture.

Where tungsten still makes sense:

• Practical matching. If the location has visible tungsten globes or filament practicals, matching with tungsten sources keeps colour consistent without fighting it in post.
• Simplicity. No ballast, no driver, no firmware. Plug in, dim with a conventional dimmer, shoot. For small crews working fast, that simplicity has real value.
• Cost. Tungsten fixtures are generally the most affordable hire option. On a production where budget is tight and output demands are modest, that's a legitimate factor.

The trade-offs: significant heat output (a concern for talent, locations and fire safety compliance), high power draw relative to output, and colour temperature shift as you dim. On a drama where you're using dimmers deliberately for mood, that shift can work for you. In a situation where you need a consistent CCT at varying intensities, it works against you.

Mixing Sources: Where It Gets Interesting

Most packages we put together aren't single-source. A typical commercial interior might combine HMI through the windows for day exterior feel, LED panels for fill and negative fill control, and a couple of tungsten or LED practicals to motivate the scene. The key is planning the mix in prep so the colour decisions are intentional, not reactive.

A mixed package also gives you options when the day throws something unexpected — a cloud that kills your exterior, a location that won't allow a generator, a scene that runs long and needs to be reshaped quickly. Versatility in the truck means flexibility on set.

Making the Right Call in Prep

The source-type conversation should happen in your tech scout or earliest prep discussions, not on the morning of the shoot. The questions that drive the decision:

• What does the DP want the light to feel like?
• What's the location's available power?
• Are there high-frame-rate or slow-motion requirements?
• How much time does the schedule allow for setup and moves?
• Are there heat, noise or safety restrictions at the location?

Bring those answers to us and we'll spec a package that matches both the creative intent and the practical reality of the day. Knowing what's in your lighting package — and why — before you call first positions the crew to work efficiently from the first setup to the last.