Modelling Lamp Replacement Guide for Studio Flash Heads
By Firstcall Photographic | Published: 2026-10-31
Category: How-to Guides
Match the right replacement modelling lamp to your studio flash head, from E27 bulbs to Interfit Stellar lamps, and avoid the fitting mistakes that break bulbs or waste money.
Quick answer
Match the replacement lamp to your head's fitting and rated wattage before you buy. For most Bowens and Interfit Stellar heads, an E27 250W Halostar-style modelling bulb is the direct swap; for Interfit daylight heads, use the 30W spiral fluorescent lamp instead.
Why the fitting matters more than the wattage
A modelling lamp that physically fits but exceeds the head's rated wattage can overheat the housing or damage the socket. Check the old lamp's base and wattage first, then confirm the head's maximum rating in its manual. If the manual is missing, use the same wattage as the lamp you are removing rather than guessing upward.
Screw-base E27 lamps are common across Bowens and Interfit Stellar heads, but not every E27 lamp is suitable. Halostar-style 250W lamps are specified for many Gemini and older Esprit units, while Interfit daylight heads use a 30W spiral fluorescent lamp with a different colour temperature. The two are not interchangeable.
Colour temperature and the look you are matching
Modelling lamps are there to show you where the flash will fall, not to be the final light source. A tungsten modelling lamp gives a warm preview, while a fluorescent daylight lamp gives a cooler preview closer to daylight-balanced flash. If you mix lamps across heads in one setup, the previews will not match each other, which makes judging shadow ratios harder.
For black-and-white or colour-critical work, keep all heads on the same lamp type so your visual preview stays consistent. This is a workflow choice, not a rule about which lamp is better.
When a cheaper lamp is the wrong economy
A low-cost lamp that is not specified for your head may run hot, fail early, or foul the socket. The Interfit INT 499 is a standard replacement part for Stellar units and EX300 heads, so it is the safe choice when you want the original fit. The Photolux Halostar 64480 covers a long list of Bowens and Interfit Gemini heads, which makes it a practical spare to keep on hand if you run several older units.
Fluorescent lamps are more fragile than halogen. The Interfit Helix 30W is long-life but should not be over-tightened when screwed in, because the glass can break at the base.
How to replace a modelling lamp step by step
- Switch off and unplug the head: Turn the head off at the mains and let the old lamp cool completely before touching it. Halogen and halogen-style lamps stay hot well after the power is off. Never handle a lamp that has been on within the last few minutes.
- Read the old lamp's base and wattage: Note the base type (E27 screw or otherwise) and the wattage printed on the lamp or the head's rating label. Use that as your specification, not a guess. If the markings are worn off, check the head's manual or the manufacturer's lamp list before ordering.
- Match the lamp to the head, not just the socket: Choose a lamp specified for your head model. For Interfit Stellar and EX300 heads, the INT 499 is the standard replacement; for many Bowens and Gemini heads, the Photolux Halostar 64480 E27 250W is listed as compatible. A lamp that screws in but is not listed for your head is not a confirmed fit.
- Fit the lamp without over-tightening: Screw the lamp in by the base, not the glass, until it is snug. Fluorescent spiral lamps such as the Helix 30W are fragile at the base and can break if forced. Stop at finger-tight; the lamp does not need to be torqued down.
- Test the preview before the shoot: Power the head and check that the modelling lamp lights evenly and that the colour preview matches the other heads in your setup. If one head looks warmer or cooler, you have mixed lamp types. Run this check before packing for a shoot, not on location.
Replacement lamps in the catalog
- Interfit INT 499 Modelling Lamp for Stellar: Replacement modelling lamp for Interfit Stellar units and EX300 flash heads. It is the direct-fit option when you want to restore the original lamp in a Stellar or EX300 head.
Interfit INT 499 Modelling Lamp for Stellar - Photolux Halostar 64480 Modelling Lamp - E27 250W: E27 250W Halostar lamp listed for most Bowens and Interfit Stellar Gemini heads, plus older Esprit 125–750W units. One lamp type can cover a mixed shelf of Bowens and Gemini heads, which simplifies spares.
Photolux Halostar 64480 Modelling Lamp - E27 250W - INT034 Helix 240v 30w 6400K E27 T3 Fluorescent: 30W spiral fluorescent lamp for Interfit daylight heads, rated over 8000 hours with a 5000–5500K colour temperature. It is the correct replacement for daylight heads, not a halogen swap, and its long life reduces how often you need to change it.
