Louis Poulsen PH 1/1 Portable: A New Chapter in the PH Family

The design language behind the PH 1/1 Portable

To understand the PH 1/1 Portable, it helps to understand the design language it belongs to. In 1925, a 31-year-old Danish architect named Poul Henningsen developed a system of three concentric shades, mathematically proportioned to bounce light downward in a soft, even pool while concealing the bulb completely from view. He used a logarithmic spiral as the foundation, calculating the placement of each shade so light would reflect through three layers of mouth-blown opal glass before reaching the eye. The first prototype won gold at the Paris exhibition that year. A century later, the same three-shade math is the foundation of every PH lamp Louis Poulsen produces.

Henningsen was solving a specific problem. The new electric bulb was brighter and more direct than the gas and kerosene light it replaced, and most early lamps left the bulb visible and the light harsh. His three-shade system answered that problem with mathematics. The bulb is never visible. You see only what the bulb is illuminating, and the pool of light beneath the lamp is calibrated to feel as soft and natural as the lamps it replaced.

The PH 1/1 Portable is built to that same standard. The proportions are the same proportions Henningsen calculated in 1925. The opal glass is mouth-blown in three layers, glossy on the outer surface and sandblasted matte on the inner surface, the way it has always been. The optics are the optics. What is new is the format.

The cordless format

The PH 1/1 Portable runs on a rechargeable battery, with charging handled through a USB-C cable. The same cable that charges most modern phones charges the lamp. Battery life runs 5 hours at full brightness, 9 hours at 45%, and stretches to 60 hours at the lowest dim setting. A full charge takes roughly 5 hours.

The four-step dim-to-warm LED shifts colour temperature as the lamp dims, so the same fixture reads as a clear reading light at full output and as something closer to candlelight at the lowest setting. The detail to know is what the opal glass does at that lowest setting: as the LED shifts toward the warmest colour temperature, the three layers of glass amplify the warmth rather than just transmit it, and the surface beneath the lamp picks up a glow that is closer to firelight than to electric light. A memory feature recalls the last setting when the lamp is turned off and on, which means you can leave it dimmed at your preferred evening level and have it return to that setting the next time you reach for it.

One detail worth knowing: the LED, the charger, and the shades themselves are all replaceable. Louis Poulsen has approached the rest of the PH catalogue this way for nearly a hundred years, and the PH 1/1 Portable carries that philosophy forward into the cordless category. A rechargeable battery is, by definition, a consumable component. Designing the lamp so the battery, the LED, and the glass can all be serviced means the PH 1/1 Portable is a piece you live with for decades.

Chrome or brass

The PH 1/1 Portable is offered in two finishes: high-lustre chrome and metallised brass. Both share the same mouth-blown opal glass shades and throw the same downward pool of light. The difference is what the metal does with the light around it.

Chrome is the cooler, more architectural choice. It reflects whatever room it is sitting in, picks up the surrounding palette, and tends to integrate quietly within a modern interior. It is the version we recommend when the goal is to weave the lamp into a contemporary scheme rather than draw the eye directly to it.

Brass is the warmer, more atmospheric choice. The metallised finish is brushed rather than polished, which keeps it from reading as overtly gold. It catches candlelight, sunset light, and warm interior bulbs in a way the chrome cannot. On a covered terrace at the end of summer, the brass becomes the warmest object in the frame.

Where the PH 1/1 Portable belongs

The proportions of the PH 1/1 Portable suit the surfaces where light is most personal: a bedside table beside a stack of books, a console in an entryway, a writing surface, a bookshelf at eye level, a small dining table set for two. The format opens up one configuration in particular that the wired PH catalogue does not. Picture a long dining table in an open-concept condo, with a pendant hung centrally above it. The pendant carries the room. But at the two ends of the table, where the pendant's pool of light begins to thin, a pair of PH 1/1 Portables in matching brass adds a low, intimate second layer at face level, and the dim-to-warm LED matches the warmth of the pendant overhead. It is the kind of layered lighting that designers build into a room and that most homes never get close to, because it usually requires running new wire. The cordless format makes it a thirty-second decision.

The lamp also rewards being moved. A wired pendant stays where you hang it. The PH 1/1 Portable migrates with the way a home is actually used, from a bedside in the morning to a kitchen counter at dinner to a covered terrace after dark, and the same fixture provides the right kind of light for each of those moments.