Strokkur, the geyser that actually goes off

The Geysir field at Haukadalur has one performer: Strokkur, which erupts every few minutes, unlike its famous neighbour Geysir, which mostly does not. Before each eruption the water in the vent domes up into a turquoise blister, and then a white column punches twenty to thirty metres into the air and collapses in steam. Around it the geothermal field steams from a hundred smaller vents and the ground is stained orange and grey.

The photographs come in two kinds. The literal one is the column itself, best shot with the couple in the foreground and the eruption behind: you get several attempts an hour, so it is a matter of pre-framing, waiting for the dome and firing. The better one is often the steam — figures walking through drifting geothermal fog on the boardwalk, everything grey and soft, with colour only in the pools. Cold days make far more steam than warm ones, which is why winter here photographs better than summer.

Light and timing: the field faces open sky, so overcast light is kind and direct sun is not. Early morning before the coaches and late evening after them are the quiet windows; in June that means the light is still workable at eleven at night, and in December the whole show happens in a four-hour blue-grey day, which suits it.

Safety at Geysir is not a formality. The water in these vents is near boiling and the ground beside the paths can be a thin crust — stay on the marked paths and boardwalks, keep children in hand, and keep well back from every pool, not just the roped ones. Downwind of Strokkur you will be rained on with hot water; check which way the wind is blowing before choosing a stance, and move rather than tough it out.