Shooting a walkthrough in low light for a 3D tour

A photo in low light looks fine because the phone's computational pipeline stacks several frames and smooths the noise away. A video cannot stack; it has one frame per tick and has to move on. So it opens the shutter longer and pushes ISO. The longer shutter smears anything that moves, including the camera, and the noise reduction that follows flattens fine detail into plastic.

Structure-from-motion needs fine detail. It matches small, distinctive patches between frames: the grain on a floorboard, the edge of a tile, a scuff on the wall. Noise reduction removes exactly those. A dim room does not just look darker in the tour; it reconstructs worse, because the solver had less to hold on to.

Light the room as if you were selling it, then add more.

• Every ceiling light and lamp on. Including the awkward ones.
• Replace any dead bulbs. One dark corner is a hole in the tour.
• Open interior doors so light spills between rooms and the transitions are gentler.
• Set blinds to the same height in every room. A consistent exterior level matters more than a bright one.
• If there is a bright window and a dark room, film with your back to the window where you can, or wait for an overcast hour so the contrast drops.
• Basements and windowless bathrooms: bring a cheap LED panel or a floor lamp from another room. Bounce it off the ceiling rather than pointing it at the wall.

Only a few, and they are small next to the light itself.

Lock exposure. On iPhone, tap and hold on a mid-tone surface until AE/AF LOCK appears. On most Android phones, tap then find the lock icon. This stops the brightness pumping every time a window enters the frame. Set it in the dimmest room you care about and leave it.

Frame rate: 30, not 60. At 60 fps the maximum shutter time is halved, which forces more ISO. 30 fps gives the sensor twice the light per frame.

Resolution: 1080p. Smaller pixels at 4K gather less light each. 1080p is cleaner in the dark and keeps you well under the 500 MB limit.

Turn off cinematic and portrait modes. Synthetic background blur is poison for reconstruction. Night mode is for stills only and does not apply to video on most phones.

Slower, and in straight lines. Motion blur is the product of shutter time and camera speed. You cannot shorten the shutter in the dark, so you reduce speed. Walk at half pace. Do not pan at all if you can help it; instead, stop, turn slowly over three or four seconds, then walk again.

Hold the phone with both hands, elbows against your ribs. A gimbal helps but is not required. Avoid stairs in the dark if you can light them; if not, pause at the top and bottom so there are sharp frames at both ends.

If the room has windows, almost always. Flat daylight on an overcast day is the best light a reconstruction can get: even, bright, no hard shadows that shift as you move. A night shoot with every lamp on will reconstruct, but the result carries the warm, uneven look of the lamps and the texture loss of high ISO.

For a listing, that may be fine. For a short-term rental where the tour is the first impression, it is worth the reshoot. A failed reconstruction on VOLUME is never charged, so the cost of trying the dim version first is only the time.