Almost every lighting failure in a home ID photo comes from one of three causes: light from above, light from one side, or light from a flash. All three are fixed by the same move.
The setup
Stand facing a window, with the camera between you and it or just to one side. Stand at least a metre from the wall behind you. Turn off the room lights.
That is the whole technique. A window is a large, soft, neutral source at roughly the right height, which is what a studio spends money replicating.
Why overhead light fails
A ceiling light is above the face, so the brow casts a shadow into the eye sockets, the nose casts one onto the upper lip, and the chin casts one onto the neck. Face-checking software reads deep eye-socket shadow as poor lighting, and sometimes as closed eyes.
It also usually leaves the background darker than the face, because the wall behind you is further from the lamp.
Why flash fails
A phone flash is a small, hard source a few centimetres from the lens. It produces specular highlights on the skin, harsh edges on every shadow, red-eye, and - because it is so close to the axis of the lens - a distinct dark outline on the wall behind you wherever the head blocks it.
If you are anywhere near a window in daylight, the window is a better light.
Why side light fails
Light from one side gives one bright cheek and one dark one, and puts a gradient across the background. Both are checked. The fix is to turn and face the source rather than standing side-on to it.
Mixed colour
Daylight is blue-ish; a filament or warm LED lamp is orange. With both on a face, one side is cool and the other warm, and no white balance setting fixes both at once. Turn the lamps off and use one source.
Practical adjustments
- Too dark? Move closer to the window rather than raising the phone's exposure, which adds noise.
- Harsh sunlight? A net curtain or a thin white sheet over the window turns direct sun into a soft source. Overcast daylight is ideal as it is.
- Shadow under the chin? Something white on your lap or a sheet of paper on a table in front of you bounces light back up.
- Still a shadow on the wall? Move further from it. Separation beats every other fix.
What good lighting looks like
Even brightness across both cheeks, eyes clearly visible with no dark sockets, no hard-edged shadow anywhere, a background that is uniform corner to corner, and skin tones that look like your skin.
IDShot measures lighting, shadow and exposure as separate checks, so a photo with even light on the face but a shadow on the wall tells you which of the two to fix.