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Faces black against a bright doorway

very common

“Everybody walking in is a silhouette. And certain times of year the sun comes straight down the lens for twenty minutes and the whole picture's gone.”

Likely causes

  • Camera aimed at glazing or an open doorway: a siting fault, not a settings fault

    most common

    The bright area is the background behind every subject. Exposure meters the glass, the face goes to silhouette, and no WDR setting fully recovers a subject orders of magnitude darker than what is behind it.

  • Direct sun into the lens at a particular time of year

    common

    Unusable for twenty minutes at the same clock time, for a few weeks, then fine again. Sun elevation follows the season, so the complaint appears and disappears on a calendar rather than a daily cycle, which is exactly why nobody can reproduce it on demand. Ask what date it happened, not just what time.

  • WDR off, set too low, or fighting a backlight-compensation setting

    less common

    Highlights clipped and shadows crushed at the same time, with WDR reported as on. Check whether it is true multi-exposure WDR or a tone-curve backlight compensation: different tools competing for the same marketing space.

  • Lens flare and internal reflection off the bubble or sunshield

    Milky veiling or coloured streaks with a bright source just outside the field of view. Shade the lens with your hand from outside frame: if it clears, it is flare, not exposure.

  • WDR artefacts mistaken for a fault

    Ghosting or a halo around moving subjects in the blended region, and motion looks strange. Multi-exposure blending has a cost and at high strength it shows.

  • Nothing to expose for: the subject is genuinely unlit

    The interior side of the doorway has no light of its own. The camera is not failing; there is no light on the face, and the fix is lighting or geometry.

  • Identification expected where the scene cannot deliver it

    The requirement was identification and the design put the camera facing the entrance. Compare pixel density and lighting against the stated requirement before anyone argues about settings.

What to bring

  • Camera web UI with manual exposure and WDR control
  • Sunshield and baffle hardware
  • Lens cloth
  • Sun path information for the site: the date matters as much as the time
  • Ladder or lift
  • Sample captures and job file

Safety

Reaiming, fitting a sunshield and adding a baffle are all work at the camera. Set the platform under it and reposition rather than reaching, and be aware that at an entrance you are usually working over a traffic route: barrier it off rather than trusting people to walk around you.

Steps

  1. Look at what the camera is metering

    If the bright area is behind your subject in every single frame, this is geometry. Say so early: an afternoon of settings work will not change it.

    If that doesn’t do it

    Bright area is not behind the subject: go to WDR and exposure.

  2. Reaim or reposition so the bright source is out of frame

    Shoot across the doorway rather than facing it, or move to catch faces as they turn inside. A camera aimed across the traffic flow with the glass out of frame beats the best WDR setting on a camera aimed at the glass. Free, if the mount allows it.

    If that doesn’t do it

    Mount cannot be moved: work the exposure.

  3. Enable or raise true WDR, then look at what it costs

    Confirm it is multi-exposure WDR rather than a tone curve, set it to what the scene needs, then check moving subjects for ghosting and back it off until motion is acceptable. Capability, strength scale and naming all vary by model and generation. Check the data sheet for that part number rather than assuming parity across the fleet.

    If that doesn’t do it

    WDR at its limit and faces still black: meter for the face.

  4. Meter for the face, not the frame

    Spot or region-weighted metering on the subject area, with the highlight allowed to clip. A blown-out doorway and a usable face is the right trade at an entrance, and it is worth saying that out loud to the customer so it is not logged as a defect.

    If that doesn’t do it

    Face exposed and the image is still unusable at certain times: kill the flare.

  5. Shade the lens and cut the flare

    Sunshield fitted and correctly positioned, bubble clean and unscratched, external baffle or a recess where a source sits just outside frame. Internal reflection off a dirty or crazed bubble is a large part of what gets called glare.

    If that doesn’t do it

    Flare controlled and the scene still fails: fix the scene.

  6. Fix the scene rather than the camera where that is the honest answer

    Light the interior side of the doorway, add a blind or film to the glazing, or move the camera. Backlight and glare are lighting and siting problems; a camera setting can only trade one loss for another.

    If that doesn’t do it

    Customer will not change the scene: document and quantify.

  7. Check the result against the stated requirement, in the worst light, on the worst date

    Capture samples at the bad time and note the date. Where the scene cannot meet the identification requirement, put that in writing with the samples attached and price the fix. This is the symptom that becomes a dispute if you leave it undocumented.

References

  • IEC 62676-4

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