Quick answer: A hazy night image can come from IR reflections, a dirty or damaged cover, condensation, focus or exposure. Start with non-invasive checks and the exact model’s instructions. Where the design uses an IR shield, keep it fitted as specified; do not modify it or the seal. A daytime night-mode check is preliminary. Confirm the final recorded moving-target image after dark before closing the job.
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What causes IR reflection in a dome, and what does it look like?
IR from the camera can reflect from the dome or a nearby surface into the lens, producing haze, halos or bright patches. Similar symptoms can also come from dirt, condensation, focus or exposure. Compare day/night recordings and static versus moving detail before deciding on the cause; a clear daytime image alone does not identify the fault.
| Observed symptom | Possible causes | Next controlled check |
|---|---|---|
| Gray haze or halo with IR active | Internal reflection, contamination or an incorrectly fitted model-specific cover/shield | Inspect externally first; follow the exact manual before opening or servicing |
| Bright patch near an edge | Nearby reflective surface, cover edge or unsuitable aim | Compare the actual IR field and supported adjustment range; no universal one-metre clearance |
| Spots, glow or visible debris | Dirt, web, droplets or surface damage | Use only the approved cleaning method; assess damage and replacement through support |
| Static image sharp, moving subject blurred | Exposure/lighting or motion, not necessarily focus | Test moving recorded targets at the required lighting and settings |
| Persistent softness or internal moisture | Focus, condensation, cover or sealing fault | Use the model’s focus/service process; do not improvise drying or resealing |
Wider night-image faults, including external fog, insects drawn to the IR and spider webs, are covered in night image problems: IR glare, foggy domes, insects and spider webs. This article focuses on installation and acceptance checks at the camera.
Follow the model’s IR shield and cover design
Some IR dome designs use a shield or ring to separate the lens from IR illumination. Its shape, required contact and permitted adjustment are model-specific. Follow the exact installation guide rather than copying another camera’s ring arrangement. If a part is absent or damaged, stop and ask for the approved replacement/service procedure.
- Check the correct cover, shield and gasket against the exact model instructions; do not remove or reshape an optical separator.
- Keep adjustment within the documented mechanical and optical limits. A ring’s apparent contact is not a substitute for the specified range.
- Follow the specified cover seating, fasteners and torque. Remove protective film only as instructed and avoid pinching or contaminating seals.
The cover is an optical and protective component. CS-I8KS SD-2.8mm lists IK10 and IP67 for the specified product; that does not prove those ratings remain intact after damage, disassembly or an improvised repair. A scratch may affect the image, and damage needs the approved assessment/replacement process. Treat the surface carefully and do not claim a scratched cover is still rated.
Angle limits: how far can you tilt before the bubble fights back?
Check the exact dome’s permitted adjustment range, cover clearance and recorded view. Near-horizontal aims can expose reflections, housing edges or distortion on some designs, but there is no universal downward-only rule. If the required view cannot be achieved within the instructions, choose an approved alternative mount, position or camera rather than forcing the mechanism. Use the IP camera user manual for the exact revision before changing aim or mounting parts.
- Measure the required target positions and recorded detail; use mounting-height guidance as planning, not a fixed angle prescription.
- Check the actual model and compatible bracket/pendant instructions before changing the mounting arrangement.
- Assess nearby walls, soffits, signs and other reflective surfaces in the actual view. A junction box or one-metre setback does not automatically cure glare.
- Keep the final aim within documented limits, secure it as instructed and test the finished cover and view by day and night.
A turret or bullet may suit a position where its actual optical layout, adjustment range and protection meet the task. Housing names alone do not prove separate IR windows, freedom from reflection or better image quality. Compare the exact designs, compatible mounts and recorded result; use bullet vs dome vs turret for the wider selection questions.
Focus: why a dome goes soft after dark
CS-I8KS SD-2.8mm and CS-I5KS SD-2.8mm list fixed 2.8mm lenses; CS-I8MS SD-2.7-13.5mm lists an adjustable focal-length range, 50m maximum IR and 15m white light. The range alone does not prove motorized control or one focusing procedure. Check contamination, moisture, cover seating and exposure as well as focus, then follow the exact manual with the final cover fitted. Assess the actual recorded full-resolution output and moving targets; a higher megapixel count neither diagnoses nor guarantees a visible focus fault.
Night test before leaving the site
If the model supports a manual day/night mode, use it as an early check under controlled conditions. Verify IR and white-light controls separately: selecting a monochrome/night setting does not universally turn IR on. Use a supported camera/NVR/client control path and retain the intended configuration. A daytime pre-check cannot reproduce the actual night scene or prove a callback reduction. The Axis image-quality troubleshooting guide explains general reflection and motion-blur checks; its cleaning products and interface steps are not CASE service instructions.
- Record the existing approved settings and identify the supported day/night and illumination controls.
- Check the image externally for contamination, reflective surfaces, exposure and movement before deciding to open the housing.
- If service is necessary, use the exact shield, cover and seal instructions; do not improvise a ring, gasket, drying method or desiccant.
- Adjust focus only by the model’s supported procedure and confirm final framing with the cover in its installed state.
- Test available white light only where supported and permitted; check the actual scene for flare.
- Restore the intended operating mode and keep recorded after-dark moving-target evidence before final acceptance.
On a multi-dome job, test the first unit before fitting the rest. The commissioning record belongs with the handover file in CCTV installation documentation: a labeling standard.
Cleaning: how to keep the bubble optical
Inspect and clean on a site-appropriate interval using the exact cover material’s approved method and products. Do not infer that a generic soap, spray, solvent or cloth is suitable for every optical coating. Avoid dry abrasive wiping; refer scratches, internal moisture or a damaged seal to the approved service process rather than heating, adding desiccant or opening/resealing by guesswork. Record the condition and the work performed. Confirm the written cover, cleaning and warranty terms for the exact supplied model/revision. Contact the supplying installer/dealer for assessment; cleaning or damage is not automatically covered.
What to tell your customer
We will check the finished camera and keep the relevant night recordings, including moving targets. If the image becomes hazy, contact us before opening or cleaning the cover with an unapproved product. We will distinguish contamination, reflection, exposure, focus and possible moisture, then follow the actual model’s service instructions. Warranty assessment follows the written terms for the supplied equipment.
FAQ
Why is a dome camera foggy or milky only at night?
IR reflection is one possibility, especially when haze changes with illumination, but dirt, moisture, focus and exposure can look similar. Compare actual recordings, inspect externally and follow the model instructions for any cover/shield checks. Do not diagnose from the symptom alone or assume a fixed clearance solves it.
What does the foam light shield on a dome camera do, and can I leave it off?
Where that model uses one, it helps separate the lens from unwanted IR paths. Keep the correct part installed exactly as the model guide specifies. Do not remove, reshape or improvise it, and do not use another manufacturer’s ring/contact instructions as a CASE service procedure.
How far can I tilt a dome camera toward horizontal?
Use the exact model’s documented range and compatible mounting instructions, then test the final cover, aim and recorded target view. There is no universal safe tilt angle or ring-contact test for all domes. Where the position cannot meet the task within those limits, assess a different approved mount, location or model. Use the mounting-height guide for the related recorded-target and access planning.
How do I test a dome’s night image during the day?
Where supported, use the documented day/night and illumination controls separately to make a preliminary check. Confirm the actual image and available control path rather than assuming night mode activates IR or that CASE Connect exposes every setting. Restore the intended configuration and complete a real after-dark recorded test, including moving targets and the site lighting.
References
- Anabon: exact-model manuals, firmware and installation documents
- Axis: general image-quality and IR-reflection troubleshooting; not CASE service instructions
