01
State what the image needs to explain.
An overview answers what is happening across an area. Useful detail answers a more specific question at a defined place and under defined conditions. Mark entrances, routes, handling areas or other authorised zones on a plan. Megapixels alone do not describe usable information at the required distance.
Record scene width, distance, possible mounting height, obstacles and lighting changes. Identify excluded areas and authorised reviewers. Use a sanitised plan and agreed test objects in the commercial brief. Selecting a reference against a framing assumption is not site acceptance.
02
Form helps mounting; it does not define image quality.
Scroll the table horizontally to compare all three columns.
| Form | Project question | Required check |
|---|---|---|
| Bullet | Do a visible direction and the proposed mounting fit the brief? | Size, mounting, actual view and model-specific exposure limits. |
| Fixed dome | Does the installation allow aiming and cleaning access? | Shape alone proves neither impact rating nor outdoor suitability. |
| PTZ | Who controls movement, with which feedback and agreed positions? | A view aimed at B does not simultaneously inspect detail A. |
| Panoramic | Which overview and corrected views need recording? | Pixel distribution, viewing software and actual export capability. |
03
Choose the lens with the scene and sensor.
Fixed focal length
The field cannot be adjusted by changing focal length. Check the model’s documented angle and framing at actual distance. The same millimetre marking does not necessarily give two cameras the same view; sensor size matters too.
Varifocal and motorised adjustment
A focal-length range helps adjust framing. Confirm adjustment, focusing and remote-control functions. Motorised setup adjustment does not automatically turn a fixed camera into a tracking PTZ.
Light and depth
State whether useful objects occupy one distance or a deep area. Check focus under intended lighting. A sharp daytime still does not validate evening motion; preserve this distinction in the test brief.
Replaceable or integrated lens
Do not assume lens replacement is possible. Where supported, check mount, sensor, functions and exact pairing. State what the camera, lens and mounting selection includes and what remains separately supplied.
04
The same stream across two different scene widths.
ILLUSTRATIVE EXAMPLE
Simplified fictional case: 1920 useful horizontal pixels uniformly span a front-facing plane 8 m or 4 m wide. No model, face or regulatory threshold is used.
Describe the overview
Across 8 m, the horizontal calculation is 240 pixels/m. It explains distribution, not whether detail is identifiable. State which fictional object must be visible and where on the plane.
Narrow the view without hiding the trade-off
Across 4 m, the same hypothetical stream gives 480 pixels/m. Coverage narrows: edges of the previous scene may leave the frame. Simultaneous overview and detail may therefore need two separately assessed views.
Validate the recording
Review the actual recording at its chosen resolution and settings with representative motion and light. Viewer zoom cannot recreate missing detail. These figures ignore perspective, distortion, focus and compression; they guarantee no recognition.
This comparison explains a framing trade-off. It calculates neither a lens to buy, identification distance nor site camera count.
05
Prepare comparable evidence for every view.
Same task and conditions
Compare proposals at the same position and task. Record framing, time, light, motion and recording settings. A marketing photo and compressed clip are not equivalent tests. Document conditions not reproduced.
Mounting and excluded areas
Confirm mounting, maintenance access, exposure limits and authorised view. Check intended masks in relevant views. A protection icon or “outdoor” in a title does not replace exact equipment/accessory documentation.
Operation and handover
Identify each view, purpose, accepted settings and reservations. An authorised user checks playback and export. Account/security details do not belong in the shared commercial pack. Name who rechecks framing after mounting or use changes.
06
A view schedule makes the quotation more precise.
For each view, provide the observation task, plan, known distances, light, possible mounting and constraints. Treat the suggested form as a hypothesis, not an unsupported requirement. Inovexia can match the brief to documented references; the integrator validates scene and installation, with WEXON as a named option if requested.
07
Avoid these selection shortcuts.
Do more megapixels always mean more useful detail?
No. Framing, light, motion, focus and recording matter. Compare the actual task and retained stream, not only nominal resolution.
Is a varifocal camera a PTZ?
No. Adjusting a lens view and physically aiming a camera are different functions. Check motion, zoom, focus and controllable modes for the exact model.
Can a 2.8 mm lens be chosen without knowing the scene?
That figure is insufficient. Sensor, documented angle, distance and useful width are needed. A common catalogue value is not a universal entrance recommendation.
Can one PTZ replace every fixed view?
Not when multiple details must be observed simultaneously. Specify what remains necessary during movement or zoom. Presets do not guarantee simultaneous observation.
Can this guide guarantee plate reading?
No. This specific task needs suitable conditions, equipment, settings and testing. The illustrative pixel-density calculation is neither a specialist-camera selection nor a recognition guarantee.
Technical sources
External reading references. These documents explain principles; they do not certify catalogue products or their combination.
- Lenses in surveillanceAxis Communications · Sources consulted on
- Network cameras — Camera form factorsAxis Communications · Sources consulted on
- Quality with a purposeAxis Communications · Sources consulted on