Low-Voltage Field Reference • Technical term
DORI Distance for Security Cameras: Detect, Observe, Recognize, Identify
DORI is a planning framework that relates pixel density to four surveillance tasks. It is a design checkpoint—not a promise that a camera will identify every subject under every condition.
Direct answer
what is DORI distance for security cameras: the practical answer
DORI is a planning framework that relates pixel density to four surveillance tasks. It is a design checkpoint—not a promise that a camera will identify every subject under every condition.
For a working contractor, the value of this definition is its ability to translate field language into a verifiable design decision. Use the sequence meaning → project consequence → evidence → acceptance. The label alone never proves compatibility, compliance or performance.
What this changes in the design package
DORI Distance for Security Cameras: Detect, Observe, Recognize, Identify should change at least one controlled project record. On a floor plan, identify the physical location or route affected by required surveillance task by zone and target distance and width. On the riser or signal-flow drawing, show how the selected equipment, pathway, power and communications relationships support the intended outcome. In the schedule, preserve the exact data needed to buy, configure, install and test the system.
Plan
Show the device, route, zone or interface in context. Use stable IDs rather than relying on a symbol alone, and flag any assumption that can change quantity or performance.
Riser or schematic
Show origin, destination, intervening equipment, shared infrastructure and interface responsibility. A diagram should expose relationships the floor plan cannot show clearly.
Schedule
Record camera resolution and aspect ratio, lens and mounting geometry, day and night light levels and motion, compression and retention settings where they can be reviewed and revised without redrawing the entire plan.
Proposal
State the verified design basis, named allowances, exclusions, owner/IT/electrical dependencies, testing method and the event that triggers a change order.
Field method
A repeatable definition workflow
Start by deciding what the term must communicate on this project. Then connect the definition to a selected device, a measurable setting, a drawing note and an acceptance result.
- 1. calculate pixels across the target width.
- 2. compare the result with the selected task criterion.
- 3. validate the actual scene at representative light levels.
- 4. record the design basis on the camera schedule.
After the final step, repeat the original operating scenario. A correction is not complete until the system passes the required function, the drawing and schedule match the installed condition, and the handoff record identifies what changed.
Decision and evidence table
| Question | Evidence to collect | Where to record it | Acceptance signal |
|---|---|---|---|
| What controls required surveillance task by zone? | calculate pixels across the target width; use exact model, reading, setting, photo or log evidence. | camera coverage plan, keyed to the same device/cable/door/zone ID. | The reviewed record and field condition agree, with no unresolved assumption hidden as fact. |
| What controls target distance and width? | compare the result with the selected task criterion; use exact model, reading, setting, photo or log evidence. | DORI worksheet by camera, keyed to the same device/cable/door/zone ID. | The reviewed record and field condition agree, with no unresolved assumption hidden as fact. |
| What controls camera resolution and aspect ratio? | validate the actual scene at representative light levels; use exact model, reading, setting, photo or log evidence. | lens and mounting schedule, keyed to the same device/cable/door/zone ID. | The reviewed record and field condition agree, with no unresolved assumption hidden as fact. |
| What controls lens and mounting geometry? | record the design basis on the camera schedule; use exact model, reading, setting, photo or log evidence. | commissioning image set, keyed to the same device/cable/door/zone ID. | The reviewed record and field condition agree, with no unresolved assumption hidden as fact. |
Keep evidence close to the decision it supports. A screenshot without an equipment ID, a cable test without the cable identifier, or a code note without edition and jurisdiction is difficult to audit later.
Technical deep dive
Six controls that make DORI distance defensible
1. required surveillance task by zone
establish required surveillance task by zone before the team commits pixel density to the drawing. Identify who supplied the value, how current it is, which exact device, cable, interface, door, zone or route it controls, and what would invalidate it. If the answer comes from a product sheet, retain the model and revision. If it comes from a field observation, retain the location, timestamp, instrument or screen, and technician. If it comes from a requirement, retain jurisdiction, edition and reviewer.
Use this checkpoint to calculate pixels across the target width. Compare the evidence with the intended video surveillance outcome and the accepted project baseline. A discrepancy should become a named issue with an owner and due date; it should not be buried in a markup. Watch specifically for using horizontal viewing angle alone, because that failure can create a plausible-looking plan while breaking the installation, test or commercial handoff.
Close the checkpoint in the camera coverage plan. Tie it to DORI distance and pixel density with the same stable identifier used on the plan and schedule. The reviewer should be able to see the source, selected value, status, exception and acceptance result without reconstructing the designer’s assumptions from email.
2. target distance and width
measure target distance and width before the team commits camera field of view to the drawing. Identify who supplied the value, how current it is, which exact device, cable, interface, door, zone or route it controls, and what would invalidate it. If the answer comes from a product sheet, retain the model and revision. If it comes from a field observation, retain the location, timestamp, instrument or screen, and technician. If it comes from a requirement, retain jurisdiction, edition and reviewer.
Use this checkpoint to compare the result with the selected task criterion. Compare the evidence with the intended video surveillance outcome and the accepted project baseline. A discrepancy should become a named issue with an owner and due date; it should not be buried in a markup. Watch specifically for treating a laboratory criterion as a performance guarantee, because that failure can create a plausible-looking plan while breaking the installation, test or commercial handoff.
Close the checkpoint in the DORI worksheet by camera. Tie it to DORI distance and camera field of view with the same stable identifier used on the plan and schedule. The reviewer should be able to see the source, selected value, status, exception and acceptance result without reconstructing the designer’s assumptions from email.
3. camera resolution and aspect ratio
trace camera resolution and aspect ratio before the team commits subject identification to the drawing. Identify who supplied the value, how current it is, which exact device, cable, interface, door, zone or route it controls, and what would invalidate it. If the answer comes from a product sheet, retain the model and revision. If it comes from a field observation, retain the location, timestamp, instrument or screen, and technician. If it comes from a requirement, retain jurisdiction, edition and reviewer.
Use this checkpoint to validate the actual scene at representative light levels. Compare the evidence with the intended video surveillance outcome and the accepted project baseline. A discrepancy should become a named issue with an owner and due date; it should not be buried in a markup. Watch specifically for ignoring nighttime shutter speed and motion, because that failure can create a plausible-looking plan while breaking the installation, test or commercial handoff.
Close the checkpoint in the lens and mounting schedule. Tie it to DORI distance and subject identification with the same stable identifier used on the plan and schedule. The reviewer should be able to see the source, selected value, status, exception and acceptance result without reconstructing the designer’s assumptions from email.
4. lens and mounting geometry
reconcile lens and mounting geometry before the team commits lens selection to the drawing. Identify who supplied the value, how current it is, which exact device, cable, interface, door, zone or route it controls, and what would invalidate it. If the answer comes from a product sheet, retain the model and revision. If it comes from a field observation, retain the location, timestamp, instrument or screen, and technician. If it comes from a requirement, retain jurisdiction, edition and reviewer.
Use this checkpoint to record the design basis on the camera schedule. Compare the evidence with the intended video surveillance outcome and the accepted project baseline. A discrepancy should become a named issue with an owner and due date; it should not be buried in a markup. Watch specifically for changing resolution or stream settings after acceptance, because that failure can create a plausible-looking plan while breaking the installation, test or commercial handoff.
Close the checkpoint in the commissioning image set. Tie it to DORI distance and lens selection with the same stable identifier used on the plan and schedule. The reviewer should be able to see the source, selected value, status, exception and acceptance result without reconstructing the designer’s assumptions from email.
5. day and night light levels
challenge day and night light levels before the team commits scene lighting to the drawing. Identify who supplied the value, how current it is, which exact device, cable, interface, door, zone or route it controls, and what would invalidate it. If the answer comes from a product sheet, retain the model and revision. If it comes from a field observation, retain the location, timestamp, instrument or screen, and technician. If it comes from a requirement, retain jurisdiction, edition and reviewer.
Use this checkpoint to calculate pixels across the target width. Compare the evidence with the intended video surveillance outcome and the accepted project baseline. A discrepancy should become a named issue with an owner and due date; it should not be buried in a markup. Watch specifically for using horizontal viewing angle alone, because that failure can create a plausible-looking plan while breaking the installation, test or commercial handoff.
Close the checkpoint in the camera coverage plan. Tie it to DORI distance and scene lighting with the same stable identifier used on the plan and schedule. The reviewer should be able to see the source, selected value, status, exception and acceptance result without reconstructing the designer’s assumptions from email.
6. motion, compression and retention settings
preserve motion, compression and retention settings before the team commits DORI distance to the drawing. Identify who supplied the value, how current it is, which exact device, cable, interface, door, zone or route it controls, and what would invalidate it. If the answer comes from a product sheet, retain the model and revision. If it comes from a field observation, retain the location, timestamp, instrument or screen, and technician. If it comes from a requirement, retain jurisdiction, edition and reviewer.
Use this checkpoint to compare the result with the selected task criterion. Compare the evidence with the intended video surveillance outcome and the accepted project baseline. A discrepancy should become a named issue with an owner and due date; it should not be buried in a markup. Watch specifically for treating a laboratory criterion as a performance guarantee, because that failure can create a plausible-looking plan while breaking the installation, test or commercial handoff.
Close the checkpoint in the DORI worksheet by camera. Tie it to DORI distance and DORI distance with the same stable identifier used on the plan and schedule. The reviewer should be able to see the source, selected value, status, exception and acceptance result without reconstructing the designer’s assumptions from email.
Field-capture worksheet
Before leaving the site, collect enough evidence that another qualified person can reconstruct the decision. Start with the site, floor, room and stable asset ID. Record the date, technician and current drawing revision. Photograph the overall context before taking close-ups, and place a readable label or reference in the image when practical.
- Identity
- Exact manufacturer, model, firmware or listing, terminal names, cable ID, panel/port/zone/door address, and the related plan symbol.
- Observed state
- What the user reported, what the technician reproduced, timestamps, LEDs or messages, logs, settings and whether the condition is continuous or intermittent.
- Measured state
- Applicable voltage, current, resistance, optical level, cable result, protocol status, signal format or environmental condition, including the instrument and test boundary.
- Change control
- The one change made, authorization, before/after evidence, temporary workaround, regression checks and any effect on other devices or shared infrastructure.
For this topic, call out required surveillance task by zone, camera resolution and aspect ratio and day and night light levels. Use the vocabulary DORI distance, pixel density, camera field of view consistently so the field note, drawing, schedule and proposal can be found together.
Worked field example
From an uncertain condition to a controlled record
A renovation team receives a report involving DORI distance. The available plan shows a symbol, but it does not identify required surveillance task by zone, target distance and width or camera resolution and aspect ratio. Instead of pricing or repairing from the incomplete symbol, the team opens a single issue record and assigns the affected equipment, cable or location a stable ID.
The technician collects the current settings, model information, photos and measured state. The designer compares that evidence with the selected equipment documentation and the current authoritative sources listed below. The estimator separates verified scope from allowances. The project manager records who owns any external dependency, such as an electrical circuit, network policy, door hardware condition, AHJ decision or owner-furnished device.
The corrected package includes the camera coverage plan, DORI worksheet by camera and lens and mounting schedule. The team then repeats the operating test under the same conditions that produced the original question. That closed loop turns pixel density and camera field of view from search terms into traceable project decisions instead of isolated notes.
Common failure modes—and why they happen
Failure 01
using horizontal viewing angle alone
This shortcut removes context from the decision. Correct it by returning to the project-specific input, documenting the selected basis, and repeating the affected acceptance test.
Failure 02
treating a laboratory criterion as a performance guarantee
This shortcut removes context from the decision. Correct it by returning to the project-specific input, documenting the selected basis, and repeating the affected acceptance test.
Failure 03
ignoring nighttime shutter speed and motion
This shortcut removes context from the decision. Correct it by returning to the project-specific input, documenting the selected basis, and repeating the affected acceptance test.
Failure 04
changing resolution or stream settings after acceptance
This shortcut removes context from the decision. Correct it by returning to the project-specific input, documenting the selected basis, and repeating the affected acceptance test.
When a failure involves regulated life safety, egress, listing, energized work, public-safety radio, or code interpretation, stop at the boundary of your authorization. Escalate to the responsible qualified party and preserve the condition and evidence.
Minimum contractor deliverables
A useful answer survives the handoff from design to estimating, proposal, installation and closeout. At minimum, create the following:
- camera coverage plan.
- DORI worksheet by camera.
- lens and mounting schedule.
- commissioning image set.
Each deliverable should show the project, revision, author, review status and the identity of the system element it controls. If a value is not verified, label it as an assumption, allowance, pending submittal or owner/AHJ decision. Do not let a blank field become an accidental commitment.
How to carry the answer into scope and proposal language
Describe the outcome first: what the customer will receive, where it applies and how it will be tested. Then name the basis used for DORI distance, including the controlling drawing revision and selected equipment data. Include the labor and documentation needed to produce camera coverage plan and DORI worksheet by camera.
Separate dependencies explicitly. Examples include usable owner drawings, accessible ceilings, working branch power, network addressing and policy, compatible owner equipment, door hardware readiness, permits, shutdown windows, AHJ review and access to occupied areas. If one of those facts is unknown, write an allowance or qualification and define how the price changes when the fact is confirmed.
Finish with acceptance: identify who witnesses the test, what evidence is retained and which result constitutes completion. This makes the page commercially useful without turning it into a product pitch.
Commissioning, handoff and future service
Commissioning should prove the designed function, not simply show that equipment turns on. Run the accepted scenario, an expected failure or trouble state, recovery, and any interface that crosses to network, electrical, fire alarm, door hardware, controls or owner systems. Save results against stable IDs and the approved revision.
At handoff, give the owner the camera coverage plan, DORI worksheet by camera, final configuration, approved substitutions, warranties and the contact path for unresolved external responsibilities. Remove default credentials and temporary access where applicable. Explain which changes can invalidate the result—for example a new firmware release, equipment replacement, changed speaker tap, moved camera, added cable, revised AHJ direction or modified switch policy.
Future service begins by comparing the current condition with this accepted baseline. If the record is missing, recreate it before making broad changes. That discipline reduces repeated troubleshooting, protects proposal scope, and lets the next technician distinguish a design issue from a later operational change.
Frequently asked questions
What should I verify first?
Start with required surveillance task by zone and target distance and width. Establish the exact product, project location and current system state before applying a diagram or changing configuration.
Can I use this page as a construction detail?
Use it as an editorial planning and verification aid. Convert it into a project detail only after reconciling the manufacturer instructions, adopted requirements, approved submittals and responsible professional or AHJ direction.
What belongs in the closeout package?
Include camera coverage plan, DORI worksheet by camera, lens and mounting schedule, commissioning image set, plus test evidence, deviations, final settings and the identity of the person or authority that accepted the result.
What should I read next?
Continue with Security Camera WDR Explained: When Wide Dynamic Range Helps, ONVIF Profile S vs Profile T: What Security Designers Should Specify, PoE Security Camera Offline: A Layer-by-Layer Troubleshooting Guide, NVR Shows Camera Connected but No Image: Troubleshooting Flow and the Video Surveillance design software resource.
Authoritative references and how to use them
These links are starting points for current primary-source information. Confirm the current edition, product revision, publication status, jurisdiction and applicability. Accessed for this release on 2026-08-08.
- ONVIF Profiles — use the source to verify terminology, conformance, published requirements or manufacturer-specific behavior; do not substitute this summary for the controlling document.
- Axis network camera documentation — use the source to verify terminology, conformance, published requirements or manufacturer-specific behavior; do not substitute this summary for the controlling document.
- CISA Secure by Design — use the source to verify terminology, conformance, published requirements or manufacturer-specific behavior; do not substitute this summary for the controlling document.