Knowledge · Cameras
How an area scan camera captures a full 2D frame in one exposure for discrete field-of-view inspection in Computer Vision.
A technical reference on sensor geometry, resolution and triggering for engineers and integrators.
You understand how an area scan sensor captures a full frame. Decide whether discrete FOV geometry fits your line, then continue to full camera selection.
An area scan camera is an industrial camera that captures a full two-dimensional image in a single exposure. The sensor is a rectangular grid of pixels, rows and columns, so one trigger produces one complete frame: height × width, just like a photograph, but built for machines that run all day.
That simple idea is why area scan dominates most Computer Vision stations. If your part fits in a field of view, sits still (or moves slowly enough) during exposure, and the defect or feature is visible in a 2D image, an area scan camera is usually the right starting point. You mount a lens, light the scene, trigger on a PLC pulse or encoder, and send frames to a PC, smart system, or vision controller.
In product catalogues you will also see labels such as matrix camera, 2D industrial camera, or simply Computer Vision camera. In Sedeco’s taxonomy those sit under Cameras, with area scan as the default family for discrete-part inspection.
In one sentence
An area scan camera freezes a rectangular scene into one digital image so software can measure, classify, read, or decide pass/fail.
Think of the optical path as four linked decisions: scene → lens → sensor → interface.
A part arrives in the station. A sensor, PLC, robot, or encoder tells the camera “now.” During the exposure time, photons from the illuminated scene hit the sensor. If the part moves too far during that window, the image blurs, which is why lighting, shutter type, and exposure time matter as much as megapixels.
The lens maps object size and working distance onto the sensor. Focal length, aperture, distortion, and resolution class decide whether a 0.2 mm scratch is even resolvable. Camera choice without lens choice is incomplete, see our lenses overview when you size field of view.
An area scan sensor is a 2D array. Each pixel integrates light for the exposure. Mono sensors measure intensity; color sensors typically use a Bayer filter and interpolate RGB. Pixel size (often a few micrometers) and sensor format (for example 1/2.9", 1/1.8", or larger) affect sensitivity, depth of field via optics, and how much of the optical circle you use.
After readout, the camera streams the frame over GigE Vision, USB3 Vision, Camera Link, CoaXPress, or another industrial interface. GenICam-style control lets software set exposure, gain, trigger mode, and ROI without proprietary lock-in on most modern cameras.
| Stage | What happens | What this means |
|---|---|---|
| Trigger | External or free-run start of exposure | Match PLC / encoder timing |
| Exposure | Sensor integrates light | Motion blur vs light budget |
| Readout | Pixels become a digital frame | Frame rate & ROI limits |
| Transfer | Image leaves the camera | Cable length, bandwidth, PC load |
Teams often ask for “an industrial camera” when they actually need a family decision. Use this comparison as a filter before you open a datasheet.
| Family | Captures | Best when | Watch-outs |
|---|---|---|---|
| Area scan | Full 2D frame per trigger | Discrete parts in a FOV; most QC stations | Fast continuous webs may need line scan |
| Line scan | One line at a time, built into a 2D image | High-speed conveyors, film, metal strip, print | Needs precise motion sync & lighting |
| Smart camera | Image + onboard processing | Standard ID, OCR, presence, simple QC | Less flexible than a full PC stack |
| 3D camera | Shape, height, volume, pose | Bin picking, volume, height defects | Overkill if contrast in 2D is enough |
Area scan vs line scan: if the product is a discrete object that stops or moves slowly in a window, area scan is simpler. If material streams continuously and you need microscopic defects along meters of product, line scan is usually the tool. Many factories use both, area scan on assembly stations, line scan on webs.
Area scan vs smart camera: a “plain” area scan camera delivers images to a PC or controller. A smart camera embeds tools on the device. Architecture comes first, see also our smart camera guide and smart camera vs PC-based vision, then you pick the sensor family.
Area scan vs 3D: area scan answers “what does it look like in 2D?” 3D answers “what is its shape and pose?” Surface print defects often need area scan; grasping randomly piled parts often needs 3D.
If you are buying Computer Vision for the first time, these patterns cover most successful area-scan projects:
Industries that lean heavily on area scan include packaging and FMCG, automotive component cells, pharma secondary packaging, electronics, and general machine building. The common thread is a bounded FOV and a decision that can be made from a still (or motion-frozen) 2D image.
Datasheets are dense. Prioritize the list below in order. Megapixels alone rarely decide success.
Resolution is the number of pixels across the image (for example 1920×1200). Rough rule: to reliably measure or detect a feature, plan on several pixels across the smallest critical detail, often more if lighting or contrast is weak. Pixel size affects light sensitivity and how optics map millimeters on the part to pixels on the sensor. Higher resolution is not automatically better: it costs bandwidth, storage, and processing time, and may force a slower frame rate.
Sensor size must match the lens image circle. C-mount is common on industrial area scan cameras; larger sensors may need other mounts. Undersizing the lens for the sensor causes vignetting; oversizing can waste optics budget. Treat camera + lens as one optical design.
Maximum frame rate falls as resolution and bit depth rise, and as the interface saturates. If takt time needs 30 good images per second at full resolution, verify that number under your pixel format, not only the marketing “max fps” at a tiny ROI. Using a region of interest (ROI) is a legitimate way to go faster when you only care about part of the sensor.
Mono cameras generally deliver higher effective resolution and sensitivity for the same sensor class, prefer mono for metrology, code reading with controlled light, and most defect detection. Choose color when the defect or class is defined by color (wrong wire color, print color, material tint) or when operators need a natural image. Bayer color interpolates; do not assume color equals “more information” for every task.
GigE Vision is the workhorse for machine builders: long cables (typically up to ~100 m with appropriate networking), easy multi-camera topologies, and industrial switches. USB3 Vision is excellent for short runs, lab setups, and compact machines near the PC, simpler cabling, but length and hub behavior need care. Camera Link and CoaXPress serve higher bandwidth or specialized lines. Pick the interface for cable plant and PC architecture, not brand preference.
Global shutter exposes all pixels at once, preferred when parts move during exposure. Rolling shutter reads lines sequentially and can skew fast motion. Many modern CMOS area scan cameras offer global shutter; confirm it if conveyors or robots move during the flash.
The best camera cannot fix bad contrast. Ring, bar, backlight, dome, and strobe geometries decide whether a scratch appears. Budget time for lighting trials, start from our lighting page when you design the station.
A reliable station is a system, not a SKU:
On Sedeco product pages for area scan families you will typically see options such as sensor model, resolution, and max. frame rate, plus interface cues in the SKU or specifications (GigE vs USB, mono vs color). Read them as answers to the eight questions above:
When you evaluate “area scan camera,” that phrase can link here so you can understand the category before comparing models in the camera catalogue.
Suppose you inspect a molded cover that is 80 mm wide in the field of view. The critical defect is a 0.4 mm flash on the edge. You want at least 5 pixels across that flash so detection is stable when contrast varies.
Required spatial sampling: 0.4 mm / 5 pixels = 0.08 mm per pixel. Across 80 mm you need 80 / 0.08 = 1000 pixels of width, so a 1.3 MP (for example 1280×1024) sensor can work if the FOV is tight and optics are sharp. If the FOV must be 160 mm to tolerate part placement, you need about double the horizontal pixels, or a different optical layout (two cameras, or accept coarser sampling).
This is why buying megapixels by habit is not a strategy. Start from feature size, FOV, and pixels-on-feature. Then confirm with real samples under real lighting. Sedeco often runs a short feasibility pass for exactly this reason, see the feasibility checklist.
Rule of thumb
µm/pixel ≈ (FOV width in µm) / (sensor pixels used across that width). Your smallest reliable feature should span multiple pixels after optics MTF and lighting are included, not only in a calculation.
Area scan shows up differently by sector. The sensor family stays the same; the lighting and acceptance criteria change.
Label presence, date-code OCR, seal integrity cues, fill-level windows, and carton assembly checks. Parts move on conveyors; strobe lighting and global shutter keep edges crisp. Color may matter for brand artwork; mono often wins for codes and geometry.
Clip seating, thread presence, gasket position, pore or scratch checks on machined faces. Stations are often robot-fed with tight takt. Calibration and stable mounts matter as much as megapixels when you gauge in 2D.
Connector pin count and coplanarity cues (sometimes better with 3D), polarity marks, PCB feature checks, and solder cues with coaxial or dome light. High resolution and good lenses are common; heat and ESD practices affect housing choice.
Leaflet presence, carton codes, aggregation support, and print verification. Validation and recipe control dominate the project, the camera must be reproducible, not merely impressive on a datasheet alone.
You standardize on a camera family (often GigE area scan) across machines shipped worldwide. GenICam compatibility, PoE options, and long-term availability weigh as heavily as peak fps. Document the optical recipe so field service can repeat it.
An area scan camera rarely stands alone. Typical industrial loops look like this:
Latency budgets matter: image transfer + algorithm + handshake must fit inside takt with margin. Multi-camera GigE systems need switch quality and NIC tuning; USB3 systems need short, reliable cabling and attention to host controllers.
If you are unsure whether processing should live on a smart camera or a PC, settle that architecture question before freezing the area-scan SKU, again via the smart vs PC decision page.
Teams sometimes under-buy optics and lighting to save on the camera, then spend months fighting false rejects. The inverse also happens: an expensive sensor with a kit lens and ambient light. Image quality is a chain; the weakest link sets the false-reject rate.
Practical budgeting for a first station often allocates meaningful spend to lighting and mechanics, mounts, enclosures, cable management, not only to the camera body. A stable 5 MP GigE mono camera with the right ring light and lens routinely outperforms a much higher-megapixel camera in uncontrolled light.
Define acceptance with samples: golden parts, borderline fails, and dirty or reflective variants. If you cannot show the defect to a human under the proposed lighting, software will struggle too.
In everyday language, often yes, but Computer Vision also includes line scan, 3D, and smart cameras. Area scan specifically means a 2D matrix sensor capturing a full frame per exposure.
When product moves continuously at high speed and you need fine defects along a long web or strip, or when a single area-scan FOV cannot cover the width at the required resolution.
Only if color is part of the decision. Otherwise mono is usually sharper and more light-efficient for industrial inspection.
GigE for longer cables and multi-camera machines; USB3 for short distances and simple single-camera cells next to the PC. Bandwidth needs and PC ports also matter.
Yes, if resolution, optics, and lighting support both tasks, sometimes in one recipe, sometimes as sequential inspections. Extremely demanding code reading may still warrant a dedicated reader.
Start from the smallest feature and required pixels across it, then compute sensor resolution from FOV. Validate on real samples; do not buy “the highest MP” by default.
Most industrial models follow GenICam / GigE Vision or USB3 Vision and work with vendor SDKs or independent libraries. Smart cameras use onboard environments; PC-based systems use full vision packages.
You now have the category model: area scan captures a full 2D frame for discrete inspection, measurement, ID, and guidance, provided optics and lighting are designed with the camera.
Area scan, line scan, smart and 3D, choose the family before the SKU.
FOV, working distance and distortion for your sensor format.
Backlight, ring, dome, bar and strobe for stable contrast.
Send part size, takt and samples, we help select the stack.
Related knowledge hub: Kennis / Knowledge. Continue with line scan, 3D cameras, smart cameras, code readers, lenses and lighting.