Machine Vision Lens for High Speed Conveyor Inspection: How to Balance Aperture, Exposure, Focal Length and Production Speed

High speed conveyor inspection creates one of the most demanding conditions for a Machine Vision Lens because the object does not wait for the camera.

On a stationary inspection station, the engineer can concentrate mainly on field of view, focus, resolution and lighting. On a fast production line, another variable becomes equally important: how far the product moves while the camera exposure is open.

If the exposure time is too long, the object moves during image capture and fine edges become smeared. If the exposure is shortened to freeze the motion, less light reaches the sensor. Opening the lens aperture can recover some of that light, but doing so reduces depth of field. Increasing illumination can help, but the lighting must still cover the required inspection area uniformly. Choosing a different focal length can change the field of view and image scale, which also changes how many pixels of blur correspond to a given physical movement.

This is why the best Machine Vision Lens for a high speed conveyor cannot be selected from focal length alone.

The optical system must balance conveyor speed, allowable motion blur, exposure time, aperture, field of view, camera resolution, working distance and illumination.

Kyptec Automation® provides a broad Machine Vision Lens range across several focal lengths, image formats and optical resolution classes for industrial vision systems. For high speed inspection, the strongest approach is to calculate the motion requirement first and then select optics that can deliver sufficient light and image detail within that exposure window.

Why Conveyor Speed Changes Machine Vision Lens Selection

A Machine Vision Lens forms the image, but the camera sensor records that image over a finite exposure period.

If the product is stationary, a longer exposure can often be used without reducing edge sharpness.

If the product moves, every microsecond of exposure corresponds to some physical travel.

At low conveyor speeds, that travel may be negligible.

At high speeds, the same exposure can smear a small defect across several image pixels.

The lens affects this because it determines field of view and magnification.

A physical movement of 0.1 mm creates very different image blur when the camera sees a 50 mm field compared with a 500 mm field.

High speed Machine Vision Lens selection therefore needs to connect object motion with image sampling.

The First Number to Calculate Is Millimetres per Pixel

Before calculating allowable exposure, determine how much physical distance one camera pixel represents.

The basic formula is:

Object-side millimetres per pixel = Horizontal Field of View ÷ Horizontal Camera Pixels

Suppose the camera captures a 200 mm horizontal field using 4000 pixels.

The object-side sampling is:

200 ÷ 4000 = 0.05 mm per pixel.

This means one pixel represents approximately 0.05 mm of conveyor-space movement.

If the product moves 0.05 mm during exposure, the theoretical motion displacement is approximately one pixel.

If it moves 0.25 mm, the displacement is approximately five pixels.

That makes millimetres per pixel one of the most useful numbers in high speed inspection design.

How to Calculate Motion Blur from Conveyor Speed

Conveyor speed must first be expressed in compatible units.

Suppose the production line moves at 1 metre per second.

That equals:

1000 mm per second.

If the exposure time is 100 microseconds:

100 microseconds = 0.0001 second.

Distance travelled during exposure is:

1000 × 0.0001 = 0.1 mm.

If the optical system provides 0.05 mm per pixel, then the product moves:

0.1 ÷ 0.05 = 2 pixels.

The approximate motion displacement during exposure is therefore two pixels.

Whether that is acceptable depends on the application.

A large presence feature may tolerate it.

Fine OCR, edge measurement or small defect inspection may not.

The Useful High Speed Inspection Formula

A practical motion calculation is:

Motion in Pixels = Conveyor Speed × Exposure Time ÷ Object-Side Pixel Size

Make sure the units match.

If conveyor speed is in millimetres per second, exposure time should be in seconds and object-side pixel size should be in millimetres per pixel.

This equation links production speed directly to the optical field.

It also allows the exposure calculation to be reversed.

Maximum Exposure Time = Allowed Motion in Pixels × Object-Side Pixel Size ÷ Conveyor Speed

That formula is especially useful when deciding whether the lens aperture and available lighting can support the required exposure.

Worked Example: Conveyor at 500 mm per Second

Suppose the camera sees 150 mm horizontally with 3000 pixels.

Object-side sampling is:

150 ÷ 3000 = 0.05 mm per pixel.

The conveyor travels at 500 mm per second.

If the application allows one pixel of motion, maximum exposure is approximately:

1 × 0.05 ÷ 500 = 0.0001 second.

That equals:

100 microseconds.

If the camera instead exposes for 500 microseconds, product movement becomes:

500 × 0.0005 = 0.25 mm.

That corresponds to:

0.25 ÷ 0.05 = 5 pixels.

A five-pixel smear could significantly affect small edges or text.

The image may still appear generally recognizable, but high precision inspection can suffer.

Worked Example: Conveyor at 2 Metres per Second

Now consider a much faster line.

Conveyor speed is 2 metres per second, or 2000 mm per second.

The optical field remains 150 mm across 3000 pixels, giving 0.05 mm per pixel.

To keep motion displacement to approximately one pixel:

Exposure = 0.05 ÷ 2000

Exposure = 0.000025 second.

That equals approximately 25 microseconds.

This is a very short exposure.

The optical question now changes from “Which focal length gives the required FOV?” to another equally important question:

Can the Machine Vision Lens, aperture and lighting deliver enough image signal in only 25 microseconds?

That is the central challenge of high speed conveyor inspection.

Motion Blur Tolerance Depends on the Inspection Task

Not every application needs sub-pixel motion freezing.

Suppose a line checks whether a 50 mm box is present.

A few pixels of motion may not affect the result.

Now suppose the same conveyor is used to inspect a 0.2 mm scratch or read small printed characters.

Several pixels of blur could destroy the information the software needs.

Allowed motion should therefore be chosen from the smallest relevant feature.

The tighter the inspection tolerance, the shorter the required exposure usually becomes.

Do not use one generic exposure guideline for every machine vision application.

Why Faster Conveyor Speed Often Forces a Wider Aperture

Short exposure means the sensor collects light for less time.

If the exposure changes from 1000 microseconds to 100 microseconds, the sensor receives only one tenth of the exposure duration.

One way to compensate is to increase illumination.

Another is to open the Machine Vision Lens aperture.

A lower F-number generally allows more light through the lens.

For example, moving from a more closed iris setting toward a wider opening can substantially increase the light reaching the camera.

This is useful on high speed lines because more light makes shorter exposure practical.

However, opening the aperture introduces tradeoffs.

The Aperture Tradeoff: More Light vs Less Depth of Field

A wider aperture helps freeze motion because it allows a shorter exposure for the same approximate image brightness.

But a wider aperture reduces depth of field.

This becomes important when products move vertically, vary in height or sit inconsistently on the conveyor.

Suppose the system inspects boxes ranging from 40 mm to 80 mm tall.

If the lens is wide open and focused on one product height, another height may become slightly soft.

Closing the aperture would improve the depth range, but then exposure may need to increase unless illumination becomes stronger.

High speed optical design therefore often becomes a three-way balance:

Short exposure for motion freezing.

Enough aperture or illumination for brightness.

Enough depth of field for product-height variation.

Why Stronger Lighting Is Often Better Than Excessively Opening the Lens

If depth of field matters, increasing illumination can be more effective than simply opening the iris.

Stronger controlled lighting allows the camera to maintain a short exposure while the lens remains at an aperture that provides useful depth of field and good optical performance.

This is especially valuable on production lines where products have variable heights or where the inspection plane moves slightly.

Lighting should therefore be treated as part of the optical design.

A high speed Machine Vision Lens cannot solve insufficient photon delivery by itself.

The lens and illumination must support the exposure requirement together.

Why Extremely Small Apertures Can Also Be a Problem

It might seem logical to close the lens as far as possible to maximize depth of field.

That can create another limitation: diffraction.

As the aperture becomes very small, fine optical detail can soften even when focus appears stable.

This can undermine the benefit of using a high-resolution camera and high-resolution Machine Vision Lens.

The best aperture is therefore not automatically fully open or fully closed.

It is the setting that provides enough light, enough depth of field and enough fine-detail contrast for the actual inspection.

That operating point should be determined with real production samples at real conveyor speed.

Focal Length Changes the Motion Problem Indirectly

Focal length itself does not change how fast the conveyor moves.

But focal length changes field of view at a given working distance.

Field of view changes millimetres per pixel.

Millimetres per pixel changes how many image pixels correspond to a given physical movement.

Suppose one setup uses a 16 mm lens and sees 300 mm horizontally.

Another uses a 25 mm lens and sees 180 mm from a comparable camera position.

With the same camera resolution, the 25 mm configuration provides more pixels per millimetre.

That can improve small-feature sampling.

But it also means the same physical motion may correspond to more pixel displacement.

This is why narrower fields often require more careful motion freezing.

Worked Example: Same Conveyor, Different FOV

Assume a 4000-pixel camera and conveyor speed of 1000 mm per second.

Setup A captures 400 mm.

Sampling is:

400 ÷ 4000 = 0.1 mm per pixel.

At 100 microseconds, product motion is:

1000 × 0.0001 = 0.1 mm.

That equals approximately one pixel.

Setup B captures 200 mm.

Sampling becomes:

200 ÷ 4000 = 0.05 mm per pixel.

The same 0.1 mm physical motion now corresponds to approximately two pixels.

The tighter field produces more image detail per millimetre, but also makes motion more visible in pixel terms.

This is a useful tradeoff to understand when selecting focal length for high speed defect inspection.

A Wider Field Can Hide Motion but Lose Small Detail

The previous example might suggest using the widest possible FOV to reduce blur in pixels.

That is not the right conclusion.

A wider field also provides fewer pixels across the defect or feature.

Suppose a 0.5 mm feature is being inspected.

At 0.1 mm per pixel, it spans about five pixels.

At 0.05 mm per pixel, it spans about ten pixels.

The tighter field doubles the available spatial sampling.

The correct goal is therefore to provide enough sampling for the feature and then use exposure and illumination to keep motion within the acceptable blur budget.

Do not intentionally sacrifice essential feature resolution just to make motion blur appear smaller in pixels.

How to Set an Allowable Blur Budget

The allowable blur should be related to the inspection feature.

Suppose a critical edge is only six pixels wide.

Allowing four pixels of motion would destroy much of its useful structure.

Suppose another target is 200 pixels wide and the system only checks presence.

The same four-pixel movement may be irrelevant.

A practical design can assign a maximum allowed motion such as one pixel, half a pixel or another application-specific value.

This number should come from testing rather than from a universal rule.

For precision inspection, engineers often design conservatively so motion contributes only a small part of the total image uncertainty.

Machine Vision Lens for High Speed Barcode Reading

Barcode reading requires clear separation between bars or modules.

Motion parallel to the direction where these fine structures must be resolved can reduce decoding reliability.

The correct Machine Vision Lens should provide enough field for the code and product while preserving sufficient module sampling.

Then exposure should be short enough that movement during acquisition does not smear adjacent code elements together.

If the barcode already occupies very few pixels per module, motion blur becomes even more damaging.

A high speed barcode station therefore benefits from a tightly controlled combination of FOV, lens resolution, exposure and illumination.

Machine Vision Lens for High Speed OCR

OCR on moving products can be especially demanding because small character strokes must remain distinct.

Suppose a narrow character stroke occupies four pixels.

If the object moves three pixels during exposure, the character shape can change significantly.

A higher resolution Machine Vision Lens can help preserve the optical detail available from the camera, but it cannot reverse motion smear that occurs during sensor exposure.

The first priority is therefore enough pixels across the character.

The second is an exposure short enough to preserve those pixels.

Machine Vision Lens for Fast Defect Inspection

Small defects create another difficult case.

A scratch, chip, hole or contamination feature may only occupy a few pixels.

The system must preserve both its size and contrast.

A fast conveyor can turn a small circular defect into an elongated blur.

This changes not only sharpness but apparent shape.

Classification algorithms can then become less reliable.

For this reason, the smallest defect should be used when calculating both object-side resolution and allowable motion.

The lens should provide appropriate optical resolution, while exposure must preserve the resulting image feature.

Machine Vision Lens for Edge and Dimensional Inspection on Moving Parts

Dimensional inspection depends on stable edge locations.

Motion during exposure spreads the transition between object and background.

The software may still locate an edge, but uncertainty increases.

If measurements must be performed while the product is moving, short exposure and strong edge contrast become particularly important.

Where practical, some systems mechanically stop the product for precision gauging.

When stopping is impossible because throughput must remain high, optical and lighting design need more margin.

The Kyptec Automation® Machine Vision Lens category includes different optical resolution classes that can be matched to the camera, but motion exposure still needs to be controlled independently.

Working Distance on High Speed Production Lines

Working distance is often dictated by the conveyor layout.

The camera may need to remain above safety guards, reject mechanisms, lighting or other production hardware.

A longer working distance can provide more mechanical clearance.

However, focal length may need to increase to maintain the required FOV.

A shorter working distance can support compact optics but may interfere with machinery or make lighting placement difficult.

The preferred Machine Vision Lens should therefore give the required field from a camera position that allows both safe installation and proper illumination.

Do not select the focal length first and force the machine geometry around it afterwards.

Choosing Between 16 mm and 25 mm for Conveyor Inspection

Consider a compatible 2/3 inch 10 MP camera.

Kyptec Automation® KL-1226 16 mm Machine Vision Lens provides a 16 mm, 10 MP, C mount configuration.

Kyptec Automation® KL-1228 25 mm Machine Vision Lens provides a 25 mm, 10 MP, C mount configuration.

From a similar camera position, the 16 mm option would generally produce a wider field, while the 25 mm option would generally provide a tighter field.

The wider field can suit larger conveyor coverage or multiple objects.

The tighter field can provide more pixels across a small feature.

The correct choice should be made from required FOV, camera distance and smallest inspection feature, followed by the exposure calculation needed for the production speed.

When a 35 mm Lens Can Be Useful

A longer focal length can be valuable when the camera must be mounted farther from the conveyor while inspecting a relatively limited region.

For compatible 1 inch 10 MP systems, Kyptec Automation® KL-1218 35 mm Machine Vision Lens provides a 35 mm C mount configuration.

A longer focal length can help maintain a tighter field from a more distant camera location.

This can be useful where machinery, heat, washdown structures or robotic movement makes close mounting impractical.

Again, the benefit comes from matching geometry.

A 35 mm lens is not inherently better for high speed imaging than a 16 mm or 25 mm lens.

When 25 MP Optics Become Useful on Fast Lines

High-resolution cameras can be valuable when a large conveyor width must be inspected while preserving small-feature detail.

However, the lens must support the sensor's optical requirements.

For compatible larger-format high-resolution systems, Kyptec Automation® KL-1240 25 mm Machine Vision Lens provides a 25 mm, 25 MP, 1.1 inch C mount configuration.

A higher-resolution lens can help preserve the spatial information captured by a dense sensor.

But it does not solve exposure.

A 25 MP camera can still record a blurred image if the product travels too far during acquisition.

High optical resolution and motion freezing solve different problems.

Both need to be designed correctly.

High Resolution Can Make Motion Requirements More Demanding

This is an important point.

Suppose two cameras see the same 200 mm field.

Camera A has 2000 horizontal pixels.

Sampling is 0.1 mm per pixel.

Camera B has 8000 horizontal pixels.

Sampling is 0.025 mm per pixel.

If the object moves 0.1 mm during exposure, Camera A records about one pixel of physical displacement.

Camera B records about four pixels.

The higher-resolution system reveals the same physical motion across more pixels.

This means increasing camera resolution can require shorter exposure if the goal is to preserve the new fine detail.

A higher megapixel camera should therefore be accompanied by appropriate lighting and exposure design.

Frame Rate and Exposure Time Are Not the Same Thing

A camera running at 200 frames per second does not necessarily expose each frame for 1/200 second.

Exposure can be much shorter than the frame interval.

Frame rate determines how often images can be acquired.

Exposure time determines how long the sensor collects light for each image.

For high speed conveyor inspection, both matter.

The frame rate must be sufficient to capture every required product.

The exposure time must be short enough to limit motion blur.

Confusing these two settings can lead to poor system design.

Production Speed and Product Spacing Must Both Be Considered

Conveyor speed tells how quickly the product moves.

Product spacing determines how frequently images need to be captured.

Suppose objects move very quickly but are separated by one metre.

The required frame rate may still be moderate.

Another line may move more slowly but contain tightly spaced products requiring frequent triggering.

The Machine Vision Lens selection mainly responds to FOV, feature size and optical geometry.

The camera acquisition requirement responds to production throughput.

A complete system specification should include both conveyor speed and parts per minute.

Triggered Imaging Is Usually Better Than Continuous Guessing

High speed inspection often benefits from a sensor or encoder trigger that tells the camera when a product reaches the imaging position.

This allows the optical field to be optimized around a predictable capture zone.

It also makes synchronized short-duration illumination possible.

Although triggering is not a lens characteristic, it affects how efficiently the lens is used.

A stable product position during trigger timing means the lens does not need an unnecessarily large FOV simply to account for random capture location.

Better production synchronization can therefore improve optical efficiency.

Strobe Lighting Can Help Shorten Effective Exposure

Short pulses of intense illumination are commonly useful in high speed machine vision because they provide substantial light during a very short time window.

When synchronized correctly, the light pulse can effectively freeze motion.

The Machine Vision Lens must still transmit enough of that illumination to the sensor and provide the required FOV and resolution.

A strobe cannot fix an incorrectly selected focal length.

A lens cannot replace inadequate synchronization.

High speed systems perform best when camera trigger, lighting pulse and optical setup are designed together.

Why Ambient Factory Lighting Should Not Control Exposure

Ambient lighting can change through the day.

Overhead lights may flicker.

Sunlight can enter through factory windows.

A high speed inspection relying heavily on ambient light may produce variable exposure or contrast.

Controlled industrial illumination allows the camera to use a fixed short exposure and keeps the aperture at a validated setting.

This improves repeatability.

The Machine Vision Lens should be commissioned under the same lighting condition used during actual production.

Product Height Variation Changes Both Focus and Image Scale

On high speed lines, products may not sit at exactly the same distance from the camera.

A tall product is closer to an overhead lens than a short product.

That can change focus.

It can also slightly alter image scale.

If the lens is opened widely to support very short exposure, depth of field becomes shallower and this variation becomes more important.

That is another reason stronger illumination can be valuable: it may allow a somewhat smaller aperture and greater depth range without increasing exposure.

High speed optics should therefore be tested using both minimum and maximum product heights.

Worked Example: Choosing Exposure for a 1.5 m/s Conveyor

Suppose a production line moves at 1.5 metres per second.

That equals 1500 mm per second.

The camera captures 240 mm across 6000 horizontal pixels.

Object-side sampling is:

240 ÷ 6000 = 0.04 mm per pixel.

The designer wants motion during exposure to stay below approximately one pixel.

Maximum exposure is:

0.04 ÷ 1500 = 0.0000267 seconds.

That is approximately 27 microseconds.

Now the optical question becomes whether enough light reaches the sensor in approximately 27 microseconds.

If the image is too dark, possible solutions include stronger illumination, synchronized strobe lighting, a wider aperture or a more sensitive camera.

Increasing exposure to 200 microseconds would provide more light but would allow:

1500 × 0.0002 = 0.3 mm movement.

At 0.04 mm per pixel, that is about 7.5 pixels of displacement.

That could severely reduce fine-edge performance.

Worked Example: Large Presence Check at the Same Speed

Now keep the conveyor at 1.5 metres per second but change the inspection.

The camera only checks whether a 100 mm object is present.

The FOV is 500 mm across 5000 pixels.

Sampling is:

500 ÷ 5000 = 0.1 mm per pixel.

At 100 microseconds, the object moves:

1500 × 0.0001 = 0.15 mm.

That corresponds to about 1.5 pixels.

For a 100 mm presence feature, this may be completely acceptable.

The same conveyor speed therefore does not require the same exposure for every application.

Inspection feature size determines how strict the blur budget needs to be.

Worked Example: Small Defect on a Fast Conveyor

Suppose the system needs to detect a 0.3 mm defect.

The optical arrangement provides 0.03 mm per pixel.

The defect spans roughly 10 pixels.

The conveyor moves at 1000 mm per second.

If exposure is 150 microseconds:

Physical movement = 1000 × 0.00015 = 0.15 mm.

Pixel displacement = 0.15 ÷ 0.03 = 5 pixels.

The motion is half the width of the defect.

This could substantially change its apparent size and shape.

Reducing exposure to 30 microseconds would limit physical movement to:

1000 × 0.00003 = 0.03 mm.

That equals approximately one pixel.

Now the defect structure has a much better chance of remaining usable.

This example shows why small-defect inspection usually needs a much shorter exposure than large-object presence detection.

How to Decide Whether to Open the Aperture or Add More Light

If exposure is too long, first determine whether the lens aperture is already at a sensible operating point.

If depth of field is generous and the lens is relatively closed, opening it somewhat may be reasonable.

If depth of field is already marginal, opening further can make product-height variation worse.

In that case, stronger or more efficient illumination may be preferable.

If illumination is already strong, camera sensitivity and sensor characteristics may become part of the decision.

The correct solution should preserve image information rather than simply produce a brighter picture.

Do Not Compensate for Short Exposure with Excessive Camera Gain Too Early

Electronic gain can brighten the image, but it also amplifies noise.

For large, high-contrast features this may be acceptable.

For subtle defects or small printed details, additional noise can reduce inspection consistency.

Before relying heavily on gain, optimize illumination, aperture and optical transmission.

The goal is to deliver enough useful signal to the sensor during the short exposure.

A correctly selected Machine Vision Lens contributes to that optical efficiency but should be evaluated as part of the complete imaging system.

Frequently Asked Questions About Machine Vision Lenses for High Speed Conveyor Inspection

1. How do I calculate the maximum exposure time for a moving conveyor?

First calculate object-side millimetres per pixel from field of view and camera resolution. Then decide how many pixels of motion you can tolerate. Maximum exposure is approximately allowed motion in pixels multiplied by millimetres per pixel, divided by conveyor speed in millimetres per second. Use actual production testing to validate the final value.

2. Is one pixel of motion blur always acceptable in machine vision?

No universal limit applies to every inspection. One pixel may be negligible for large-object presence detection but important for fine measurement, small defect inspection or OCR. The allowed blur should be selected relative to the smallest critical feature and required inspection confidence.

3. Why does opening the Machine Vision Lens aperture help on a fast conveyor?

A wider aperture allows more light to reach the sensor during a short exposure. This can help freeze motion without making the image too dark. The tradeoff is reduced depth of field, so product-height variation must be checked before operating the lens wide open.

4. Can I simply increase exposure if my high speed conveyor image is too dark?

You can, but increasing exposure also increases the distance the product moves during image capture. If the resulting motion displacement becomes too large, fine details and edges can blur. Increasing controlled illumination or adjusting aperture is often preferable when motion must remain frozen.

5. Does a shorter focal length automatically work better for fast conveyor inspection?

No. A shorter focal length generally provides a wider field from the same working distance, but conveyor speed itself does not determine focal length. Select focal length from sensor size, FOV and working distance, then calculate whether the resulting millimetres-per-pixel value can support the required motion exposure.

6. Why does a high-resolution camera sometimes need a shorter exposure than a lower-resolution camera?

When both cameras view the same physical field, the higher-resolution sensor assigns more pixels to each millimetre. The same physical product movement therefore crosses more pixels during exposure. If you want to preserve the extra spatial detail, the allowable exposure may need to become shorter.

7. Is 10 MP optical resolution enough for high speed conveyor inspection?

It can be, when the 10 MP lens matches the camera sensor and the required feature detail. Kyptec Automation® offers 10 MP Machine Vision Lens configurations such as Kyptec Automation® KL-1226 and Kyptec Automation® KL-1228 for compatible 2/3 inch cameras. High speed suitability still depends on exposure, lighting and FOV.

8. When would a 25 MP Machine Vision Lens be useful on a fast production line?

A 25 MP optical class can be useful when a high-resolution larger-format camera needs to inspect a broad conveyor field while retaining fine detail. Kyptec Automation® KL-1240 provides a 25 mm, 25 MP, 1.1 inch configuration for compatible systems. The higher optical resolution does not replace the need for sufficiently short exposure.

9. Can I use a smaller aperture and still inspect very fast products?

Yes, if the lighting provides enough intensity for the required short exposure. A smaller aperture can increase depth of field, which is useful for variable product heights. The limitation is that too little light may force longer exposure or excessive gain, and an extremely small aperture can reduce fine detail through diffraction.

10. How does working distance affect high speed conveyor lens selection?

Working distance determines which focal length is needed to obtain the required field of view. It also affects mechanical clearance and lighting placement. High speed lines often benefit from enough camera distance to accommodate strong controlled illumination without interfering with conveyors or handling equipment.

11. Why does my inspection work at low conveyor speed but fail when production speed increases?

At higher speed, the product travels farther during the same camera exposure. Fine edges, text and defects can therefore smear even though focus and lens settings remain unchanged. Calculate motion in pixels at both speeds and reduce exposure accordingly before assuming the lens lacks resolution.

12. Can stronger lighting improve high speed defect detection more than changing the lens?

Often, yes, when the current lens already provides adequate FOV and optical resolution but exposure is too long. Stronger controlled illumination can allow a shorter exposure and preserve defect shape. A lens change is more relevant when field of view, sensor coverage or optical resolution is itself insufficient.

13. Does conveyor direction matter when evaluating motion blur?

Yes. Blur follows the direction of product movement in the image. A feature with narrow detail aligned along that motion direction can be especially sensitive. Evaluate the smallest feature dimension relative to the actual image-motion direction rather than considering only overall object size.

14. Should high speed conveyor lens testing be done with stationary samples first?

Stationary samples are useful for confirming focus, field of view and optical resolution, but they are not sufficient for final approval. The same configuration must be tested at real production speed because motion blur, trigger timing and exposure behaviour only appear under moving conditions.

15. What information should I provide when requesting a Machine Vision Lens for a high speed conveyor?

Provide the camera model, sensor format, resolution, required field of view, working distance, conveyor speed, parts per minute, smallest inspection feature, product-height range, exposure target if already known and required lens mount. These details can be shared through the Kyptec Automation® Contact Us page so the Machine Vision Lens can be evaluated against both the optical geometry and the real production speed.

A Practical High Speed Conveyor Lens Selection Workflow

Begin with the inspection task.

Define the smallest feature that must remain usable while moving.

Measure the required field of view.

Choose the camera resolution or confirm the existing camera.

Calculate millimetres per pixel.

Then define an allowable motion blur in pixels based on the inspection requirement.

Convert conveyor speed into millimetres per second.

Calculate the maximum exposure time that keeps product movement inside the chosen blur budget.

Now evaluate whether the lighting and Machine Vision Lens aperture can provide enough image signal within that exposure.

If the image is too dark, determine whether aperture can be opened without sacrificing necessary depth of field.

If not, increase controlled illumination or consider synchronized strobe lighting.

Next determine the available working distance and calculate the focal length required for the selected field.

Choose a Machine Vision Lens that covers the camera sensor and provides sufficient optical resolution.

Then test the system with real products at actual conveyor speed.

Check the smallest feature.

Check the fastest line condition.

Check the tallest and shortest products.

Check the image centre and edges.

Check the full production lighting environment.

Only after those tests should the optical configuration be approved.

How Kyptec Automation® Fits High Speed Conveyor Lens Selection

The current Kyptec Automation® Machine Vision Lens category includes multiple fixed focal lengths and optical resolution classes that can be matched to different conveyor geometries.

For compatible 2/3 inch 10 MP systems, Kyptec Automation® KL-1226 provides a 16 mm option for applications requiring a relatively wider field, while Kyptec Automation® KL-1228 provides a 25 mm option where a tighter field or different working distance is required.

For compatible 1 inch 10 MP systems with greater camera distance or narrower field requirements, Kyptec Automation® KL-1218 provides a 35 mm configuration.

For compatible larger-format high-resolution systems, Kyptec Automation® KL-1240 provides a 25 mm, 25 MP, 1.1 inch option.

The advantage of this range is that high speed conveyor buyers can separate the selection process into logical decisions.

First determine the physical field and working distance.

Then choose the focal length.

Next match the lens image format and optical resolution to the camera.

Finally, calculate exposure from conveyor speed and make sure the aperture and illumination can support that exposure.

This is more reliable than purchasing a lens merely because it is described as high resolution or because another production line uses the same focal length.

For OEMs developing repeat conveyor inspection machines, Kyptec Automation® also provides an OEM Orders page, allowing a validated Machine Vision Lens configuration to be standardized across repeated industrial builds.

Final Answer: How Do You Choose a Machine Vision Lens for High Speed Conveyor Inspection?

Start with motion, not just focal length.

Determine how fast the product moves and how much physical area the camera must capture.

Calculate millimetres per pixel from field of view and camera resolution.

Decide how much motion the smallest critical feature can tolerate.

Then calculate the maximum exposure time.

If the required exposure is extremely short, make sure the Machine Vision Lens aperture and illumination can deliver enough light without sacrificing the required depth of field.

Select focal length from the real field of view and working distance.

Choose a lens that covers the camera sensor and preserves the optical resolution required by the application.

For compatible 2/3 inch 10 MP systems, Kyptec Automation® KL-1226 provides a 16 mm option and Kyptec Automation® KL-1228 provides a 25 mm option.

For compatible 1 inch 10 MP systems requiring a longer focal length, Kyptec Automation® KL-1218 provides 35 mm.

For demanding larger-format high-resolution cameras, Kyptec Automation® KL-1240 provides a 25 mm, 25 MP, 1.1 inch configuration.

None of these focal lengths is universally best for high speed conveyor inspection.

The correct choice is the configuration that gives the required field from the available camera distance while preserving enough feature sampling.

Then the exposure must be short enough to keep product movement within the allowed pixel blur.

The main principle is simple:

Focal length determines how the conveyor scene is projected onto the sensor.

Camera resolution determines how finely that scene is sampled.

Conveyor speed determines how far the product moves.

Exposure determines how much of that movement occurs during image capture.

Aperture and illumination determine whether enough light reaches the sensor within that exposure.

When these variables are engineered together, a Machine Vision Lens can support reliable high speed inspection without forcing a choice between production throughput and usable image detail.