Lighting Archives - Page 3 of 4 - 1stVision Inc.

November 2, 2022November 2, 2022

Components needed for machine vision and industrial imaging systems

Machine vision and industrial imaging systems are used in various applications ranging from automated quality control inspection, bottle filling, robot pick-and-place applications, autonomous drone or vehicle guidance, patient monitoring, agricultural irrigation controls, medical testing, metrology, and countless more applications.

Imaging systems typically include a least a camera and lens, and often also include one or more of specialized lighting, adapter cards, cables, software, optical filters, power supply, mount, or enclosure.

At 1stVision we’ve created a resource page is intended to make sure that nothing in a planned imaging application has been missed. There are many aspects on which 1stVision can provide guidance. The main components to consider are indicated below.

Cameras: There are area scan cameras for visible, infrared, and ultraviolet light, used for static or motion situations. There are line scan cameras, often used for high-speed continuous web inspection. Thermal imaging detects or measures heat. SWIR cameras can identify the presence or even the characteristics of liquids. The “best” camera depends on the part of the spectrum being sensed, together with considerations around motion, lighting, surface characteristics, etc.

**An assortment of lens types and manufacturers**

Lens: The lens focuses the light onto the sensor, mapping the targeted Field of View (FoV) from the real world onto the array of pixels. One must consider image format to pair a suitable lens to the camera. Lenses vary by the quality of their light-passing ability, how close to the target they can be – or how far from it, their weight (if on a robot arm it matters), vibration resistance, etc. See our resources on how to choose a machine vision lens. Speak with us if you’d like assistance, or use the lens selector to browse for yourself.

Lighting: While ambient light is sufficient for some applications, specialized lighting may also be needed, to achieve sufficient contrast. And it may not just be “white” light – Ultra-Violet (UV) or Infra-Red (IR) light, or other parts of the spectrum, sometimes work best to create contrast for a given application – or even to induce phosphorescence or scatter or some other helpful effect. Additional lighting components may include strobe controllers or constant current drivers to provide adequate and consistent illumination. See also Lighting Techniques for Machine Vision.

Optical filter: There are many types of filters that can enhance application performance, or that are critical for success. For example a “pass” filter only lets certain parts of the spectrum through, while a “block” filter excludes certain wavelengths. Polarizing filters reduce glare. And there are many more – for a conceptual overview see our blog on how machine filters create or enhance contrast.

Don’t forget about interface adapters like frame grabbers and host adapters; cables; power supplies; tripod mounts; software; and enclosures. See the resource page to review all components one might need for an industrial imaging system, to be sure you haven’t forgotten anything.

1st Vision’s sales engineers have over 100 years of combined experience to assist in your camera and components selection. With a large portfolio of lenses, cables, NIC card and industrial computers, we can provide a full vision solution!

January 21, 2022January 21, 2022

How machine vision filters create contrast in machine vision applications

Imaging outcomes depend crucially on contrast. It is only by making a feature “pop” relative to the larger image field in which the feature lies, that the feature can be optimally identified by machine vision software.

While sensor choice, lensing, and lighting are important aspects in building machine vision solutions with effective contrast creation, effective selection and application of filters can provide additional leverage for many applications. Often overlooked or misunderstood, here we provide a first-look at machine vision filter concepts and benefits.

In the 4 image pairs above, each left-half image was generated with the same sensor, lighting, and exposure duration as the corresponding right-half images. But the right-half images have had filters applied to reduce glare or scratch-induced scatter, separate or block certain wavelengths, for example. If your brain finds the left-half images to be difficult to discern, image processing software wouldn’t be “happy” with the left-half either!

While there are also filtering benefits in color and SWIR imaging, it is worth noting that we started above with examples shown in monochrome. Surprising to many, it can often be both more effective and less expensive to create machine vision solutions in the monochrome space – often with filters – than in color. This may seem counter-intuitive, since most humans enjoy color vision, and use if effectively when driving, judging produce quality, choosing clothing that matches our skin tone, etc. But compared to using single-sensor color cameras, monochrome single sensor cameras paired with appropriate filters:

can offer higher contrast and better resolution
provide better signal-to-noise ratio
can be narrowed to sensitivity in near-ultraviolet, visible and near-infrared spectrums

These features give monochrome cameras a significant advantage when it comes to optical character recognition and verification, barcode reading, scratch or crack detection, wavelength separation and more. Depending on your application, monochrome cameras can be three times more efficient than color cameras.

Color cameras may be the first thought when separating items by color, but it can be more efficient and effective to use a monochrome camera with a color bandpass filter. As shown above, to brighten or highlight an item that is predominantly red, using a red filter to transmit only the red portion of the spectrum can be used, blocking the rest of the transmitted light. The reverse can also work, using a blue filter to pass blue wavelengths while blocking red and other wavelengths.

Here we have touched on just a few examples, to whet the appetite. We anticipate developing a Tech Brief with a more in depth treatment of filters and their applications. We partner with Midwest Optical to offer you a wide range of filters for diverse application solutions.

1st Vision’s sales engineers have an average of 20 years experience to assist in your camera selection. Representing the largest portfolio of industry leading brands in imaging components, we can help you design the optimal vision solution for your application.

About Us | 1stVision

1st Vision is the most experienced distributor in the U.S. of machine vision cameras, lenses, frame grabbers, cables, lighting, and software in the industry.

May 26, 2021June 7, 2021

Types of 3D imaging systems – and benefits of Time of Flight (ToF)

2D imaging is long-proven for diverse applications from bar code reading to surface inspection, presence-absence detection, etc. If you can solve your application goal in 2D, congratulations!

But some imaging applications are only well-solved in three dimensions. Examples include robotic pick and place, palletization, drones, security applications, and patient monitoring, to name a few.

For such applications, one must select or construct a system that creates a 3D model of the object(s). Time of Flight (ToF) cameras from Lucid Vision Labs is one way to achieve cost-effective 3D imaging for many situations.

ToF systems setup — ToF systems have a light source and a sensor.

ToF is not about objects flying around in space! It’s about using the time of flight of light, to ascertain differences in object depth based upon measurable variances from light projected onto an object and the light reflected back to a sensor from that object. With sufficiently precise orientation to object features, a 3D “point cloud” of x,y,z coordinates can be generated, a digital representation of real-world objects. The point cloud is the essential data set enabling automated image processing, decisions, and actions.

In this latest whitepaper we go into depth to learn:

1. Types of 3D imaging systems

2. Passive stereo systems

3. Structured light systems

4. Time of Flight systems

Whitepaper table of contents

Let’s briefly put ToF in context with other 3D imaging approaches:

Passive Stereo: Systems with cameras at a fixed distance apart, can triangulate, by matching features in both images, calculating the disparity from the midpoint. Or a robot-mounted single camera can take multiple images, as long as positional accuracy is sufficient to calibrate effectively.

Challenges limiting passive stereo approaches include:

Occlusion: when part of the object(s) cannot be seen by one of the cameras, features cannot be matched and depth cannot be calculated.

ToF diagram — Occlusion occurs when a part of an object cannot be imaged by one of the cameras.

Few/faint features: If an object has few identifiable features, no matching correspondence pairs may be generated, also limiting essential depth calculations.

Structured Light: A clever response to the few/faint features challenge can be to project structured light patterns onto the surface. There are both active stereo systems and calibrated projector systems.

Active stereo systems are like two-camera passive stereo systems, enhanced by the (active) projection of optical patterns, such as laser speckles or grids, onto the otherwise feature-poor surfaces.

Calibrated projector systems use a single camera, together with calibrated projection patterns, to triangulate from the vertex at the projector lens. A laser line scanner is an example of such a system.

Besides custom systems, there are also pre-calibrated structured light systems available, which can provide low cost, highly accurate solutions.

Time of Flight (ToF): While structured light can provide surface height resolutions better than 10μm, they are limited to short working distances. ToF can be ideal for or applications such as people monitoring, obstacle avoidance, and materials handling, operating at working distances of 0.5m – 5m and beyond, with depth resolution requirements to 1 – 5mm.

ToF systems measure the time it takes for light emitted from the device to reflect off objects in the scene and return to the sensor for each point of the image. Some ToF systems use pulse-modulation (Direct ToF). Others use continuous wave (CW) modulation, exploiting phase shift between emitted and reflected light waves to calculate distance.

The new Helios ToF 3D camera from LUCID Vision Labs, uses Sony Semiconductor’s DepthSense 3D technology. Download the whitepaper to learn of 4 key benefits of this camera, example applications, as well as its operating range and accuracy,

Have questions? Tell us more about your application and our sales engineer will contact you.

1st Vision’s sales engineers have an average of 20 years experience to assist in your camera selection. Representing the l argest portfolio of industry leading brands in imaging components, we can help you design the optimal vision solution for your application.

January 14, 2021January 15, 2021

Ultra-Uniform lighting provides enhanced contrast for machine vision

The old saying of a chain is only as strong as its weakest link stands true in machine vision applications. A machine vision hardware solution typically consists of a camera, lens, and light to obtain an image for processing. If anyone of these components are improperly selected, its the weakest. Lighting is a key component to produce features and contrast for image processing. Uniformity, brightness, wavelength and specific geometries used in conjunction with each other are key elements to a good lighting component. In this blog, we introduce Phlox machine vision lighting, which is unsurpassed in uniformity and has many key advantages.

Phlox lighting provided much more than just lighting, regardless of the application. Below are 5 main attributes making Phlox unique

1 – Better uniformity: A precise mathematical model and the micro prisms (< 30 µ) enable us to reach up to +/- 5 % uniformity for the backlight surface.

2 – Higher luminance: Up to 80% of the light injected is emitted onto the target surface, up to twice as much as light pipes using diffusion.

3 – More compact design: Phlox technology is well suited to the manufacture of very thin pipes (1 mm). This feature enables Phlox to create very low profile (very thin) products in response to the need to reduce bulk for various applications.

4 – Long life cycle: The combination of Phlox technology and the quality of the designs ensures constant control of temperature and provides an exceptional life cycle.

5 – Faster response: Fast delivery of a standard products and five (5) weeks on average to design and delivery of a prototype or custom-made product.

How do Phlox back lights compare to the competition?

The following are application examples showing the increased contrast generated by Phlox back lights:

Phlox image comparison — Gear profile is prominent

In conjunction with the unparalleled uniformity, Phlox lighting can be configured with a variety of wavelengths optimizing contrast as seen in the examples below.

solve any application with the right wavelength

Phlox uses exclusive technology, providing many key advantages along with a 2-year warranty

Phlox technology — Watch this short video detailing the engraving process

1stVision is the exclusive distributor in North America for Phlox product. Contact us to discuss your application with our experienced technical advisors – CLICK HERE

1st Vision’s sales engineers have an average of 20 years experience to assist in your camera selection. Representing the largest portfolio of industry leading brands in imaging components, we can help you design the optimal vision solution for your application.