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Telecentric lenses – Edmund Optics SilverTL and CobaltTL Series

While a standard lens is adequate or even ideal for many machine vision applications, there is inherent distortion in a standard lens, often in the range of 1 – 2%. Telecentric lenses achieve distortion of 0.1% or less. They also provide constant magnification and no perspective error.

If you “just” need presence/absence detection, or counting discreet non-occluded objects, a conventional lens may be fine. But if you need highly accurate contactless measurement, telecentric lenses offer remarkable performance.

CobaltTL Telecentric Lens with In-Line Illumination –
Courtesy Edmund Objects

Let’s take a brief look at what qualifies a lens as telecentric, and why you might want (or need) one. Subsequently we’ll summarize Edmund Optics SilverTLTM and CobaltTLTM lens series.

Telecentric Tutorial

Telecentric lenses only accept incoming light rays that are parallel to the optical axis of the lens. It’s not that the oblique rays don’t reach the outer edge of the telecentric lens. Rather, it’s about the optical design of the lens in terms of what it passes on through the other lens elements and onto the sensor focal plane.

Hmm, but the telecentric lens must have a narrower Field of View (FoV) – and I have to pay a premium for that? Well yes – and yes. There are certain benefits.

Let’s get to an example. In the image immediately below, labeled “Setup”, we see a pair of cubes positioned with one forward of the other. This image was made with a conventional (entocentric) lens, whereby all three dimensions appear much the same as for human vision. It looks natural to us because that’s what we’re used to. And if we just wanted to count how many orange cubes are present, the lens used to make the setup image is probably good enough.

Courtesy Edmund Optics
Courtesy Edmund Optics.

But suppose we want to measure the X and Y dimensions of the cubes, to see if they are within rigorous tolerance limits?

An object-space telecentric lens focuses the light without the perspective of distance. Below, the image on the left is the “straight on” view of the same cubes positioned as in “Setup” above, taken with a conventional lens. The forward cube appears larger, when in fact we know it to be exactly the same size.

The rightmost image below was made with a telecentric lens, which effectively collapses the Z dimension, while preserving X and Y. If measuring X and Y is your goal, without regard to Z, a telecentric lens may be what you need.

Courtesy Edmund Optics.

Depth of Field can be “pushed”

You are likely familiar with Depth of Field (DoF), the range in the Z dimension in which objects in the FoV are in focus. With a conventional lens, if an object moves out of focus, the induced blur is asymmetrical, due to parallax (aka. perspective error).

But with a telecentric lens, there is no parallax error, since the FoV is constant and non-angular. A benefit of this is that even if the target image is somewhat defocused with a telecentric lens, the image may still be perfectly usable.

In the two images below, the “sharp transition” edge is clearly optimal. But when measuring tolerances in a manufacturing environment, with mechanized conveyors, vibration, etc., target objects may not always be ideally positioned. So the “shallow transition” image from the object just out of focus is entirely acceptable to identify the center of mass for the circular object, since the transition is symmetrical at all positions.

Edmund Optics is widely recognized for their range of standard products – and their expertise in custom lens design when needed. The SilverTLTM and CobaltTLTM lens series each offer 10+ members, where all lenses are high-resolution and bi-telectric. Some additionally offer inline illumination options.

Noteworthy characteristics of both the SilverTL and CobaltTL series include:

  • Aperture controls often not available in competitor products
  • “Fast” ==> lower F# options than in many competitor products (so can work effectively with less light)
  • Conform to narrowly specified engineering tolerances
  • Pricing identical with or without in-line illumination via coax port

Edmund Optics SilverTLTM series

The SilverTL series pairs with C-mount sensors up to 7.5 MegaPixels, ideal with 2.8 µm pixel size. Magnification options range from 0.16X to 4X.

SilverTL series – Courtesy Edmund Optics

Edmund Optics CobaltTLTM series

For C-mount sensors up to 20 MegaPixels, and pixel size 2.2 µm, choose the CobaltTL series.

CobaltTL series – Courtesy Edmund Optics

What type of lens is best for my application?

Machine vision is a broad field, with a lot of variables across wavelengths, application goals, sensor, software, and lens choices. If you are a seasoned veteran, you may know from experience exactly what you need. Or you may want to review our on-line knowledge base or online blogs. Easier yet – just phone us at 978-474-0044. You’ll speak with one of our sales engineers, who put customer success first. Customers with successful outcomes – who return to us project after project – is our goal.

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 cards and industrial computers, we can provide a full vision solution!

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16, 20 and 24 MP: IDS uEye+ cameras with Sony Pregius sensors

IDS Imaging will soon release new members in their uEye+ camera series, utilizing Sony’s 4th generation Pregius S sensors. Included are 16, 20, and 24 MP offerings of the compact uEye+ USB3 cameras.

XLE+ housed and board-level options – Courtesy IDS Imaging

The “S” in Pregius S stands for “stacked”, a sensor architecture that is back-illuminated as well as layered, creating a light-sensitive, low-noise, high-performance sensor. Even the first 3 generations of Sony Pregius sensors broke new ground, but Pregius S is special. Read our dedicated blog on the Sony Pregius four generation offerings, including details on Pregius S.

Sony Pregius S sensorMPFormat
IMX 532 165328 x 3040
IMX 531 204512 x 4512
IMX 530 245328 x 4608
Sony Pregius S sensors joining IDS uEye+ family

IDS peak SDK : “Configuring instead of programming”

Enhancing the ease of development and deployment for the uEye+ cameras, IDS has released update 2.6 of “IDS peak”, the comprehensive software development kit (SDK), available at no cost. Of course the cameras are Vision Standard compatible ( U3V and GenICam), for those preferring third party SDKs, but IDS peak has much to offer IDS’ camera users.

While the SDK naturally includes conventional programming interfaces, IDS includes tools such as tools such as histograms, line and pixel views, color and greyscale conversions, useful automatic functions and bandwidth management. These skew deployment helpfully towards “configuring instead of programming”.

IDS peak is available for both Windows and Linux OS. In addition, IDS peak SDK works not just with IDS USB3 cameras, but also IDS GigE cameras. So multi-camera applications with mixed interfaces are possible. Or your developers can benefit from familiarity with a single SDK across multiple applications, bringing efficiencies to your team. Download IDS SDKs here.

Call us at 978-474-0044. Tell us about your applications goals and constraints, and we can guide you to any or all of cameras, lenses, lighting, software, and accessories.

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 cards and industrial computers, we can provide a full vision solution!

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4 generations of SONY Pregius sensors explained

Newer is better, right? Well yes if by better one wants the very highest performance. More below on that. But the predecessor generations are performant in their own right, and remain cost-effective and appropriate for many applications. We’re often get the question “What’s the difference?” – in this piece we summarize key differences among the 4 generations of SONY Pregius sensors.

In machine vision, sensors matter. Duh. As do lenses. And lighting. It’s all about creating contrast. And reducing noise. Each term linked above takes you to supporting pieces on those respective topics.

This piece is about the four generations of the SONY Pregius sensor. Why feature a particular sensor manufacturer’s products? Yes, there are other fine sensors on the market, and we write about those sometimes too. But SONY Pregius enjoys particularly wide adoption across a range of camera manufacturers. They’ve chosen to embed Pregius sensors in their cameras for a reason. Or a number of reasons really. Read on for details.

Machine Vision cameras continue to reap the benefits of the latest CMOS image sensor technology since Sony announced the discontinuation of CCD’s.  We have been testing and comparing various sensors over the years and frequently recommend Sony Pregius sensors when dynamic range and sensitivity is needed.

If you follow sensor evolution, even passively, you have probably also seen a ton of new image sensor names within the “Generations”.  But most users make a design-in sensor and camera choice, and then live happily with that choice for a few years. As we do when choosing a car, a TV, or a laptop. So unless you are constantly monitoring the sensor release pipeline, its hard to keep track of all of Sony’s part numbers. We will try to give you some insight into the progression of Sony’s Pregius image sensors used in industrial machine vision cameras.

How can I tell if it’s a Sony Pregius sensor?

Sony has prefixes of the image sensors which make it easy to identify the sensor family.  All Sony Pregius sensors have a prefix of “IMX.” Example: IMX174 – which today is one of the best sensors for dynamic range..

1stVision’s camera selector can be filtered by “Resolution” and you can scroll and see the sensors with a prefix of IMX.  CLICK HERE NOW

What are the differences in the “Generations” of Sony Pregius Image sensors?

Sony Pregius Generation 1:

Primarily consisted of a 2.4MP resolution sensor with 5.86um pixels BUT had a well depth (saturation capacity) of 30Ke- and still unique in this regard within the generations.   Sony also brought the new generations to the market with “slow” and “fast” versions of the sensors at two different price points.  In this case, the IMX174 and IMX249 were incorporated into industrial machine vision cameras providing two levels of performance.  Example being Dalsa Nano M1940 (52 fps)  using IMX174 vs Dalsa Nano M1920 (39 fps) using IMX249, but the IMX249 is 40% less in price.

Sony Pregius Generation 2:

Sony’s main goal with Gen 2 was to expand the portfolio of Pregius sensors which consists of VGA to 12 MP image sensors.  However, the pixel size decreased to 3.45um along with well depth to ~ 10Ke-, but noise also decreased!  The smaller pixels allowed smaller format lenses to be used saving overall system cost.   However this became more taxing on lens resolution being able to resolve the 3.45um pixels.  In general it offered a great family of image sensors and in turn an abundance of machine vision industrial cameras at lower cost than CCD’s with better performance.   

1stVision’s camera selector  can be filter by “Resolution” AND pixel size that correspond to one of the generations.  You will have a list of cameras in which you can select those starting with IMX.  I.e  All Generation 2 sensors will be 3.45um, and can narrow to a desired resolution. CLICK HERE NOW

Sony Pregius Generation 3:

For Gen 3, Sony took the best of both the Gen 1 and Gen 2.  The pixel size increased to 4.5um increasing the well depth to 25Ke-!  This generation has fast data rates, excellent dynamic range and low noise.  The family will ranges from from VGA to 7.1MP.  Gen 3 sensors started appearing in our machine vision camera lineup in 2018 and continued to be designed in to cameras for the last few years.

Sony Pregius Generation 4:

The 4th generation is denoted Pregius S, and is designed in to a range of cameras from 5 through 25 Megapixels. Like the prior generations, Pregius S provide global shutter for active pixel CMOS sensors using Sony Semiconductor’s low-noise structure.

New with Pregius S is a back-illuminated structure – this enables smaller sensor size as well as faster frame rates. The benefits of faster frame rates are self-evident. But why is smaller sensor size so important? If two sensors, with the same pixel count, and equivalent sensitivity, are different in size, the smaller one may be able to use a smaller lens – reducing overall system cost.

Surface- vs back-illuminated image sensors – courtesy SONY Semiconductor Solutions Corporation

Pregius S benefits:

With each Pregius S photodiode closer to the micro-lens, a wider incident angle is created. This admits more light. Which enhances sensitivity. At low incident angles, the Pregius S captures up to 4x as much light as Sony’s own highly-praised 2nd generation Pregius from just a few years ago!

With pixels only 2.74um square, one can achieve high resolution even is small cube-size cameras, continuing the evolution of more capacity and performance in less space.

Courtesy Sony Sensors

Fun fact: The “S” in Pregius S is for stacked, the layered architecture of the sensor with the photodiode on top and circuits below, which as note has performance benefits. It’s such an innovation – despite already high-performing Gens 1, 2, and 3, that Sony graced Gen 4 as the Pregius S to really call out the benefits.

Summary

While Pregius S sensors are very compelling, the prior generation Pregius sensors remain and excellent choice for many applications. It comes down to performance requirements and cost, to achieve the optimal solution for any given application.

Pregius sensors by generation and sizes – Courtesy Sony Sensors

Many Pregius sensors, including Pregius S, can be found in industrial cameras offered by 1stVision. Use our camera selector to find Pregious sensors, any staring with “IMX”. For Pregius S in particular, supplement that prefix with a “5”, i.e. “IMX5”, to find Pregious S sensor like IMX540, IMX541, …, IMX548.

Contact us

Sony Pregius image sensor Comparison Chart

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 cards and industrial computers, we can provide a full vision solution!

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3D IDS Ensenso C (Color) Series

Sometimes just the Z-values are enough, no image needed at all. Some applications require pseudo-images generated from a point cloud – whether in monochrome or with color tones mapped to Z values. Yet other applications require – or benefit from – 3D digital point cloud data as well as color rendering. IDS Ensenso’s C Series provides stereo 3D imaging with precise metrics as well as true color rendering.

Two models of Ensenso stereo cameras – Images courtesy of IDS

If you want an overview of 3D machine vision techniques, download our Tech Brief. It surveys laser triangulation, structured light, Time of Flight (ToF), and stereo vision. If you know you want stereo vision, you might like an overview of all IDS Ensenso 3D offerings.

But if you know you want stereo 3D accuracy to 0.1mm, with color rendering, let’s dive in to the IDS Ensenso C Series. If you prefer to speak with us instead of reading further, just call us at 978-474-0044, or request that we follow up via our contact form.

Key differentiator is “projected texture”

In the short video below, we see 3 scene pairs. For each pair, the leftmost images are the unenhanced 3D image. The rightmost images take advantage of the projected texture created by the LED projector and the RGB sensor, augmenting the 3D point cloud with color information. It can be a differentiator for certain applications.

Video courtesy of IDS

Application areas

Let’s start with candidate application areas, from customer perspective, before pointing out specific features. In particular let’s look at application areas including:

  • Detect and recognize
  • Bin picking
  • De-palletizing
  • Test and measure

Detect and recognize

The ability to accurately detect moving objects to select, sort, verify, steer, or count can enhance (or create new) applications. Ensenso C’s high-luminance projector enables high pattern contrast for single-shot images. Video courtesy of IDS.

Bin picking

Regardless of a robot’s gripping sensitivity, speed, and range of motion, 3D imaging accuracy is central to success. Ensenso C’s integrated RGB sensor can make all the difference for color-dependent applications. Video courtesy of IDS.

De-palletize

De-palletizing might seem like a straightforward operation, but must detect object size, rotation and position even with different and densely stacked goods. Ensenso C supports all those requirements – even from a distance. Video courtesy of IDS.

Test and measure

Automated inspection and measurement of large-volume objects are key for many quality control applications. Precision to the millimeter range can be achieved with Ensenso C at working distances even to 5m. Video courtesy of IDS.

IDS Ensenso C Series

With two models to choose from, Ensenso C supports a range of working distances and focal distances – see specifications.

Both models utilize GigE Vision interface; both embed a 200W LED projector; both use C-mount lenses; both provide IP 65/67 protection. And both models are easy to configure with the Ensenso SDK: Windows or Linux; sample programs including source code; live composition of 3D point clouds from multiple viewing angles; robot eye-hand calibration; and more.

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!