1stVision, Author at 1stVision Inc. - Machine Vision Articles

March 13, 2026March 13, 2026

Varifocal lenses: What are they and how do they differ from a Zoom lens?

In machine vision, historically there is a preponderance of fixed focal length (FFL) lenses, also know optically as a prime lens. They are less complex to design and manufacture, and are high-performance in terms of image sharpness and ability to accept wide aperture options for low-light applications. FFL lenses are typically are set for a designed FOV and WD and don’t have flexibility on focal lengths. If your application is like that, lucky you.

But my application isn’t like that!

You may have a factory production monitory project, for example. You know the general dimensions of the layout and the approximate camera mounting position. But you have limited time to configure and deliver proof of concept or acceptance testing. so you want to show up with everything you need to achieve good outcomes, instead of guessing wrong on a fixed focal length lens and having to exchange it.

Whatever your planned application, you know the optical “neighborhood” but need the flexibility to fine-tune in the field.

Zoom lens

A zoom lens remains in focus across a range of focal lengths, and is often remotely controlled. Likewise it’s also often motorized. So they tend to be large(ish), heavier, more complex to design, and are more expensive than a fixed-focal length lens.

In the illustration above, notice how the light rays entering from the right range from a wide field of view (FOV) at the top to a narrow FOV at the bottom. That’s a consequence of the changing focal length. It’s an asset if you need that behavior. Or a liability if you don’t

This blog is about varifocal lenses, so that’s all we’ll say about zoom lenses here. But the “different focal lengths” and “different FOV” concepts also apply to varifocal lenses, so it’s worth noting points of overlap.

Varifocal lens

A varifocal lens is designed to hit the sweet spot between fixed focal length vs. zoom. By spanning a (modest) range of focal lengths, a varifocal lens can be adapted in the field to optimize for observed conditions.

You might not know at design time exactly what final focal length you’ll choose, so a range of coverage lets you tune as you deploy and run acceptance tests. It also means the same lens could be used for a year or more in one setting – then loosen a set screw, refocus, and tighten the set screw and the same lens performs great in the new context.

Example: per red ellipses markup, this lens offers focal lengths from 4.4 – 11mm – Courtesy Kowa

But unlike a big motorized zoom, the varifocal lens is often* manually adjusted. And it’s typically modest in size, weight, design complexity, and cost.

(*) EXCEPTION! The Optotune electrically tunable series describe below uses liquid lens technology for autofocus within milliseconds.

Enough concept already – what varifocal lenses are available?

Below we present and link to three different varifocal product lines carried by 1stVision. We sequence by alphabetical order, but each series has its own value proposition, depending on your application needs:

Kowa LMVZ Varifocal Lenses

Kowa’s LMVZ varifocal lenses are designed for machine vision, industrial inspection, and surveillance applications. Their adjustable focal length design allows integrators to fine-tune field of view without changing lenses.

Kowa varifocal machine vision lens — Kowa LMVZ varifocal lenses – optionally with IR correction for VIS + SWIR – Courtesy Kowa

Optotune Focus Tunable Lenses

Optotune is an industry leader in focus tunable lenses. Many are electrically tunable, utilizing liquid lens technology. They also offer a manually tunable lens.

Optotune tunable lenses — A focus tunable lens
– Courtesy Optotune

Unlike manually tunable varifocals, the EL series offers fast, precise autofocus in milliseconds with no moving mechanics.

Tamron Vari-Focal Lens Series

The Tamron vari-focal series is designed for high-resolution IP and security surveillance cameras. These lenses offer flexible focal length adjustment for both wide-area coverage and detailed zoom.

Tamron varifocal machine vision lens series — Mega Pixel varifocal lens series – Courtesy Tamron

Select IR-corrected models enable true day/night performance, while compact, durable construction ensures dependable operation in commercial, industrial, and municipal security installations.

Optics is partly physics and science…

But it’s also engineering, and performance requirements, and budget, and experiential knowledge. If you’ve got a lot of all that in your wheelhouse, just call for a quote at 978-474-0044. Or if you’d like some help in choosing, call that same number and tell us a little about your application. Either way, we’re here for you. For lenses, cameras, 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 cameras, lenses, cables, NIC cards and industrial computers, we can provide a full vision solution!

About you: We want to hear from you! We’ve built our brand on our know-how and like to educate the marketplace on imaging technology topics… What would you like to hear about?… Drop a line to info@1stvision.com with what topics you’d like to know more about.

#varifocalmachinevisionlens

#zoommachinevisionlens

#optotune

#kowa

#tamron

March 13, 2026March 13, 2026

IDS uEye EVS Event Based Cameras – Use cases

We introduced these event-based cameras in a previous blog – still a great entry point and overview. In this new blog we’ll highlight use cases. They are pretty compelling.

But first we re-run a single graphic to highlight the paradigm shift from frame-based to event-based imaging:

frame-based vs event-based paradigm — XCP-E Event based cameras utilize the Sony Prophesee sensor – Courtesy IDS Imaging

If you come from a frame-based imaging background – as most of us do – it’s worth getting one’s head wrapped around the event based model. It’s that different – at the technology level and in what it enables at the applications level.

On to use cases and key takeaways…

Results instead of raw data: Per the scene-driven remark in the paradigm comparison graphic above, observe the video analysis clip below. By ONLY picking up on motion, the camera delivers exactly and only what one wants – the people and suitcases passing through the field of view.

Results instead of raw data – Courtesy IDS Imaging

A frame-based approach to such an application would require complex algorithms to identify the “moving stuff” from the “background stuff”, which is compute intensive. It may be doable the hard way, but it takes effort – and isn’t as performant.

Extremely high dynamic range

See in the dark. The Sony Prophesee IMX636 sensor recognizes contrast changes even from 0.08 lux.

Sensitive in very low light – Courtesy IDS Imaging

Detect extremely fast processes

Temporal resolution <100us. i.e. the minimum measurable time difference between two consecutive pixel events, is less than 100µs. That’s comparable to a traditional image-based frame rate of more than 10,000 FPS without motion blur.

High speed applications – Courtesy IDS Imaging

blah blah

Efficient data processing

Only changes are captured – static areas are ignored. So there is (much) less data to process than with a frame-based approach. This saves memory, data transfer volumes, and compute time.

The astute reader will have already inferred that this is a corollary on the “results instead of raw data” message and video earlier in this blog. It’s such a key point it bears repeating.

Less data generated means less data to process – Courtesy IDS Imaging

The following short video shows that the Sony Prophesee IMX636 is the key to sending less data, as it only senses “what’s changed”. Essentially it lights up a pixel exactly and only when that position senses motion – and not when it doesn’t.

Frame-based approach sends entire frame every time vs. event-based just sends each next change – Courtesy IDS Imaging

Use cases

Some of the videos above suggest certain use cases, but let’s spell out a few:

Monitoring: Compared to CCTV, the IDS uEye XCP-E cameras are more compact, and only show action as opposed to (also) steady-state. Or combine the two with event-based cameras logging the timestamps of interest.

Video analysis and Smart City people tracking: A level up from simple monitoring, people tracking doesn’t just detect motion but infers/projects trajectories, and may lead or assist in threat detection.

Drone detection: Just as with people tracking, an event-based camera finds what’s moving against a field of static clutter, as it only sees what’s moving.

Gesture recognition: UI design opportunities, whether for pupil tracking, head motions, and/or hand/finger tracking.

Industrial applications: Monitor equipment vibration to optimize preventative maintenance and/or anticipate and avoid catastrophic breakdown.

Counting: E.g. pill production and sorting, food processing, or other fast-but-small-items conveyor applications.

Takeaway: If it moves, an event-based camera will find it.

See the entire family of IDS uEye XCP-E cameras. Call us at 978-474-0044. Tell us a little about your application and we’ll help you pick the ideal camera and accessories.

#IDS #uEye #EventBased

February 4, 2026February 4, 2026

XTIUM3 PCIe Gen4 frame grabber for ultra-fast image acquisition

Frame grabbers interface between high-speed cameras and PCs to reliably transfer and buffer image data. They can also do various pre-processing and image transformations, improving throughput and reducing workload on the PC.

Teledyne DALSA is a recognized industry leader in frame grabbers and machine vision cameras. Their board-level frame grabbers are dependable and high-performance. Now there’s Teledyne DALSA’s XTIUM3-CLHS PX8 Camera Link HS Frame Grabber. It’s designed for maximum sustained throughput with high-speed image acquisition rates up to 8.6 GB/s and host transfer rates up to 12.5 GB/s.

Teledyne DALSA XTIUM3-CLHS PX8 Gen4 frame grabber PCIe for high speed vision systems

High speed data transmission

Using CLHS X-protocol, Xtium3-CLHS PX8 achieves over 97% packet efficiency with 64/66-bit encoding. With 7-lane AOC cables, maximum input data rates at cable lengths beyond 30m. Data forwarding enables real-time redistribution of data to up to 12 computers, connecting with other Xtium3-CLHS grabbers via standard AOC cables. Image courtesy Teledyne DALSA.

Optimized performance and compatibility

The Xtium3 series leverages PCIe Gen4 architecture to deliver sustained throughput of 13.2 GB/s directly to host memory, minimizing CPU overhead and accelerating image processing. Its enhanced memory design supports area and line scan, monochrome and color cameras, and offers exceptional performance for Camera Link HS® and CoaXPress® interfaces.

Faster. More efficient. Higher-performance.

Thanks to Moore’s law and industry innovation, machine vision practitioners benefit from electronics components such as cameras, frame grabbers, and computers that outperform their predecessors. If you already use CLHS and prior generation frame grabbers, you may already know you need or want the XTIUM3-CLHS PX8.

Or are you at the design and brainstorming phase?

We’re always happy to provide a product quote, whether for single units or for multiples, of course. But we take pride in assisting our customers by guiding component selection across camera interfaces, sensor selection, lenses, frame grabbers, and more. Call us at 978-474-0044.

XTIUM3 family – more to follow

The XTIUM3 – CLHS PX8 is the first member of the XTIUM3 family, continuing Teledyne DALSA’s commitment to high-performance frame grabber innovation.

XTIUM3 - CLHS PX8 is the first member of the XTIUM3 family, continuing Teledyne DALSA's commitment to high-performance frame grabber innovation — Xtium3 overview – Courtesy Teledyne DALSA

January 28, 2026February 2, 2026

Dynamic Operating Point Optimization – Explained!

Short Wave Infrared (SWIR) imaging is enjoying double-digit growth rates, thanks to improving technologies and performance, and innovative applications. Unlike visible-light sensors, SWIR cameras can image through silicon, plastics, and other semitransparent materials. That’s really effective for many quality control applications, materials sorting and inspection, crop management, fruit sorting, medical applications, and more.

*Visible vs. SWIR image pairs – Courtesy Allied Vision – a TKH Vision brand*

Unlike CMOS sensors, from which high-quality images are reliably derived under wide operating conditions, SWIR sensors typically need “tuning” relative to temperature and exposure duration. First generation SWIR cameras sometimes generated images that while useful, were a bit rough and with certain limitations in the extreme. SWIR camera manufacturers have been innovating solutions to raise the performance of their cameras.

What’s the problem?

In short-wave infrared (SWIR) imaging applications, camera operation points such as exposure time, gain and bit-depth need to be adapted depending on the inspection task at hand. Image sensor defects such as defective pixels and image non-uniformities – inherent to SWIR sensors – are sensitive to the aforementioned operations points.

Unless controlled, image quality can suffer

Consider the following image:

The gray field is intentionally unexciting as a flat field baseline without a target. The white dots are undesired defect pixels, an unfortunate characteristic that one can thankfully correct through interpolation. This image is meant to show “what we do NOT want”.

The four parameters exposure setting, temperature, bit-depth, and gain may collectively be called the “Operating Point” of a SWIR sensor, as together they have a significant bearing on image quality. Through manual or automated adjustments, one can optimize image outcomes.

Harnessing variable parameters into manageable corrections – Courtesy Allied Vision – a TKH Vision brand

In this blog, we provide context for these concepts. And we introduce Dynamic Operating Point Optimization (DOPO) as an automated innovation available in the fx series of SWIR cameras offered by SVS Vistek / Allied Vision.

fx series SWIR cameras – Courtesy SVS Vistek / Allied Vision – a TKH Vision brand

Before Dynamic Operating Point Optimization (DOPO)

SWIR cameras with some image correction capabilities – prior to DOPO we’ll describe in the next section – certainly improved image quality. Largely via defect pixel correction (DPC) and non-uniformity correction (NUC).

Defect pixel correction (DPC) is achieved by replacing the “hot” or “dead” pixel value by the average value of its nearest neighbors. As long as there isn’t a cluster defect with multiple adjacent defect pixels (typically identified and rejected at manufacturing quality control), this is an effective solution.

Non-uniformity correction (NUC) is a bit more complex, but worth understanding. The non-uniformities arise in thermal imaging due to variations in sensitivity among pixels. If uncorrected, the target image could be negatively impacted with striations, ghost images, flecks, etc.

Factory configuration of each camera, before finalizing testing and shipping, adapts for the nuanced differences among individual sensors. Correction tables are created and stored onboard the camera, so that the user receives a camera that already compensates for the variations.

In reality it’s a bit more complicated

In fact defect pixels aren’t always simply hot or dead: they may appear only at certain operating points (exposure duration, temperature, gain, bit-depth, or combinations thereof).

Likewise for non-uniformity characteristics.

So that factory configuration mentioned above, while satisfactory for many applications, is a one size fits all best hope compromise, relative to the tools (then) available to the camera manufacturer and the price point the market would accept. Just as with t-shirts and socks, one size doesn’t really fit every need.

Dynamic Operating Point Optimization (DOPO)

Allied Vision has introduced dynamic operating point optimization (DOPO) to further automate SWIR cameras’ capacity to adapt to changes brought about by exposure time, temperature, gain, and bit depth. Let’s examine the graphic below to understand DOPO and the added value it delivers.

First consider the Y-axis, “Image Quality”. Looking at the flat-field gray block, clearly one would prefer the artifact-free characteristics of the upper region.

Also note the X-axis, “Sensor Temperature / Exposure Time”, for an uncooled thermal sensor. (Note that some thermal cameras do have sensor cooling options, but that’s a topic for another blog.) See the black line “No correction” sloping from upper left to lower right, and how the number of image artifacts grows markedly with exposure time. Without correction the defect pixels and sensor non-uniformities are very apparent.

Flat-field image quality with and without corrections – Courtesy Allied Vision – a TKH Vision brand

Now look at the gray lines labeled “NUC+DPC”. For a factory calibrated camera optimized for a sensor at 30 degrees Celsius and a 25ms exposure, the NUC and DPC corrections indeed optimize the image effectively – right at that particular operating point. And it’s “not bad” for exposure times of 20ms or 15ms to the left, or 30ms or 35ms to the right. But the corrections are less effective the further one gets away from that calibration point.

Finally let’s look at the zig-zag red lines labeled “DOPO”. Instead of the “one size best-guess” factory calibration, represented by the grey lines, a DOPO equipped camera is factory calibrated at up to 600 correction maps, varying each of exposure time, temperature, gain and bit depth across a range of steps, and building maps that represent all the stepwise permutations.

Takeaway: DOPO provides a set of correction tables not just one

So with DOPO providing a set of correction tables, the camera can automatically apply the best-fit correction for whatever operating point is in use. That’s the key point of DOPO. Unlike single-fit correction tables, with so many calibrated corrections under DOPO, the best-fit isn’t far off.

Thermal imaging with SWIR cameras – plenty of choices

There are a number of options as one selects a SWIR camera. Is your choice driven mostly by performance under extreme conditions? Size? Cost? A combination of these?

Call us at 978-474-0044. We can guide you to a best-fit solution, according to your requirements.

We might recommend a DOPO equipped camera, such as one of the fxo series SWIR cameras:

DOPO equipped SWIR cameras – Courtesy SVS Vistek / Allied Vision – a TKH Vision brand

Or you might be best-served with a Goldeye camera, in cooled or uncooled models:

Goldeye available in uncooled and cooled models – Courtesy Allied Vision – a TKH Vision brand

Or an Alvium compact camera, whether housed or modular (for embedded designs), in USB / MIPI CSI-2 or GigE interfaces.

Alvium cameras – Courtesy Allied Vision – a TKH Vision brand

The key message of this blog is to introduce Dynamic Operating Point Optimization – DOPO – as a set of factory calibration tables and the camera’s ability to switch amongst them. An equally important takeaway is that you may or may not need DOPO for a particular thermal imaging application. There are many SWIR options, in cameras and lenses, and we can help you choose.