Webinars
We invite you to watch our series of technical Webinars below or on the Sunex YouTube Channel; please contact us if you have any questions or want to suggest a topic you are interested in.
How are lens elements made ?
Digital imaging lenses are often made of multiple lens elements to achieve the required specifications. How are those lens elements made in mass production ? The answer to this question depends on the type of element chosen by the lens design engineer. Three types of lens elements are commonly used today. They are polished glass elements, molded plastic elements and molded glass elements. Each type of elements has its own unique process steps and capabilities. …
Basic Thread Considerations for Lens/Holder Pairing on Board-Mount Cameras
At Sunex, we get many questions about lens and mount (holder) threads when it comes to board-mount lenses. In this post, we will explore some of the basic considerations of threaded lens and mount combinations, as opposed to some other common methods, which we will touch on. Although this post will not be a detailed tutorial of the mechanical engineering theory of thread specifications, a basic understanding of thread spec and tolerance helps to understand…
An Optics Platform for Automotive Vision
New technologies, new application requirements, and new market segments are challenging every automotive vision program to consider and balance performance vs. cost, glass vs. hybrid, and off-the-shelf vs. custom design. Taking a platform approach at the lens component level can deliver quality optics in support of faster innovation cycles, increased manufacturability, and optimized lifetime cost and reliability at the system level.Before we answer, how Sunex arrived at the concept of an Automotive Digital Imaging Optics…
Relative magnification and aspect ratio
It is well-known that the magnification of an imaging lens changes with the object distance (distance from the object to the lens). However it is less known that the magnification changes with the field angle as well (i.e, where in the field the object is placed). Additionally the off-axis magnification can be asymmetric. In other words, the tangential and sagittal magnifications can be different. This causes shape deformation for off-axis objects. For example, a golf…
Hydrophobic and Oleophobic Coatings
Applications in Imaging Optics Oleophobic refers to the physical property of a molecule that repels oil. Fluorocarbons are deposited to the substrate to create a monolayer that repels oil and water. The additional benefit of evaporative oleophobic treatments is also hydrophobicity or inherent water shedding capabilities. This inherent benefit is true of all evaporative oleophobic treatments, but not necessarily inherent in all hydrophobic treatments. The key differentiator between oleophobic and hydrophobic treatments is measured through…
Sunex Part Number Tutorial
Sunex has many online tools designed to help you find a lens according to your specifications that is best suited to your application. Once a lens is identified based on first order parameters, there can be many options or variants of that part number (PN). It is therefore useful to know how to interpret Sunex part numbers and the PN itself can provide insight into the lens’ performance or intended use. The intention of this…
The Art of Making an HDR Lens
New imagers can capture light intensity variations up to six or more orders of magnitude within the same image frame (+120db HDR, 20*LOG(1e6)), and together with the growing number of applications using computer vision, they are putting very demanding requirements on lens performance. Designing and manufacturing an HDR lens is probably as much art as it is science and engineering. Sunex HDR Optimized™ lenses are the first stepping stone to build a system, that performs…
Finite Imaging; When Focusing to Infinity Doesn’t Cut it.
Many applications require that CMOS or CCD imaging lenses be optimized for a finite object, that is, for an object distance closer than “infinity.” The practical definition of infinity varies based on individual use-case requirements and specific lens being used. It can be defined in different ways, such as spot size, through-focus MTF, etc. As a general rule of thumb, and depending on F/#, infinity is generally 100-200x the focal length (EFL) of the lens…
Cleaning Procedure for Optics
The general guideline for cleaning optics is “if it’s not dirty, don’t clean it”. Handling optics increases their chances of getting dirty or damaged, so you should clean optics only when necessary. Both the proper cleaning products and proper methods are equally important to cleaning the optic. There are different methods for cleaning and certain specialized optics require particular attention and change in procedures. Below are general guidelines to be used as a reference only…
Lens Customization- What You Need to Know
One of the questions we frequently get at Sunex is some variation of, “Can I modify a standard lens, and what does this entail?” The answer to this question is, “Yes!” depending on what you would like to modify, of course! In general, there are four categories of what can potentially be modified on a standard lens: External Mechanical Features Coatings/Filters F/# Specifications While first-order lens parameters which are inherent to the optical design typically…
Boresight Stabilization™
A typical lens assembly consists of several lens elements inside a cylindrical barrel. Due to the mechanical clearance requirement, the internal element diameters must be smaller than the barrel internal diameter. This creates potential risks that could result in boresight errors or changes: Lens to lens variance of the optical axis due to manufacturing tolerance A possible lateral shift of individual elements overtime due to strenuous conditions The first potential risk (lens to lens variance)…
Lens mapping function and distortion
Lens distortion is a commonly used term in the general specification of lenses. The classic, textbook definition of distortion includes barrel and pincushion type distortions. These concepts are useful for photographic optics where the field of view of the lenses are not extreme. Lenses designed for machine or computer vision applications can have extreme field of views. Field of view greater than 100 degrees are common specifications for machine vision lenses. We need to develop…
The Advantages and Disadvantages of Stopping Down a Lens
One modification that is commonly requested by our Customers is changing the F/# of a standard lens. The most common reason to stop down a lens is to resolve more detail and gain greater depth of field in an image. However, the term itself can sometimes be confusing, and there are limits to how much you can stop down a lens before encountering diminishing returns. “Stopping down a lens” refers to increasing the numerical f-stop…
Tailored Distortion®: Distortion Correction at the Speed of Light
Super wide-angle lenses and fisheye lenses have pronounced barrel distortion. When viewing a flat object, off-axis features are “squeezed” significantly relative to the on-axis ones. This reduces the effective off-axis resolutions. For many applications, it is an undesirable effect. It is possible to post-processing the image to reduce this effect. However, post-processing in software reduces the image quality because the missing off-axis information must now be interpolated. We created a new class of super wide-angle…
When Does a Hyperspectral, or “Day-Night” Lens Make Sense?
Certain applications require a broad spectral operating range and customers oftentimes inquire whether a lens can perform “well” out to their wavelength of interest. These requests typically involve both visible (VIS) and near infrared (NIR) wavelengths. For purposes of this discussion, a wavelength range roughly from 470nm (or lower) out to about 850-950nm is assumed. Fundamentally, it is important to consider the use-case of the lens and determine how the VIS and NIR wavelengths apply…
Automotive Camera Trends Driving Changes in Optical Designs
The imaging applications in the automotive industry go through rapid changes. Where just a couple of years ago a lens/camera just needed to survive, the expectations moved to better performance, consistent and reliable over a wide temperature range. Below is a video of the talk Sunex presented at the AutoSens 2017 show, sharing experiences and observations on how requirement changes on the camera level impact consideration and design approaches on the lens level. Some of…
“Scaling” as a lens design tool
“Scaling’ refers to a method where a known lens design is proportionally enlarged or reduced geometrically to meet a different image size requirement from what the lens was originally designed for. For example, say, we have a lens that was originally designed for a 1/3” format sensor with an image circle of 6mm, we can “scale” up that design to make the image circle 8mm. This new scaled-up design is now capable of supporting a…
Why is lens design so hard?
With the advent of computers and more processing power, the art of lens design has matured. But computers cannot solve the whole problem. A computer can select a configuration and designer optimizes that configuration. Can a machine learning algorithm find the absolute best lens design? Yes, if you try an infinite number of different design form. But..”I still want to be young when we get there!” Hence, the journey of developing an elegant design will…
What is Active Alignment?
One of the most common questions Sunex receives is regarding the need for Active Alignment of lens modules. Initially, customers designing or prototyping an imaging system may find it hard to see the value of actively aligned modules. After all, active alignment requires a significant tooling investment. In addition, during the prototyping phase, customers can typically achieve great results in small numbers by manually focusing the lens and gluing it into an off-the-shelf camera module….
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