The resale value of a used smartphone is highly dependent on the quality of the screen. In this project, we demonstrate methods to automatically identify screen scratches and determine screen quality using a custom imaging and illumination layout and computer...
John
Bidirectional Scattering Distribution Function
by John | Uncategorized
As optical engineers, we are in charge of more than just the design and implementation of optical systems for specific applications: we often need to evaluate optical systems’ performance or to assess the quality of optical components. To do these assessments, we...
How does a light pipe overmold work?
by John | illumination, illumination lens design, LED
Simple method to generate a light-pipe from a keyboard overmold
Moving from RasberryPi image processing to an MCU
by John | machine vision
We’ve built a number of image processing systems that use Raspberry Pi and other single board computers together with OpenCV and other Python libraries such as Scikit image and Dlib. For example, take a look at this defect inspection system This works well for...
How to read an MTF chart
by John | optical engineering
Understanding the purpose of an MTF chart and how to read and MTF chart is an essential skill for anyone involved in the development of products that use optics.For most applications an MTF test is the single best method to determine lens quality. In this post we will...
Understanding Strehl ratio & wavefront error for optical systems
by John | optics definitions
A Strehl ratio is used to define the quality of an optical system by showing how a real optical system compares to an ideal aberration-free system. The Strehl ratio incorporates the Point Spread Function (PSF) and its relation to wavefront aberration of the optical...
Laser beam homogenization: 2 methods explained
by John | optical engineering
Types of Laser Beam Homogenizers There are two widely used methods of laser beam homogenization for systems where uniform beam profiles are needed: homogenization using a lens array optic and homogenization using a light pipe rod. Each method has its own advantages...
What is a rayset (rayfile) ?
by John | illumination lens design
A rayset (sometimes called a rayfile) is a key element in the design of any illumination system. It describes the path of hundreds of thousands, millions, and even billions of rays of light as they leave a source (typically an LED). This data set is used in a ray...
Is higher sensor resolution always better?
by John | optical design, resolution
An optical system is only as strong as its weakest link. When designing an imaging system, sensor resolution is just one important factor and it is important to ensure sensors and detectors are well matched. Take these scenarios: Taking a selfie with your cockadoodle...
Designing a custom spectrometer
by John | spectrometers
We will delve in more detail here on the types of questions we ask our customers when starting a spectrometer design program and the various stages of development. Some recent spectrophotometer development tasks included: Miniaturize a current lab prototype Automate...
Free multi-catalog lens search tool launched
by John | optical engineering, optics
Last week, we announced the launch of a free lens search tool for optical engineers. It is available at www.opticsforhire.com/lens-search The searchable database allows engineers working in robotics, machine vision, industrial, and security industries...
Launching a custom spectrophotometer design
by John | optical engineering
Spectrophotometers are an essential analytical tool used in many disciplines including biology research, chemical and clinical labs, medical imaging and biomarker testing. They are used to detect, identify, and quantify matters in solution, including DNA,...
4 Essential Opto-mechanical Design examples
by John | lens design, opto-mechanical design
Opto mechanical design overview and definitions Opto mechanical design is an engineering specialty related to the positioning of optical elements such as lenses, filters, beamsplitters, reflectors, and diffractive elements in mechanical structures that will...
TIR Lenses, 3 basic design concepts
by John | FAQ, illumination
Working principle of TIR lenses: A TIR lens works on the principle of total internal reflection. When light reaches an interface between two materials with different refractive indices and the correct angle of incidence, there is refraction (bending of a light ray...
Steps for correcting chromatic aberrations in lens design
by John | optical design
In many applications of lens design, avoiding chromatic aberrations is a key performance requirement. In this video, we review some of the causes of chromatic aberrations and methods to correct them. •All optical media have dispersion, meaning the index of...
Understanding image depth of field
by John | optics definitions
Depth of field is a distance range where the image optical resolution is as high as possible for that lens, i.e. an image appears to be in focus. When starting a lens design program, having a good understanding of this parameter’s physics will help you and your...
What are a ‘typical’ steps in lens design ?
by John | lens design, optical design
Overview OFH works on many different types of projects, each with its unique goals and deliverables. For illustration, here is a breakdown of a lens design project from 2012. Our client produced a very low cost diagnostic microscope to view saliva with 30x...
Can your lens vendor test your lens?
by John | lens design
Selecting the right lens manufacturing vendor is a multi step process. To start, you will need detailed production drawings to ensure the vendor understands what you require and the tolerances involved.. As you get quotes, you may find qualified suppliers with good...
Hiring a lens designer
by John | lens design consulting
Planning to hire a lens design partner to assist with your optical engineering program? Here are a few things to consider. Do you need a lens for illumination or for imaging? The design methods and software tools used for illumination and imaging are different. Many...
Object tracking with OpenMV
by John | machine vision
We’ve been experimenting recently with our OpenMV camera and tools. In this video, you can see a simple system to track objects. Building this cost just $80 for the camera and a few hours’ time of coding and testing. In addition to a cellphone backlight , we were able...