Light pollution
By Katharina Zeuner| When light ends up where it doesn’t belong Living in Stockholm has its perks – one of them is having a ski slope within walking distance. It’s so close that I can see it from our living room. In the evenings, the floodlights illuminating the slopes are glaringly visible from our dinner […]
ADAS Optics – Not Just LiDAR
By Olov von Hofsten|I have previously written some articles about LiDAR. This is what I have worked with the most and it is an interesting technology. But ADAS (Advanced Driver Assistance Systems) is not just LiDAR. Actually, LiDAR has not yet had the impact on ADAS as I thought before (although I still think it […]
The Myth of the 10 000 Lux Lamp
December in Stockholm and the sun rises at 8.30 and sets at 14.30, which makes many of us wonder, “why am I living here” or start looking for southern vacation destinations. It also leads to several articles in the newspapers about hacks on how to avoid winter depression or just get less tired. Artificial lighting […]
Everything you wanted to know about Metaoptics but were too afraid to ask
By Olov von Hofsten | Metaoptics brings something truly new and innovative to optics. The possibility to exchange a large number of lenses into a thin, flat surface sounds almost too good to be true. Metaoptics has been around for a while now, and we now see many applications introduced by Samsung, Google, ST, and […]
Speckles and their likelihood of detection
By Olov von Hofsten| Speckles are something that I have always been fascinated by. When I saw them for the first time, during school, they didn’t look like anything I had ever seen before. The pattern of bright dots moves with your position as if they are floating in space and you cannot focus on […]
LiDAR Link Budget
By Olov von Hofsten| One of the most important specifications of a LiDAR is the range. How far can the LiDAR see? This may be the first question one asks. You quickly realize that this depends on a multitude of extrinsic and intrinsic parameters. For the extrinsic parameters, target reflectivity and sunlight illuminance are the [&hell
Using the EMVA1288 standard
By Linus Frantzich | Comparing the performance of two image sensors can almost be an administrative, rather than a technical task. Most image sensor metrics depend on exposure time, gain, lens performance and temperature to name a few. Including all conditions and comparing using the same conditions exponentially increases the adminis
The Optics Of Rainbows
By Gustav Strömqvist | Rainbows are a beautiful physical phenomenon, forming as the result of how the sunlight refracts and reflects inside droplets of water before reaching your eyes. In the visible range, water has a refractive index of n ≈ 1.33 or n ≈ 4/3, with a difference of around 0.0013, or 1%, between violet (400
Lightguides – shape and performance – part 2
By Billy Kaldvee | In the last post we recommended to keep the distance between the LED and the light guide ten times smaller than the light guide diameter. To demonstrate why this is recommended for a high efficiency system, we once again do simulations on the 3 mm diameter circular light guide with the […]
Lightguides – shape and performance – part 1
By Billy Kaldvee | Have you ever done a mechanical design of a light guide without doing any optical simulations and wondered why the result looked as something you did not expect? In two posts we go through some of the basic aspects of light guide geometries and how they influence the perceived output. In […]
Etendue and Optical Invariants
By Olov von Hofsten and Simon Olin | “The possibilities of optics are endless” – you may have heard things like this and it sounds great and wonderful. Unfortunately it is not true – you have been told a lie. The possibilities of optics are NOT endless. In fact, it is very important to know […]
The Perfect LiDAR – does it exist?
By Olov von Hofsten | As a consultant, I have often been approached by unrealistic requirements from customers, and the LiDAR business is particularly prone to this. Perhaps because the technology is new. A customer often wants: If a customer was to write a specification for a camera system, this would not happen, as there […]
Understanding Camera Sharpness: The relationship between pixel count and resolution in smartphone cameras
By Jan Lüttgens | In a previous post, we explained how sharpness and resolution are two separate characteristics of a camera system. Yet, from a consumer perspective they may seem to be somewhat correlated, as lens and image sensor resolution are matched and combined with a finely tuned image processing pipeline to yield optimal perf
LiDAR Detection Techniques
Since LiDAR has been around for quite some time, I have heard a lot of different names of various detection methods. In practice there are not as many methods of detecting signal as there are names for them so in this post, I will try to sort this out. When it comes to signal transmitting, […]
Simulating Luminance in Zemax
By Olov von Hofsten | Luminance is arguably the most important component to analyze when evaluating a lighting design since it answer the fundamental question, “What will it look like?”. In Zemax you get easily get the luminance for an entire surface, but not the local luminance or luminace maps. However, there are ways around [&h
Setting up a camera lab
By Henrik Eliasson | Measuring the image quality of a camera is no small task. If you are setting up a lab for this purpose, there are quite a few considerations to take into account and expensive equipment to buy. You need to think about the room for the lab itself, its size and layout. […]
Sharpness and resolution, part II
By Henrik Eliasson | In the previous post we looked at the relation between optical resolution and sharpness. We could see that there is no clear correlation between the two. In this post we will complicate things a little by including the pixel resolution (we therefore assume a digital camera) into the mix. The last […]
Sharpness and resolution, part I
By Henrik Eliasson | Sharpness is one of the most important image quality attributes for a camera. Often, the sharpness and resolution of a camera system are confused and used interchangeably. In this post, I hope to sort out some of the confusion. Figure 1. Same scene captured with two different lenses. In Figure 1, […]
7 Best Zemax Tricks and Tips
By Olov von Hofsten | At Eclipse we use Zemax a lot, everyday actually. But although we know the optics necessary to make optimal optical designs, knowing a software’s hidden shortcuts is not always the same. We recently had Alissa Wilcynski from Zemax give us a three-day course at our site in Stockholm. The course […]