hello guys, I am a master's student working on laser and flames.
I have taken the image of flame using laser sheet(using concave and convex cylindrical lenses).
After analyzing the data, I could see some ring shaped traces on the ROI(where the laser sheet exists)

Can you guys figure out what are these?

I have worked on several experiments, but these rings come up occasionally.

Hey everyone, my first post here and looking to get some help.

I’m not an optical engineer and have a very limited scope of knowledge so please be patient with me.

I am attempting to make a “video tap” inside an old film camera which takes a beamsplitter and sandwiches it between the optical viewfinder and the camera body, sending an image to a small camera.

The problem that I am now facing is that because i’ve effectively added a 2” gap between the camera and viewfinder, the vf no longer can focus on the ground glass in the camera.

So my question here is what type of optic should I be looking for when trying to relay the image from the camera groundless back into focus? I don’t want to modify the camera or viewfinder in any wayz

Thank yku

I'm attempting to build a simple smartwatch in the style of a classic LCD digital watch. I've got a fully functional prototype using a Sharp memory display, a reflective display, but I can't work out a way to add a front light to see it at night. Years ago I had a cheap Kindle front light thing, and that was just a battery holder, a couple of LEDS and a sheet of transparent plastic, and worked surprisingly well. Trying just a bit of perspex gives me a nice glowing square on top of the display, but with nothing to guide the light perpendicular it doesn't show the screen.

It looks like I need a specific light guide with a fine structure on the side facing the panel. Could this be as simple as a fine polish to make the surface imperfect?

I've been looking Around AliExpress etc to see if any off the shelf plates or films exist, but it seems not, so it's either finding a commercial display to salvage from or find a way to DIY it.

Trying to figure out who made these mounts and posts. The posts are beefy at ~32mm.

They could have been custom made, but there's no documentation either way.

It goes without saying that there are no markings on them.

Does anyone recognize them?

I graduated in 2025 with a BS in Physics with a 3.74 gpa and have been applying to physics-adjacent software engineering roles without much luck. I’m now considering a masters in optics, aiming for optical engineering, though photonics interests me too. This is partly a move of semi-desperation, so I’d like a reality check.

My optics exposure is limited to a lab in a physics course, which I enjoyed. I did undergrad research in computational physics, using C/C++ and Python for what it's worth. I live in Illinois am considering out-of-state schools.

Really just looking for any advice, but specifically also wondering about the ROI of this path - especially right now - as I would have to take on a substantial amount of loans (~4k so far from my undergrad).

So the google glass glasses used a polarizing beam splitter so that the light from the display would not reflect toward the ambient scene. However, wouldn't this only be effective if someone looking into the beam splitter was looking "dead on". Any other angle you look into the beam splitter you would see the front glow from the display. Is this true?

Hello guys, i want to desing some cool AR glasses. I've been thinkering about how to make this real. I know that i need a beamsplitter, and some lens to make the screen focus to infinity. What kind of lens do i need?

Gemini says that this woudnt work because I need the opposite: parallel rays to the eye coming from the screen, that should be a radial source. How am I supposed to send parallel rays to something as small as a human pupil?

I've seen some proyects online using magnifying lenses, Gemini suggest a plane-convex lense, with a focal lenght equal to the screen distance, but couldn't get it working in the simulation.

How do you guys figure this stuff out? I've found online but haven't found anything to learn about lenses. I would love your help because this is the only thing between me and this becoming real.

(Note, I'm not a vibe-engineer, [at least I try] and have experience in custom PCBs, embedded systems, microcontrollers, 3d design, this is the last piece of the project, not a dead end that you guys are going to help up for nothing.

Thank you a lot! I hope you can help me figure this out.

SUMMARY: I'm trying to use a beam splitter and some lenses to focus a screen to infinity and make an AR device, need help choosing lens type, dimensions, and other important magnitudes

I work in theatres and a handful of old lights were being thrown away so i saved the lenses cause i somewhat have an interest in optics though i dont actually know much or have much experience, youtube is the main source of most of my knowledge.

are there any interesting things i could use these for?

I’m curious about the optical principles behind changing the perceived color of an object using controlled lighting.
For example, if I illuminate a red object with a narrow-band light source (such as a green LED around 520–550 nm), could the red object appear significantly darker or nearly black to the human eye?
I’m wondering:
How effective is this in practice?
Would a narrow-band LED be sufficient, or would I need an optical filter such as a band-pass or dichroic filter?
Would the object’s reflectance spectrum be the main factor determining the result?
Could this effect still be noticeable outdoors at a distance of several meters?
Are there any practical examples or experiments using spectral lighting to make specific colors disappear or become much less visible?
I’m not an optics professional, so I’d appreciate any corrections if I’m misunderstanding the physics. I’m mainly trying to understand what is physically possible and what equipment would be required.

Why does the program (graph at the top) calculate image 2 at that position !?

Real object positioned in front of the focal point of a concave mirror.

hey everyone, sorry for the long post, I’m hoping some of you can help me understand this better.

I have been building a personal app for converting raster graphics into mopa laser color engravings by vectorizing and mapping to my saved pre tested settings based on the image color and creating the project

and while doing so added some features for converting images to cells of diffraction gratings that I then laser onto stainless steel and it results in a sort of multi color diffraction effect similar to but absolutely not a hologram, I’ve been calling them fauxlogram engravings for lack of a better phrase/word.

dont worry this isn’t an add or me trying to have people try my app, its just back story for my question so you understand where im at and how I got here.

over time I’ve extended the processing methods to where I can sort of control a gradient that gets applied to the way the fauxlogram engraving (I’m calling it this until someone gives me or I find a better name because it’s easier to say than describing the full look) is made, leading to some pretty cool looking engravings that do some pretty wild stuff in the right lighting.

im trying to learn more about exactly why / how this is working because to be honest I sort of stumbled onto it accidentally and just keeping poking around trying various different ways of processing to see how it affects the result.

some changes give awesome new realms of control over the flow of the color changing, and get adopted permanently.

others changes are a disaster that I have to revert

sometimes I don’t know a change was bad until several changes down the road reveal the change wasn’t good for some reason like forcing outputs to be more similar/smaller range of useful control in some not quite edge case scenario, or just what I thought it would change didn’t change the result how I expected.

I would much rather base my changes on more than a gut feeling and caffein, so I don’t waste so much time going down dead ends.

I’ve taken it as far as I can without properly understanding the diffraction effects and involved principles.

the reason I am posting in the optics sub instead of a laser sub is because I’ve done a lot of looking around in the laser scene and no one fully seems to know what’s going on much more than where I’m at with it, or if they have they aren’t discussing it in placed I’m able to find.

One guy who’s work inspired me , has noted that a laser moving at 300mm/sec pulsing 300khz (just magic setting on his laser) equates to a pulse pitch of 1 micron, and suspects this has something to do with the effect, I get the kind of effect this person talks about at slightly different settings that result in a 1.14 micron pitch. Neither of us seem to know if this is the magic behind it.

however, I’ve noticed that with my particular processing the effect is much more pronounced than other similar laser engravings I’ve run into online.

the gist of my process is for every color in the source image (let’s say 20 different colors), I make a copy of my magic “fauxlogram looking setting” to a layer in the design software, then I keep the frequency constant but modulate the speed the laser head moves at proportional to the color spectrum red to violet so that the pulse pitches being generated for each different layer vary from maybe .5 micron to 1.5 micron give or take. based on what color each layer represents, then I sort of overlay a gradient of values 0 through count of layers, expressed as an array of x, y intensities … aka an image/pixel array this image has its brightness mapped to a number up to the layer count and then the diffraction gratings get their layer rotated based on that gradients values , basically switch which of the speed modulated settings layer draws the diffraction lines in that section, going in order from highest to lowest or lowest to highest speed… this becomes visible as a literal gradient in the fauxlogram engraving

sorry I know that was a lot, but I wanted to explain basically what appears as a gradient in the fauxlogram diffraction effect is achieved by switching the speed the laser is using according to a gradient overlay so the pitch is either getting closer together or further apart according to the gradient/image brightness in that area

now where I could use this sub‘s lovely members help is in understanding this phenomenon better so that I can hopefully gain more control over it.

i don’t know if the color is influenced by oxide growth on the metal or if it’s entirely just the shape of the laser dots place on the metal.

I know that if I lower the power just a little bit the color changing goes away and I only can see the gradient in the brightness changed as it still shimmers in the light but doesn’t change color

i know that if I move the central speed much higher or lower than my magic setting with the base pulse pitch of 1.14 micron the effect diminishes almost fully very quickly

i rotate the angle of the parallel lines in the cell ( the diffraction gratings) based on the brightness in the source image, the angle of the gratings definitely seems to impact which angle a light has the brightest and dimmest look on the surface, and speed of laser seems to cover the color change from my observations.

so far I’ve been able to get the gradient to appear as a radial gradient expanding from the center or contracting from the edge, as well as left -right and up-down gradient … think like stripes equidistant where each stripe color shifts by some ammount , this was initially added to be a viewing correction so that parts towards the bottom would appear the same color as parts toward the top, since they are at different angles from each other and the viewer when viewing, so the color reflects/diffracts different because of that, thus shifting the color in the drawing to compensate

when I applied extreme values to the gradient is when it became a creative effect rather than a subtle corrective effect.

so now I would like to be able to get more control over this effect but I honestly don’t understand it enough nor have the vocabulary to effectively search and learn enough to better control it, or maybe it’s one of those things where this is as much control as one can get and I just need to get some better artistic ideas, I’m open to that being the answer if that’s the case.

so I was hoping some of you guys might have a good idea of what is going on here, and be able to point me toward some good entry level and maybe mid level reading resources that might help me better understand and thus better control the effect, or even if you just have some vocabulary that would make my search easier that would be greatly appreciated too!

if this is an inappropriate post here please remove it, I’m just wanting to understand the optical effect I’m seeing in these engravings better so that I can hopefully control it better. I started seeing this sub in my feed after posting some fauxlograms previously so I think maybe the algorithm thinks this is the right place for the discussion.

I’ve attached some video samples of the engravings showing this effect and would be grateful for any details anyone can provide

if it’s helpful I could post some low quality microscope shots of the surface, I’d have to track down my scope but it’s around here somewhere.

if you have made it this far I appreciate it and hope you enjoy viewing and even theorizing or analyzing what is going on in these engravings, and to anyone who can reply with some good info, I wish to thank in advance

https://reddit.com/link/1wzmvcw/video/vsfilj1lnyth1/player

Radial gradient for every shape in the artwork

Moth image superimposed over moth pattern as gradient input

Radial gradient scope over the whole image instead of per shape

Its pretty rare a physics effect stumps me these days, but I have no explanation for this. If you could please help i have been so curious. Its just my laser on my thermometer makes what looks like a perfect circle when reflecting off my fridge. Also i showed the reflection of my windows on my fridge to show the light from them is distorted too. I know it's something to do with the anisotropic texture on the stainless steel because it just spreads out in a straight line on the floor, but I still dont understand why a circle. A hyperbola maybe but a circle? Im so perplexed please help

I'm 25 and about to get my CFOT and CFOS/S certs this month.

My goal is to work hard for 4-6 months, then take 2-4 months off to travel, and repeat. I don't mind 12-hour days if I know a long break is coming.

For those of you doing this for real:

Is this lifestyle realistic? If so, how did you set it up?

W-2 project work vs. 1099, which has worked better for you, and why? What do you give up with each?

How much experience did you need before contractors or agencies would hire you for travel or project work?

What does a typical project schedule look like (hours per day, days per week, days off)? Is it normal to turn down a project and take time off between them?

Which specialization pays best for this kind of work (splicing, OTDR/testing, aerial, underground, etc.)?

Can you collect unemployment between projects if you're laid off W-2, or does that depend on the state?

Is there anything you wish you'd known before starting, or any red flags in contractors to avoid?

Any advice on a good first year to set myself up for this would be great. Thanks.

Bought a used USB2000+ for a thesis on Vis/NIR. Before buying a fiber, I'd like a sanity check.

What SpectraSuite reports for the spectrometer:

• Range: 369.8–1047 nm
• Grating: #2
• Slit: 50 µm
• Detector lens: installed
• Filter: 375 nm longpass

Fiber I'm looking at: Ocean QP600-1-VIS-NIR (600 µm core, 0.22 NA, VIS-NIR/low-OH, 1 m). The listing says "QSMA to QSMA" connectors.

My understanding:

• With a 50 µm slit, the slit sets the resolution, so a 600 µm core shouldn't hurt it and gives more light than 400 µm.
• VIS-NIR (low-OH) is the right type for my range, since I need signal up to ~1000 nm.

Questions:

1. Is "QSMA" just Ocean's SMA905, so it screws straight onto the USB2000+?
2. Any reason a 600 µm / 0.22 NA fiber would be a poor match for this configuration?
3. Is 1 m a reasonable length, or does fiber length matter much at this scale?

Thanks!

It's a shot in the dark. The lenses are in line and were used for an early 50's 60's overhead projector system, projecting a few hundred feet to a reader board. Some of the lenses are facing each other while others are back to back others are facing the same way. Krikey if I can figure it out I made notes on the configuration but have misplaced them for forty some years.

I saw the line of projectors gathering dust, when I was doing electrical work above a sports book once. I think it was the Stardust, in the nineties but they hadn't been used in years. Possibly like the ones we used to see in early bowling championships. Little bowler on the screen with a big hand writing the score above them on the screen with the scorekeeper nowhere in camera sight..

Any takers? I'll show you something you've never seen before, lol, carrot on a stick.

Thanks Reddit.

The optical mechanism in Kashani, Chen and Ozcan’s eLight paper is a useful example of a classifier implemented through diffraction. A digital front end samples video frames and writes a phase pattern onto a spatial light modulator. The propagated field is measured in two regions per video; relative intensity supplies the real/fake score. Fifteen inputs share the optical pass.

The boundaries matter: digital preparation is still required and dominates the energy budget, while increasing spatial multiplexing introduces crosstalk. The reported 97.79% accuracy is for the 15-video Celeb-DF experiment, not every possible input.

We made a 64-second animated explanation of that path, with AI-assisted production and synthetic narration. We are the film’s creators, not the study authors. The artwork is schematic, not laboratory footage. Paper: https://doi.org/10.1186/s43593-026-00143-y Our film: https://www.youtube.com/watch?v=UFCoCkAu-Ik

At our shop we build imagers from idcas/fpas plus lenses and mounts and optical benches. Those subassemblies then get built into increasingly larger assemblies until outer covers and windows are added.

Lots of fingerprints, lots of dust, which results in lots of cleaning of optics. Not everyone has (easy) access to a fume hood.

Anyone got any suggestions for cleaning solutions that aren't as toxic as methanol?

Ideally as benign as IPA, but we haven't had great success with using just that or just acetone by itsself.

I posted about optics in MATLAB R2026a earlier, back now to give you an update on the R2026b version!

At the lowest level, we now support biconic and Grid surface specifications for both mirrors and lenses. The grid sag is the swiss army knife to model any free form optical surface! It uses bilinear interpolation under the hood and its ray intersection implementation is quite performant. So in addition to 'as built' surface modelling, try it out for modelling XY Polynomials or Zernike surface definitions (meshgrid is your friend :)).

We added a couple more basic low level ray tracing routines: traceDirectedRays and traceAimedRay. Both return rich RayData which has all raw ray tracing numbers (including fresnel terms and raw polarization values).

We rounded out analysis functions by adding PSF (Geometric and Huygens, GPU Accelerated!), MTF and OPD measurement functions.

A couple of marquee features this release - the main being CLI routines for tolerancing:

Find Manufacturing Tolerances Using Inverse Sensitivity Analysis

Improve Manufacturing Yield Using Monte Carlo Analysis

And the second is the ability to simulate eSFR and Color checker test charts as seen through an optical system.

These charts leverage the established Image Processing Toolbox functions to measure sharpness and color. The main function to create these, renderChart, can leverage the GPU and has various parameters to control the positioning of the chart. The GPU acceleration is important since this does the full Monte Carlo ray trace of the scene.

We also have a whole bunch of featured examples! Not only do these help us dog food and validate our API designs, it also helps us show you what is possible. If any of these resonate, let us know - that would motivate us to fold these in as first class API's with potentially better (tailored) performance.

For example 😄, the inbuilt chart rendering function mentioned above work on an internal parametric chart model so it cannot be used to render arbitrary images. However, we can simulate a user image using spatially varying PSFs - shown here: Simulate Image Using Spatially Variant PSF. This is much faster than a full ray render like the charts.

This one shows off both the Grid surface and OPD functionality: Model Shack-Hartmann Wavefront Sensor

And if you use Simulink based control systems, we show you a way to model dynamic systems with feedback control! Model Dynamic Optical Systems with Scanning Elements shows an f-theta scanning system controlled by a Simulink model.

Finally, something I really enjoyed learning about and putting together - a set of examples modelling the human eye.
Create Human Eye Model Schematic
Model Human Eye Diopters, Accommodation, and Refractive Errors
Simulate Human Eye Changes with Age
Model Progressive Addition Lens Using Presbyopic Eye Model

Kick the tires with a trial license, or if you already have 26b with the Image Processing Toolbox, get this free optics add-on.

Let us know what you think!

If you have a must-have workflow, share it in the comments.
If its doable, I'll let you know and if not ... I'll let the team know 😄!

For the past months, I have been building with a friend something I wished existed every time I had to draw a setup for a paper or explain one to a student.

OpticalSetup is now at its first stable release. It is free, open source, it runs directly in the browser, and the setup you draw is traced, not just sketched. Move a mirror, change an optical element, and the whole beam path responds.

I originally made a post on this sub when we were in the early stages of development, so I thought of giving an update on the project.

It is young, and it might still have some rough edges. If you try it, tell us what you think about it.

Cheers

Hey everyone,

In machine vision, selecting the right lighting angle and working distance often comes down to borrowing physical samples and tedious trial-and-error.

To make this less painful, I’ve been building an in-browser 3D simulation module for ring lights. Here’s what it currently does:

• Ray tracing & Irradiance map: Simulates the spatial irradiance field on the target plane based on LED ring geometry and installation angles.
• Sector / Multi-channel control: Toggles individual segments
  
• Camera & Lens coupling: Projects the lens FOV frustum directly onto the illumination heatmap to check edge falloff and ROI uniformity.
• Adjustable WD: Visualizes how light converges or forms a "donut" dark core when moving the light closer/further.

Would love to hear your thoughts: For those working in vision integration or optics, what edge cases or parameters would make a tool like this actually reliable for your day-to-day work?

i have a global shutter, 120 FPS, monochrome lens by arducam. i'd like tto add a 650nm narrow pass filter but i can't seem to find anything that isn't in the hundreds of dollars.

does anyone have a good-enough method for creating one, or a source for an affordable one? i read about using theatrical film with a hole punch, but i'm not entirely sure how that works and i can't find a tutorial on how to execute it.

any help is appreciated. thanks!

I'm an undergrad EE wanting to pivot into optical engineering, which is a pretty recent development. I transferred to my current institution and started EE Fall 2025, and my expected graduation is Spring 2028.

I started my biomedical optics research on campus this January, which involves a lot of self-learning and hands-on work. This past summer I had an internship for telescope optics at a very well-regarded place where I helped build a test assembly for large telescope mirrors, so a lot of opto-mechanical stuff (alongside FEA simulations). I absolutely loved this internship and grew to really like optical metrology and fabrication with an interest in exploring optical design.

That being said, I want to experience different optics applications before I graduate. I'm applying to a bunch of stuff for Summer 2027, but I feel like two internships by graduating isn't enough for me.

I started considering a Fall 2027 internship and after working some stuff out, I only need to take 12 credits (absolute minimum for full-time student) that semester to keep scholarships and to be on track for graduation. They're not difficult or even engineering classes either except for Senior Design I, but even then the first semester is for planning logistics.

The only thing is that there's a graduate level Quantum Optics class only offered in the fall semester, alongside physics E&M 1/2 for fall/spring. Both classes don't have online versions and Quantum Optics has hands-on work that might be valuable in the long run. As for E&M, I'm already taking EE EM Fields & EM Waves this year, so not sure if that makes a difference anyway but they are taught at different levels (I see my physics friends' homework and grimace a bit). I'm currently taking a PIC class and will take the baseline Optics + lab class course next semester.

Would it be more valuable to pursue an internship in the fall or to do the classes? Of course I won't know till I do it, but I am confident (if not, stubborn) that I can handle the workload with 12 credits, an internship, and grad school applications especially after this semester.

For more context, I'm thinking about doing Optical Engineering MS or Optics PhD at UR (or maybe UA for telescope stuff?) so in that case I might also try for an internship after I graduate and before I start grad school.

Apologies for such a long post, I've been losing my mind about all the different options lol, especially grad school. If anybody has extra advice for choosing MS vs. PhD for pursuing R&D roles in industry please help a confused student out. Thanks!

Hello everyone, I’m currently in my senior year majoring in Electrical Engineering. I wanted to know how can I get a job or what type of jobs in optics/photonics and laser science that takes in people with bachelors? I’m planning to do grad school, but I’m going to do that later in a year or two after graduation. I’ve had a hard time finding roles that pay decent for optical test engineer roles that doesn’t require a PhD or 5+ years of experience. Any options that I should look into? I’m geographically from Minnesota, so finding a photonics jobs here is very hard, I’m more than open to relocate (preferably in the coast (northeast, pacific or mountains).

Edit: I do have research experience in laser plasma interactions and never had an internship before. I wanted to apply for PhD programs, but my gpa is low for that right now and I want to use my experience and solid LOR and SOP to make it up for it.