That bench looks rather clean.
10.02.2026 15:30
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That bench looks rather clean.
Last week I learned that I can use the internal counter on a NI-DAQ board as a triggerable pulse sequence that serves as the clock for an analog output waveform. Pretty cool!
#microscopy
kylemdouglass.com/posts/trigge...
I finally got around to writing the discussion section of our lab's basic training course on live cell #microscopy. I explain the tradeoffs involved in designing an imaging experiment and the art of thinking of the experiment as an optimization problem.
leb-epfl.github.io/basic_traini...
I had the happy realization the other day that conservation of radiance / étendue is purely geometrical. Radiance is just proportional to the size of the set of all lines through two area elements, and the product of area and solid angle is an invariant over this set.
#optics #radiometry
A holiday demonstration of the different penetration depths of red and blue light into tissue.
#optics
When X-rays are incident upon a crystal, some of their energy is reflected from the lattice planes. Certain angles of incidence will lead to the observation of diffraction peaks due to constructive interference between the reflected wavefronts.
#optics #microscopy
youtu.be/FZ4gilAe7x0
The construction of the support of the 3D aperture (a.k.a. the optical transfer function or OTF) using the Ewald sphere in a brightfield microscope under partially coherent illumination.
#optics #microscopy
How to use the Ewald Sphere to determine the support of the 3D aperture of a brightfield microscope under coherent illumination.
#optics #microscopy
Object models for image formation theory in brightfield microscopes.
kylemdouglass.com/posts/image-...
I spent the morning playing with GeoGebra for the first time and, along the way, published an app about aligning a laser beam to an axis in space defined by two irises using two rotating mirrors.
There's a learning curve, but it's not too bad.
#optics
www.geogebra.org/m/tfrykp7y
A Thorlabs cage rod system consisting of a Flir camera and 200 mm microscope tube lens on a photography tripod.
Check out my dope new fixed focal length lens.
That reminds me: I need to set some time aside to revisit this. I tried it about two years ago but found the movement of the optic during handoff from the crane to the table to be quite large. But I recall you telling me afterwards that the movement is repeatable so that you can compensate for it.
It's kind of nuts that most of the cost of kinematic #optics mounts usually covers the alignment phase of a setup, after which the mount serves the same role as an unmovable piece of stock metal.
Trying to get a sense of how much current I can pass through salt water and happened to observe electrolysis by accident.
Do any of you fellow #optics nerds know whether First Contact solution will remove residue from alcohols left behind on glass?
The more I learn about floating point arithmetic, the more I am impressed that scientists can get anything done at all on a computer.
No, it's a much simpler one just to get something working quickly.
I need to learn how to do reflow soldering first to build the one mentioned on the list serv.
Pro-tip: you can use the hole in a Thorlabs FC/PC fiber mount to self-center a domed LED when gluing it to a cage plate blank.
#optics
This week I wrote a small Python library for computing vector EM fields in the focal region of high NA objectives.
github.com/LEB-EPFL/jus...
I'd be pleased if would try it out and leave any feedback or bugs in the issue tracker. :)
Also worth the read: arstechnica.com/ai/2025/06/w...
> Since it's difficult to mechanically define human reasoning at a fundamental level, we can't definitively say whether sophisticated pattern-matching is categorically different from "genuine" reasoning or just a different implementation...
> So Lemkin's attempts to communicate with the AI model... were fundamentally misguides.
Maybe the real, lasting value in LLMs is that they have brought fundamental questions about cognition from scientific specialty to the working lives of everyday people.
arstechnica.com/information-...
I've resorted to printing out code and checking it by hand just to validate AI slop. #thefutureisnow
Last night I managed to find:
- www.machining-4u.co.uk : hooks you up with independent machinists; most ship to Europe
- www.tsprototypes.com : custom machining via CAD file uploads. I think they ship to Europe
Can anyone recommend a service where I upload 3D models of simple machine parts and they mail me the CNC'ed results? Something like Osh Park that does small batches but for machine parts?
I feel like I saw something about this recently but can't remember which platform I saw it on.
Here's a short post about converting the surface sag of a class of common optical surfaces into the normal form of a quadric.
The trick is to use a method from high school #math that doesn't get as much attention as, say, the quadratic equation or the FOIL method.
kylemdouglass.com/posts/comple...
You know you're f***ed when the Wikipedia article on the problem you're working on only exists in one language and it isn't English.
de.m.wikipedia.org/wiki/Umrissk...
I've been using uv a lot recently to specify dependencies for and run single scripts and have found it very useful. Their docs link to a similar PEP.
docs.astral.sh/uv/guides/sc...
I'm brushing up on my computational #geometry skills and found this great resource for surface representations: "Representing Smooth Surfaces" by Ken Takusagawa
Fun fact: surface sag in #optics is just an explicit surface representation.
groups.csail.mit.edu/graphics/cla...
I realized recently that I have always taken for granted the fact that camera read noise is Gaussian, but I never questioned why this is.
The answer, I think, is due to the central limit theorem.
#optics #imaging
kylemdouglass.com/posts/why-is...
Promotional graphic for an SPIE Online Poincaré Webinar featuring Aristide Dogariu from Central Florida / CREOL on "Polarization and polarimetry," scheduled for June 24, 2025, at 6:00 AM PDT. The background is a blurred abstract red design, and there is a photo of speaker Aristide Dogariu in the center.
This month's Henry Poincare Webinar Series on Optical Polarization and Related Phenomena will be led by Aristide Dogariu! 💡
Join us on 24 June for this presentation on light polarization and the statistical properties of the electric field vector.⚡
Register here: spie-org.zoom.us/web...
