alexbock

5 ms·

1.
by alexbock 1y ago
I'm guessing you're referring to https://news.ycombinator.com/item?id=39309409
2.
by alexbock 1y ago
Thanks. I did not use any frameworks/libraries/dependencies for this project. It's vanilla JavaScript/HTML/CSS from scratch. The general concept of a spreadsheet-like data editor next to a visual view is a standard
3.
by alexbock 1y ago
If you want to play with any of these lens descriptions (or look at code for simulating them), I made a free and open source visual web UI for lens design. The default project when you visit it is a double gauss lens similar to the one show
4.
by alexbock 2y ago
> (This is mathematically worse for a reason I don't remember; it causes any picture taken at a concert with blacklights or blue spotlights to look bad. The iPhone camera sensor is prone to saturating and clipping the blue channel w
5.
by alexbock 2y ago
Tesla vehicles display error descriptions prominently whenever an error code is presented, and detailed error diagnostics are available for anyone to browse in the service mode menu on the touchscreen. (Service mode is publicly accessible b
6.
by alexbock 2y ago
> All the "affordable" consumer FLIR options suffer from low resolution and/or low response time. When I experimented with connecting two thermal cameras to a VR headset for stereo thermal vision, I used two Seek CompactPR
7.
by alexbock 2y ago
I've always been fascinated by this topic as well. As a further experiment, you may be interested to know that these IR lights can pass straight through red wine that looks totally dark and opaque to the human eye. I took some photos t
8.
by alexbock 3y ago
I learned of the interesting "spite clause" described in the will section of this article while reading about the common law rule against perpetuities, which limits how far into the future wills can operate. [The word "bizarr
9.
Wellington R. Burt "had one of the more unusual wills in American legal history"(en.wikipedia.org)
2 points by alexbock 3y ago|1 comments
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by alexbock 3y ago
It sounds like you're thinking of separating coins using eddy current braking [1]. This works even for non-magnetic coins because the effect is a function of the metal's electrical conductivity. If you have a silver coin or a smal
11.
by alexbock 3y ago
I've always been surprised that Apple added this functionality to the iOS home screen without having a solution to the reorder vs nesting UI problem. Trying to move an app into a folder often results in the folder deciding to fly out o
12.
by alexbock 3y ago
The single most important and most revealing aspect of this announcement is Apple's framing of the promotional images showing the face display on the front of the headset. I think the large R&D investments tech companies are making
13.
by alexbock 4y ago
The center of the image it produces is perfectly sharp, but using a single achromatic doublet as a photographic lens at f/2 necessarily produces significant eighteenth-century softness as you move out to the edges. This image [1] taken
14.
by alexbock 4y ago
I enjoy monochrome infrared photography at wavelengths longer than 1000 nm using a Sigma sd Quattro (no Bayer filter and the sensor IR filter is reversibly user-removable). To reduce exposure times as much as possible, I've been testin
15.
by alexbock 4y ago
Producing a non-inverted image with only two lenses per eye and no additional prisms implies a Galilean telescope with a convex lens as the objective and a concave lens as the eyepiece. Zeiss makes distance magnifying eyeglasses using this
16.
by alexbock 4y ago
> Are there algorithms to select the lens elements for me given the properties I want? I plan to add optimization features in the future to automatically tune design parameters to suit specified target criteria, as well as some applicati
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Show HN: Open Optical Designer, free and open source lens design software(alexbock.github.io)
59 points by alexbock 4y ago|5 comments
18.
by alexbock 4y ago
If you want to work with 5000 nm - 10,000 nm in that price range, you can use an affordable thermal camera with a microbolometer sensor. Surplus silicon and germanium lenses can sometimes be found cheap on eBay, and there are always a lot o
19.
by alexbock 4y ago
I originally heard about it from this page written by a group who silvered a 28-inch mirror this way: https://sites.google.com/site/spraysilveringtelescopemirrors... It's still ultimately a silver nitrate reductio
20.
by alexbock 4y ago
I made several attempts at acetone vapor smoothing on mirrors printed in ABS and ASA and the surfaces always came out very well polished at the micrometer scale but unacceptably warped, wrinkled, or patterned at the millimeter scale. The be
21.
by alexbock 4y ago
I do it using a $400 Prusa Mini and epoxy resin: https://alexbock.github.io/blog/3d-lenses/index.html It's surprisingly easy to 3D print the shape of a lens and polish by hand. I made a working telescope this
22.
by alexbock 9y ago
The Migratory Bird Treaty Act is very interesting from a legal standpoint. Regulating wild birds is not one of the enumerated powers of Congress, but the federal government entered a treaty with Canada to protect migratory birds and success
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by alexbock 9y ago
You do not need a Federal Firearms License nor registration as a Special Occupation Taxpayer to purchase fully automatic weapons that had been registered in the National Firearms Registration and Transfer Record prior to 1986. All of the ot
24.
by alexbock 9y ago
The human eye has some interesting optical defects like chromatic aberration that man-made optical systems usually fix in hardware but that the brain fixes in software. These aberrations, when available to the software as uncorrected input,
25.
by alexbock 10y ago
The speed of sound is probably more in the latter category as it is dependent on altitude and temperature, and even then only after assuming that someone really meant the speed of sound in air. If I search for "speed of sound" Goo
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by alexbock 10y ago
Use of Wine with QEMU was still a recurring topic even on Intel Macs (until this release) because 64-bit Windows binaries use a calling convention that isn't compatible with macOS.
27.
by alexbock 10y ago
They performed this with and without that payment. "This paper reports results from two novel experiments designed to distinguish sincere from expressive partisan differences in responses to factual questions. In both experiments, all
28.
by alexbock 10y ago
Using a card-counting computer at a blackjack table in a licensed casino would be illegal in Nevada under NRS 465.075 ("Use or possession of device, software or hardware to obtain advantage at playing game prohibited"). I've
29.
by alexbock 10y ago
Not very much, the 15-inch has a 76 Watt-hour battery [1] and putting 152 of those into Wolfram Alpha gives less energy than a gallon of gasoline [2]. [1] http://www.apple.com/macbook-pro/specs/ [2] http:/&#
30.
by alexbock 10y ago
Safari has this built-in under "Develop->Enter Responsive Design Mode" (⌥⌘R). The Develop menu can be enabled from the Advanced tab of the Preferences window. Firefox appears to have a "Responsive Design View" (⌥⌘M) a

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