Hacker News

Top stories

Live mirror
30 storiesupdated just nowView source snapshot
  1. GPT-6 Sol and Luna(openai.com)
    256comments
  2. Claude Opus 5.5(anthropic.com)
    554comments
  3. OpenAI GPT–6 Astra breaks Enigma message that has resisted solution since 2005(cryptocellar.org)
    314comments
  4. Claude Opus 5.5 Intelligence, Performance and Price Analysis (Max)(artificialanalysis.ai)
    34comments
  5. WordPress: Unauthenticated path traversal leading to conditional RCE(github.com/wordpress)
    33comments
  6. There's a high chance of devices being sold with GrapheneOS preinstalled in 2027(grapheneos.social)
    54comments
  7. OpenAI is well positioned to fast-follow Jev(arcturus-labs.com)
    144comments
  8. 16-bit Intel 8088 chip (c. 1985)(allpoetry.com)
    10comments
  9. Launch HN: Coverage Cat (YC S22) – Umbrella insurance via your personal agent(coveragecat.com)
    16comments
  10. Writing Rust code that's fast by asking agents to make the code faster(minimaxir.com)
    31comments
  11. Apple has added persistent 'ads' to iOS, and it's driving users crazy(techradar.com)
    338comments
  12. George Lucas Returns to Earth, Bearing Gifts(commonedge.org)
    3comments
  13. Show HN: AI·rete·RAG – a Rete rule engine decides, RAG explains why(ai-rete-rag.com)
    1comments
  14. Solitaire Alone Together(solitairealonetogether.com)
    23comments
  15. Show HN: Drop – A rootless Linux sandbox with gVisor support(droprun.sh)
    41comments
  16. Unreal Agent(unreallabs.ai)
    1comments
  17. Zero-downtime Linux kernel zero-day mitigation via eBPF and SECCOMP(github.com/mc493)
    discuss
  18. Can gzip be a language model?(nathan.rs)
    132comments
  19. AMD's random number generator can't generate a 0?(flatassembler.net)
    163comments
  20. One Minute Park(oneminutepark.tv)
    5comments
  21. Truman World(trumanworld.live)
    29comments
  22. Show HN: InstinctFlash – Run 5B world-action models in real time on Jetson Thor(github.com/general-instinct)
    1comments
  23. The Economics of Open-Weight Inference(ornn.com)
    24comments
  24. Relativistic raytracing(publish.obsidian.md)
    5comments
  25. Training a model to identify AI-generated web content from structure alone(arxiv.org)
    2comments
  26. MUNI Heritage Weekend in San Francisco(lawrence.lu)
    26comments
  27. Pentagon: Palantir AI Overreliance Led to Strike Killing 123 Iranian Children(gizmodo.com)
    2comments
  28. Side-stepping the Secretary Problem, unwittingly(evalapply.org)
    1comments
  29. I asked Meta’s Muse for its filesystem and it sent me 6.8GB(mouse.dev)
    127comments
  30. Meta’s Muse has a serious 0-day(arstechnica.com)
    40comments

MUNI Heritage Weekend in San Francisco

119 pointsby 1d agodaniel.lawrence.lu
26 comments
1d agoHN ↗

OP here, ask me anything! I've also written about the process previously:

- Line scan camera image processing: https://daniel.lawrence.lu/blog/2025-09-21-line-scan-camera-... Previous discussions:

  - https://news.ycombinator.com/item?id=44996938

  - https://news.ycombinator.com/item?id=46383593

  - https://news.ycombinator.com/item?id=46388084

- Standalone line scan camera hardware: https://daniel.lawrence.lu/blog/2026-06-12-standalone-cnc-li...

- Line scan camera image processing 2: https://daniel.lawrence.lu/blog/2026-08-02-line-scan-camera-...

5h agoHN ↗

Very cool.

I never thought about it until seeing these, but line scans yield an orthographic projection in the scan direction. There was a little bit of uncanny valley being able to see parts of the front/back of the car that would have normally been compressed out occluded by perspective.

4h agoHN ↗

Yarp... Mr. Lu, please go to your nearest gigantic poster shop and immediately start selling these prints at art-gallery prices! There's a brief moment in time where you've a monopoly on "pictures that look like this" and you'd probably be able to make your money back (and more) on this highly distinctive photograph style. Do some back and forth chat with AI on "fine art photography pricing structure" and "signature style / visual voice" and you'll likely be pleasantly surprised.

...and I'll be surprised if I don't see these pictures hanging in a bank/startup lobby at some point!

4h agoHN ↗

Hell, I'd shop them around to transit authorities. Gorgeous photos, awesome hardware and processing techniques that went into them.

4h agoHN ↗

Donate copies to sfmuni (no matter what!), or front them as "distribution partner", ie: they sell those posters for $999.99 or whatever and cut checks to Mr. Lu for $99 each (or something).

3h agoHN ↗

Your other photos are always very pleasant to look at too. Thank you for sharing them.

Are there other photo types you've thought about taking? (I don't know very much about the topic. Rocket launches? Cruise ships? 360/Cylindrical line scan sweeps?)

I assume the train rails and constant motion are part of the appeal of making trains the subject. I can't exactly think of parallels, maybe a factory assembly line.

3h agoHN ↗

I have a long-standing dream to use a line scan camera from a moving train, assuming everything would be easy, if I had the camera. Little did I realise how much work is needed to tidy up the imagery!

Your work is extremely beautiful, and I am truly envious of your work, the aesthetic is awesome. I want to do it on the cheap though, with a regular phone as camera.

I think you have given me the directions needed to make some bold steps towards getting what I want out of the 'medium'.

1h agoHN ↗

If you want to use a regular phone or camera, check out TrainScanner!

https://github.com/vitroid/TrainScanner

It converts a regular video into a line scan style photo. It works by stitching together small chunks rather than 1px thin slices, so the background has a repetitive texture rather than being smooth horizontal stripes. But at lower resolutions, it looks similar, especially if you pick a spot with a clean background. Also the trains turn out very detailed.

Example work by Kakeyama from Japan using this: https://kakeyama.fan.coocan.jp/tec/e5e8r.htm

2h agoHN ↗

They're great - I'm pleasantly surprised there's no blur on the people.

1h agoHN ↗

If people are moving, they may get stretched or distorted. But they won't ever get blurry, since the capture rate is like 10,000 lines per second.

5h agoHN ↗

Very cool images!

What lens are you using? Does it have to cover 135 format?

1h agoHN ↗

Muni heritage weekend was shot on my new Voigtlander Apo Ultron 90mm f/2. The line scan camera's sensor is 28mm long so any APS-C lens will work, not necessarily full frame. I modded my line scan camera from Nikon F mount originally to Sony E mount so that I can use more compact high quality lenses like M mount ones.

Previously I've also used these full frame lenses:

- Myutron 50mm f/2.6 (Shinkansen N700A, SF Cable Car 2017)

- Voigtlander Nokton 58mm f/1.4 (Brisbane Queensland EMU)

- Samyang 135mm f/2 (Madrid AVE Class 102 and Shanghai maglev)

- Voigtlander Apo Lanthar 125mm f2.5 (Yamanote Line, CR400AF)

- Voigtlander Apo Skopar 90mm f/2.8 (London Tube photos)

- Voigtlander Ultron 35mm f/1.7 (Hong Kong trams)

and APS-C lenses:

- Cheecar 50mm f/1.2 (Osaka trains)

- Samyang 85mm f/1.8 CS (Caltrain)

4h agoHN ↗

I like the photos, they look like architectural diagrams.

I suppose the subjects moved past the camera perpendicular to the lens direction, so you only see one side.

Are there any examples of what it looks like with a line scan camera when a subject goes past at an angle?

Also, for anyone setting up a tripod with a tripping hazard in public, do consider public liability insurance :)

4h agoHN ↗

Ok the photos are cool and it's nice to see the vintage street cars. But Muni has a budget shortfall and is planning on cutting a bunch of bus lines and reducing frequency on lines across the system. Meanwhile, it has an internal supply chain to custom build replacement parts for vintage vehicles that no other city will operate, and teams of specialist restorers. Viewed in isolation, they look cool! Viewed in context, is this ... irresponsible?

2h agoHN ↗

Depends on what value you place on the vehicles I suppose.

1h agoHN ↗

The photos are really cool, and I do like trains and infrastructure in general.

But came here to say the same thing. There is an advertising campaign in SF right now to encourage people to vote to give Muni more money (again) in November, because they can't cover their essential costs. This...looks pretty non-essential to their core mission to me.

They should have done everything they can inside their org to cut costs, before going to ask residents to give them more money.

Now I hope - maybe this is primarily funded by donations / grants or volunteer work, and SFMTA contributes very little to this. If so great - but it would have been wise for them be very clear about that.

9m agoHN ↗

I'm a member of Market Street Railway (https://www.streetcar.org/) which does a lot of advocacy to keep these street cars maintained. Many of these cars were either purchased long ago from other cities that would have otherwise scrapped them (most of the PCCs, the long sleek ones) and others are often either preserved MUNI originals or donated / purchased by Market Street Railway. Car 162 just came back into service and was purchased by Market Street Railway and worked on by volunteers (and MUNI) [1]

I obviously am I biased, and think this is very very cool. There are many intangibles here beyond the budget numbers; a bit of history, a bit of whimsy, a bit of color to what is often utilitarian (public transit). It certainly attracts tourists to the city (I was pretty surprised at the number of out of towners at MUNI heritage weekend).

But I do think it's important, not just for tourism but also as a legitimate connector along the Embarcadero corridor that otherwise has no public transit along it. Agree that a breakout of the cost of maintaining these things would be appreciated, not sure if that exists in clear terms, but I don't think it's massive. For example Car 162 was damaged in a collision in 2014, and took 12 years to fix and return to service. For many gripmen / MUNI restorationists working for the city, it's a side project.

And while I'm here, I'd be remiss if I didn't post an article about Maurice Klebolt, one of the biggest advocates for vintage transit in San Francisco. It describes how he acquired car 106 from the Soviet Union [2]

[1]: https://www.streetcar.org/streetcars/162-162-muni-1950s-live...

[2]: https://www.streetcar.org/remembering_a_trolley_titan/

39m agoHN ↗

looks like the one time cost for doing a renovation is around $1m per car, and are funded by spot grants rather than the general budget. I was unable to find the overhead involved in ongoing maintenance, but it looks like killing the F line is already on the table.

58m agoHN ↗

every weekend is muni heritage weekend while they continue to operate the F as a museum