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-...

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.

I took one of my baby on the swing. It needed custom polar coordinate dewarping:

https://i.dllu.net/swing_07_7668f7f16ff7ac2a.png

Also motorcycle cops:

https://commons.wikimedia.org/wiki/File:San_Francisco_Police...

This is sick, dude! I liked the formatting of the website, quality of photos, and minimization of extra fluff.

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.

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!

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

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).

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

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.

These are fantastic, thanks for sharing

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'.

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

oh ok

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 :)

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?

From what I understand, the grants to restore the old railcars don't come from their general funds (and if they decided not to do them, they wouldn't get the money). But I'm sure a lot of the regular maintenance comes out of their regular budget, and I agree that's a difficult thing to justify.

I wish they could do something about fare evasion. I ride Muni fairly often (both buses and trains), and I see maybe 20% of people paying when they get on. I know some of the remaining 80% probably have monthly passes or something and don't strictly need to tag on, but I can't imagine it's a large percentage. Biggest offenders seem to be out-of-towners who are going to Chase Center or Oracle Park events (I live in the Dogpatch and see a lot of that on event days). There's no excuse now that the fare terminals accept NFC credit cards too (and not just Clipper cards). I expect getting more people to pay could solve some of these funding problems, or at least make them less severe.

(I do wonder if the cost of fare enforcement exceeds what they'd recover in fares, though...)

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

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.

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/

Re https://www.streetcar.org/remembering_a_trolley_titan/: that would make a great HN submission in its own right! We should just let enough time go by so it doesn't count as a follow-up [1].

Would you be up for posting it in, say, a couple months and then email hn@ycombinator.com? We'll put it in the SCP [2] for sure, so it will get a random placement on HN's front page.

[1] https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...

[2] https://news.ycombinator.com/item?id=26998308

Sure; can do!

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.

Apparently the cable cars have by far the highest cost to operate per hour anyway.

At 2024 numbers in this SPUR report:

Cable car 872 streetcare 631 lightrail 412 system avg 327 motorbus 302 trolleybus 281

So canceling each cable car could IIUC, allow the system to add roughly 3 electric buses.

https://www.spur.org/sites/default/files/2026-03/SPUR_Taking...

These are really lovely.

Beautiful pictures!

Very cool images!

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

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)

Woww so cool, thanks for sharing!

Incredible shots

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

beautiful !