Hacker News

111 points by plun9 2 days ago | 24 comments

dllu 24 hours ago

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-...

0xfaded 5 hours ago

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.

ramses0 5 hours ago

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!

dole 4 hours ago

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

ramses0 4 hours ago

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).

big_toast 4 hours ago

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.

dllu 2 hours ago

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...

trebligdivad 2 hours ago

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

dllu 43 minutes ago

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.

wxw 2 hours ago

These are fantastic, thanks for sharing

Theodores 3 hours ago

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'.

dllu 39 minutes ago

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

plun9 24 hours ago

oh ok

matja 5 hours ago

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 :)

abeppu 5 hours ago

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?

dam_jackalopes 3 hours ago

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

kqgnkqgn 52 minutes ago

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.

andbberger 19 minutes ago

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

Goatsgiats 23 hours ago

These are really lovely.

gerikson 5 hours ago

Very cool images!

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

dllu 2 hours ago

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)

phgn 5 hours ago

Woww so cool, thanks for sharing!

landonalder 4 hours ago

Incredible shots

muststopmyths 5 hours ago

beautiful !