How to send a photo around the world in 1926 (2013)

[_Microft]

https://gizmodo.com/how-to-send-a-photo-around-the-world-in-1926-533206646

[dang]

The pictures aren't showing up for me but they're here: https://web.archive.org/web/20130704062401/http://paleofutur...

also the main one is here: https://petapixel.com/assets/uploads/2013/07/pIqE68N.jpg

Edit: and here's the original context: https://worldradiohistory.com/Archive-Electrical-Experimente... - thanks _Microft!

[causi]

It's very interesting to compare this method with its contemporary, the wirephoto: https://www.youtube.com/watch?v=cLUD_NGE370

[jdlshore → causi]

That was fascinating. Thanks for sharing it.

[WalterBright]

The first internet was really the telegraphy network. It even had chat rooms.

https://www.amazon.com/Victorian-Internet-Remarkable-Ninetee...

[teeray]

So it looks like they used an enlarger to basically create a bracketed exposure of the image. There must have been some means to make a raster pattern across all N exposures, and if light could pass through a given exposure it made a puncture in the tape. Playing this backwards, if you have a light shining through 1-N holes in a strip and concentrated through a lens to a point moving in the same raster pattern, it should reproduce the image.

[brk]

A sort of low tech precursor to the fax machine.

[tokai → brk]

Isn't the fax machine from the mid 1800s?

[jonsen → tokai]

"...first commercial telefax service between Paris and Lyon in 1865, some 11 years before the invention of the telephone":

https://en.m.wikipedia.org/wiki/Fax#Wire_transmission

[sidewndr46 → brk]

To me it is actually a digitization of an analog process, then back to analog. The tape with the holes punched appears to be digital (holes are either punched or not).

[justsomehnguy → sidewndr46]

Then a carpet loom is digital too, because it is punch card operated.

[ElfinTrousers → justsomehnguy]

You are correct. We're used to thinking of "digital" as implying "electronic", but that's only because our world contains huge numbers of digital electronic systems.

[sidewndr46 → ElfinTrousers]

The opposite exists as well, "electronic" is conflated with "digital" quite often when it does not mean that.

[justsomehnguy → ElfinTrousers]

> holes are either punched or not

This describes a binary encoding, not a digital process. Otherwise any powerbutton is 'digital', because it's on or off.

[ElfinTrousers → justsomehnguy]

You are also correct: power buttons are digital. Contrast to a dimmer switch that can be set to any arbitrary point in a range.

[jonsen → brk]

For some interpretation of "low".

[anonu]

Love this. I had no idea this machine existed. In an abstract way this was early "digitization". Its incredible how many iterations we had to go through to get to where we are today. But that is the very basis of progress... constant and rapid iteration and refinement.

[proee]

It would be very interesting to see a timeline of all these sorts of communication technologies leading up to present day (latest being SpaceX starlink).

Does anyone have any idea how long this was in use, and what technology replaced it? What is the formal name of this technology?

[greenyoda → proee]

This article has some history of photo transmission: https://en.wikipedia.org/wiki/Wirephoto

Here's the 1970s version: https://petapixel.com/2015/07/26/this-is-how-press-photos-we...

[marricks → proee]

A bit presumptuous to say the latest way to transmit photos is by a specific company. Pretty sure most news papers don’t use starlink.

[shrx]

Why were 5 different exposures needed?

[watmough → shrx]

My reading of the diagram says that 5 different exposures were needed to establish a 5+1 level gray scale.

Note that each picture is scanned simultaneously, and contributes to whether 0 - 5 holes are made in the tape.

At the receiving end, the number of holes controls the brightness of the beam reconstructing the image.

[shrx → watmough]

This makes sense, but I guess you could still achieve the same effect with only one exposure + a configurable readout offset with a variable resistor or something along these lines?

[RC_ITR → shrx]

I think the tape just had 5 channels and each channel related to one level of grayscale.

If the tape had more or less channels, there would be more/less exposures.

[dang]

We changed the url from https://petapixel.com/2013/07/01/how-they-sent-photos-across... to the article it's cribbed from.

Submitters: "Please submit the original source. If a post reports on something found on another site, submit the latter."

https://news.ycombinator.com/newsguidelines.html

[madaxe_again → dang]

There’s no diagram or copy of the photo on the gizmodo article, unfortunately, which makes it less informative than the re-post.

[dang → madaxe_again]

Yes, sorry. I've added links to those at the top of the thread.

[_Microft → dang]

My bad. Here's the actual source, would you mind updating?

https://worldradiohistory.com/Archive-Electrical-Experimente...

[dang → _Microft]

It's ok! these things aren't always obvious.

That's a great link but the blog post adds quite a bit of context so I'll pin it to the top but not change the URL. I hope that works!