As I said in the title, for all the popularity of “analogue” in some photography circles, this particular kind of analogue gets very little attention.
I’m referring to Slow-scan Television or SSTV.
The principle is the same as the old fashioned fax machine - the image is scanned, line by line, and effectively each pixel is mapped to a certain frequency of sound, according to tone and/or colour.
I think the only use this technology gets these days is in amateur radio circles, as it allows image transmission in the very narrow bandwidth (~3kHz) available in the HF (high frequency) part of the radio spectrum that allows for easy long distance comms.
I’ve never been that enthusiastic myself, until it recently occurred to me that maybe the system, with its heavy “analogue imperfections” could have artistic applications!
Not necessarily via radio - via pure sound, just speaker to microphone works just as well, only a much shorter range.
Many different modes are supported, which could be another rabbit hole to go down, incidentally.
This one was done using the Wraase SC2 180 mode and took over a minute to transfer. The line near the lower edge is the result of a sneeze…
This one was using the Martin 2 mode and was much quicker.
It’s pretty easy to configure - I’m using this app on my phone: GitHub - olgamiller/SSTVEncoder2: Send images via SSTV to transmit via the phone speaker.
And qsstv to receive, running on my Linux laptop using the built in microphone. qsstv has a lot of radio-oriented features, but at least for receiving it works fine on its own.
With the phone volume turned up a range of at least 2m is possible. The mind boggles at what could be possible over a stadium PA system. Myself in garden with unfashionable hat
What do you think - are we about to witness the Next Big Thing in analoue photography?
I show simple methods for converting between Sound and vision, so we can add an echo by processing the image. If we really want to. Sneezing is optional.
But that is digital, not analogue. I’ll have to dig out an old cassette recorder.
Oooh, interesting. I’ll have to read up more carefully when I don’t have a headache… thanks for the link!
I don’t think so… the image formation is line by line, so without some kind of synchronization you don’t really get an image at all. I think…
What might be better is a kind of spectrogram. Audacity has a mode to display files like that. Maybe I should give that a go.
Oh… sorry @lphilpot I think you were responding to Alan’s comment. Sorry! I’ll leave the comment as is anyway in case it’s relevant to anything…
I’m familiar with this and similar. I believe there used to be something in the amateur radio world that was known as ‘packet radio,’ too (and still is, technically).
By the way, @123sg: there’s nothing ‘unfashionable’ about that hat — I have one just like it.
All this ham radio talk reminds me that the only (for me) random sequence of letters and numbers that I can never forget, apart from my national insurance number, is my dad’s call sign GW8HEZ. I probably heard him say it as many times as he said my name. ‘CQ, CQ…’
Quite right. Pure packet radio seems (I’ve never been into it) to have largely given way to newer types of data transfer protocols, but APRS - Automatic Position Reporting System - is popular
. FT8 seems the most popular digital mode at present. You can’t send much useful data with that… but it’s amazing how the tiniest signal can be successfully decoded.
It’s a very practical kind of hat. Gives reasonable sun protection, can be stuffed in a pocket when it’s in the way, and thrown in the washing machine after using it to mop up the accident with the icecream…
Gosh! That would be interesting. Would you actually output input as sound? Or keep the whole process in the virtual world, complete with simulated interference, etc.
I was sitting on a (small) mountain top yesterday saying CQ CQ CQ SOTA, this is VK2STG…
(some photos to come sometime - was an interesting walk/scramble)
I never had the pleasure of meeting him personally, unfortunately, but I know of him; if I recall correctly, he was president of the RSGB back in 1984?
