The SOS in Lanterna BLA is real Morse. Three short, three long, three short, with exact timing from the international standard. Not a decorative blink. Not a random rhythm that looks like SOS. It is the code that rescuers, military, pilots and sailors have recognized since 1908, now running on the iPhone camera LED, inside a flashlight app. It seems like a detail, but it is the kind of detail that separates a utility app from a theater app.
Worth recalling what Morse code is, for whoever never paid attention. It is a system for encoding letters and numbers into short and long pulses, created by Samuel Morse and Alfred Vail in 1837, originally for transmission over the electric telegraph. Each letter of the alphabet becomes a combination of pulses. The letter S is three short pulses. The letter O is three long pulses. Together, S, O, S forms the international distress signal, officially adopted on October 3, 1906 by the International Radiotelegraphic Conference in Berlin and in force since July 1, 1908. The choice was not for the letters, it was for the pattern that is easy to transmit and easy to recognize even in poor conditions. Three short, three long, three short, in loop, is the most recognizable way ever invented to ask for help.
But Morse has timing. It is not any rhythm. The recommendation ITU-R M.1677-1, maintained by the International Telecommunication Union, defines that a short pulse (dot) is the base unit, and a long pulse (dash) lasts three units. The interval between pulses inside a letter is one unit. The interval between letters inside a word is three units. The interval between words is seven units. By changing the duration of the base unit, you change the speed of the message, but the proportion is fixed. Whoever learns Morse learns that proportion first.
Lanterna BLA uses two hundred milliseconds as the unit. The dot lasts two hundred milliseconds. The dash six hundred. The interval between pulses inside the letter S and the letter O lasts two hundred milliseconds. The interval between letters lasts six hundred milliseconds. The interval between repetitions of the whole SOS lasts one thousand four hundred milliseconds, seven units. Each of these numbers is in loop inside the flashlight controller of the app, reading the rear camera LED via AVCaptureDevice. The LED lights up at two hundred, goes off at two hundred, lights up at two hundred, goes off at two hundred, and so on, for as long as you leave the preset active. No randomness. No variation. International standard Morse, period.
Most flashlight apps on the App Store have an SOS mode that does not respect this specification. They blink at an arbitrary rhythm, at a decorative frequency, in the pattern the developer thought looked cool. It works as generic visual attention, but it is not Morse. A trained rescuer, who looks at an SOS signal in the middle of the dark and tries to figure out whether it is a real distress call or just a light blinking, will be able to tell. Lanterna BLA respects what it is doing. Whoever knows Morse will see real SOS. Whoever has never seen it will see the most recognizable emergency signal in history.
This care is consistent with the rest of the product. Lanterna BLA has no disco strobe mode, no simulated UV light mode, no police mode with blue and red flashing. It has six situations curated for nighttime routine, five of them for calm (Late-night bathroom, Don’t wake anyone, Looking for something, Dark room, Emergency) and one for real emergency (SOS). When the app says SOS, it is SOS. When the app says emergency, it is light at maximum, without decoration. The literalness is part of the editorial project.
In a real situation, the detail can matter. A hiker who got lost on a trail, a small plane pilot with radio failure signaling to the search team with the iPhone light, someone trapped under a car at night. In all those cases, a recognizable SOS signal can make a real difference between being seen and not being seen. In non real situations, the Morse SOS still has a function. It teaches. Whoever learns that SOS is three short, three long, three short, takes that knowledge for life. It is a code more than one hundred and fifteen years old that still works because it is simple and robust.
To turn on the SOS in Lanterna BLA, just open the app and tap the SOS preset. The rear LED starts blinking immediately, the screen turns on in discreet red. Tap again, the blinking stops. There is a timer to turn off on its own after thirty seconds, one minute, two or five. There is a widget to activate at once, without onboarding. It is a feature no one wants to need, but that exists for when you do. It turns on fast. And it blinks right.
