I was looking at this photo

https://i0.wp.com/railco...10.jpg?resize=1215%2C759

and wondering what exactly the text on the LED display says…

"If the train is coming towards you and you can read this, get out of the way"?

Regards

Mike C

Two modern technologies at play here that make life difficult.

The human eye sees it perfectly.. but:
1) The LED message boards are displaying content in a multiplexed manner - that is the LEDs/segments of the display are not all on all the time, but are flashed at some interval. Like the 24 frames per second of motion picture projection, the human eye/brain cannot perceive that flashing and it looks like its a solid ON image that may scroll and look fine. To things that can take a quick image, like a fast camera, you can grab an instant of that and that won't look like what the human brain sees/interprets. Even a fast film camera could grab such an image state.

2) Modern digital cameras - they use rolling shutters to grab the frame. So the entire grid of pixels isn't captured and stored as a single image, then the next image (frame) is grabbed such that each frame is a new full image of what things look like, say 1/60th of a second later. The frame is captured by grabbing one row of pixels at a time, storing that, then grabbing the next row of pixels and storing that, and so on down the full height of the image.... so when the last row of pixels in the frame is captured and stored, some amount of time has passed since the first row of pixels in the frame was captured and stored, and between those two captures the subject will have moved or changed in some small way. If that change happens fast, such as flashing LEDs at high frequency, then that difference between the rows of the single frame can also be seen as an image artifact.

So when you look at video of modern cars with LED head/tail lights they blink annoyingly on the video replay, and such displays can be illegible in the playback. Compensating in the recording settings/equipment can solve that but usually folks don't do it.

Now to what the actual message says in the image, thats anyone's guess. But my guess is the locomotive designation for those rail lines that need it for the optical detection, since I don't see a loco number on the front of it otherwise, unless thats what those tiny letters near the left side say.





But it could be a city or route number, depending on where the train runs, such as this usage on another type of locomotive here in Seattle:

Nope. My digital cameras from Olympus and Canon still have a shutter sound when I turn the sounds all off.
There is no sound when taking photos with my camcorder or smartphone - those do not have a physical shutter.

It is possible to have digital cameras that still use a physical mirror to direct the lens image to a viewfinder and the move out of the way when the capture button is pressed thus making a mechanical sound. Most digital cameras do make the sound artificially as there are no moving physical parts. In some regions of the world there is a legal requirement that the camera make a sound, to ensure people nearby know there is a picture being taken, I suspect.