@Prof-Hafner

3 months ago

Hello world. The point of this video is to show how dark it gets, but also to get you thinking about your eyes. Your eyes are not linear sensors of light. Your pupils can open, the different types of photoreceptors (rods/cones) have different sensitivities, and of course your brain can manipulate its own interpretation of the image. When it is overcast and looks “a little darker” than a sunny day, the amount of light is actually much lower. A camera does similar tricks. It can brighten things up when it gets dark by adjusting the exposure time or the sensitivity of the CCD/CMOS detector. To get a more accurate look at the amount of light, I used the Filmic app to make this video. It is not a video but a timelapse with an image every 5 seconds. I set it to hold a constant exposure, which is why the image gets very dark when the sunlight goes away. To the eye, it did not really get that dark. It was not “pitch black” because our eyes adjusted. However, it was dark! It looked like a time late at night when the only light is a bright moon. Now the big question – why does the sign go out? You can see the bright light on top of the sign is constant (and a few lights in the distance and headlights are constant), but the red sign and orange letters seem to switch off. They actually don’t. If you watch it on a large enough screen you can see they are still illuminated. I think this was an effect in the camera (iPhone) that the app would not let me keep constant. Perhaps it switched to “night mode” and automatically applied some contrast adjustment. The video is not edited. I assure you I don’t care enough about my YT career to bother! 😊 If anyone is an expert on how the iPhone manipulates images and wants to explain what happened it would be great to know!

5 |