Wait Time Photography

[Doodlyday]

I notice that when the digital wait time boards are photographed or videotaped, the dots on the board scramble for the photo or video. Does anyone have an explanation for this?

 

[fractal]

I notice that when the digital wait time boards are photographed or videotaped, the dots on the board scramble for the photo or video. Does anyone have an explanation for this?

I believe it has to do with the vibration of the light on the board (refresh rate) and how it's captured by your camera's sensor.

http://www.signindustry.com/tips/tips/2014-11-06-Photographing_LED_Displays_Successfully.php3


The first thing to try is setting the camera to Shutter Priority Mode, commonly denoted as “Tv” or “S” on the camera’s dial. This will automatically compensate the ISO and aperture to get a good exposure. That way you only have to adjust one setting. If Shutter Priority Mode doesn’t get the results you want, the next step is to try full Manual Mode. Just turn the dial a few more clicks to the “M” position. Don’t worry, it’s not as scary as it seems. Take some time to familiarize yourself with your camera though with these helpful hints:

1. 
   
   • Slower shutter speed. The most critical step is to lower your shutter speed to 1/15s, 1/30s, 1/60s or possibly 1/125s. These speeds help mimic the sign’s refresh rate and better ensure that you don’t see “tiling” or lines across your photos as the modules refresh. Keep in mind that the lower the shutter speed, the steadier the camera will need to be to prevent blurry images. The general rule is that if you’re shooting any photo with a shutter speed below 1/60s you should use a tripod or prop the camera on a steady surface like a wall or the roof of your car.
     Why does the shutter speed matter? LED signs, much like older TV screens or computer monitors, often show bars or lines in photos because the image is constantly refreshing. Slowing down the shutter speed fixes this problem by giving the modules time to get in sync.
   • Lower the ISO. Once you’ve changed the shutter speed, you may also need to change the ISO, which adjusts your camera’s sensitivity to light. Allowing the shutter to stay open longer lets more light into the camera so you’ll often get blown out photos, especially on bright sunny days. One way to prevent this is to set your camera’s ISO setting as low as it will go, typically 100. You can increase the ISO when not in direct sunlight but rarely should you go above 400 when shooting outdoors. Low ISO levels will also produce the cleanest images with minimal digital noise. If using Shutter Priority Mode, this should be adjusted for you automatically.
   • Adjust the f-stop. Similar to shutter speed, your camera’s aperture setting, or f-stop, controls how much light can reach the image sensor inside the camera. When you’re using a lower shutter speed, you’ll likely need to increase the f-stop to prevent washed out, overexposed photos. I recommend using the highest f-stop number available on your camera (typically f/16 to f/22). The higher the f-stop number, also known as a narrow or small aperture, the less light allowed in. This compensates for the slow shutter speed we’re using, which lets a lot of light in, and makes for a better overall exposure. This should also be adjusted for you automatically if using Shutter Priority Mode.

 

[Doodlyday]

Interesting. Thank you!

 

[thomas998]

Interesting. Thank you!

Previous poster is right. Try taking a photo of you flat screen TV in shutter priority mode and then adjust the speed up and down and you'll see a similar type issue taking photos of your TV... Only difference is that the TV scan rate is very uniform so you'll generally see bands where nothing shows up at too fast a speed, what you describe sounds like the times aren't as uniform... but its the same thing the output if flickering at a high enough rate you don't notice it but at a fast speed on your camera you're catching some lights on when others are off even though from your eyes you see all of them on.

 

[PhotoDave219]

Same deal as really poor gym/sports lighting. You'll notice in really bad HS gyms, the lights flicker between different different color balances, which sucks.

The solution is simply to slow the shutter speed down. 1/60th should do the trick for the tip board.