By Steve Harris, Technical Support Specialist
If there was a single magic bullet that solved all your issues with LED on camera, and I had invented it, then I’d be a very rich man indeed. Sadly there isn’t, however here are a few quick tips and tools at your disposal in our Tessera software that when used together can make your screen look great and help to minimise unsightly moiré.
I’m going to talk about a couple of the most helpful things you can do to improve the look of your screen – it’s not exhaustive (if it were, this blog post would turn into a detailed paperback novel), so if you find you’re still having trouble, definitely drop us a line any time and we can help.
Moiré happens because your LED panels are made up of a tight grid of individual LED pixels. The sensor that captures the image in a digital camera also works on a grid system, using an array of millions of tiny light cavities, or “photosites”. They will never be in perfect alignment with each other (see left), and the clash of the two causes moiré.
The first tool in your toolbox is actually a very simple tip for setup: make sure your cameras are focused on an object that’s at least two metres in front of your LED wall. This causes the background to blur just enough that the camera will capture the entire screen rather than trying to focus on individual LED pixels.
Another very useful tool to avoid scan lines is to genlock everything together. All of our Tessera LED processors can have their refresh rate genlocked to your camera’s shutter rate, so that as the camera is capturing a frame of your video, the processor is drawing the same frame at the same time, offering a much smoother and cleaner filmed image
Lastly, make use of the phase offset within the genlock settings in our Tessera software, and just knock the value up or down to see how things improve. A quick tip – if you click on the button once you can then adjust the values by one with the up and down arrow keys on your keyboard.
Using these simple tips and tools together can often eliminate moiré and scan lines, with the processor and camera working in sync to help you capture a great looking image on your LED screen. Give them a try the next time you’re filming in front of LED.