Understand your user needs and content
Although we’re in the Brave New World of ultra high resolutions, 4K is often neither necessary nor even desirable. For 4K can lead presenters to show content too small even for the closest viewer, let alone the farthest!
So what resolution is required? Again, the DISCAS standard gives precise guidance here - and also the font size needed so viewers at the back of the room can read as well as the closest.
For most presentation, meeting or teaching applications, then HD (either 1920 x 1080 pixel resolution, which is 16:9 aspect ratio, or 1920 x 1200, which is 16:10 aspect ratio) is perfect. It’s only in cases where top quality video or high definition images, such as medical, detailed engineering, oil exploration etc that the real need for 4K arises.
Even if your display is true 4K, it doesn’t mean your image is 4K. Cliché alert: any system is only as good as its weakest link. If, for example, your computer or video source (or any part of the system) is only HD, then that’s all your display can show; a single pixel detail in HD becomes a four pixel block on your fancy 4K screen. 4K is only true 4K when every link in the chain from source to display is true 4K.
In practice 4K and UHD are interchangeably used terms. The strict definition is that 4K resolution is 4096 x 2160 and UHD is 3840 x 2160. UHD is exactly 4 times the resolution of HD - twice the width of HD (1920 x 2 = 3840 pixels wide) and twice the height (1080 x 2 = 2160 pixels high). So UHD is usually what’s needed in our ProAV world.
Is it big enough?
What image quality is all about.
Is it too bright? Don’t design in eye-strain.
Can you see me at the back?
Design in your viewers’ comfort and the ability to concentrate.
Inspect what you expect.