With more USB ports, you are able to connect more devices.
Optoma UHD51A: 4
17. contrast ratio
Contrast ratio is the visual distance between the lightest and the darkest colors that may be reproduced on the display. A high contrast ratio is desired, resulting in richer dark colors and more distinctive color gradation.
Epson PowerLite Pro Cinema 6030UB: 600000:1
18. lamp life
This shows the lifespan of the light source. Beamers need to have their lamps (light source) replaced every now and then.
Vivitek Qumi Q7: 30000h
19. composite ports
The more composite ports a device has, the more devices can be simultaneously connected, such as video game consoles and set-top boxes.
NEC NC1200C: 4
20. has manual focus
This allows to manually set the focus.
71% have it
21. component ports
The more component ports a device has, the more devices can be simultaneously connected, such as video game consoles and set-top boxes.