Whatever your camera is, you probably have an App to turn your phone into a wireless monitor. Sony has Imaging Edge; Canon has Camera Connect; Fuji has Camera Remote; Panasonic has Lumix Sync and Nikon has Wireless Mobile Utility. What’s common to all those remote control apps is that they work over WiFi and display horrible Lag. That the lack of creativity in the apps’ names.
What if there was a cheap way to convert any Android phone into a wired, low latency, high brightness HDMI monitor? Youtuber Neon Airship shares how to accomplish that for about $20. It involves as little as a tiny capture card and an OTG cable. The good news, you already own the expensive monitor, it’s your phone.