While the equipment discussed this month is not required to produce your own videos, it can be really helpful! An on-camera monitor can provide a larger version of you see through the viewfinder or on your small LCD monitor on the camera. Not everyone has super good eyesight like me, so having a larger image to use for critical focus, framing, reviewing audio levels, using focus assistance tools like false color and/or peaking can make your life much, much easier.
Monitors range in size from 5" all the way up to 10"; however, it is important to understand that 5" or 7" is about as large as you want to put onto your camera for a number of reasons: 1) Budget: the larger the monitor, the higher the cost
2) Mobility: the larger the monitor, the harder it is to move around
3) Logistics: if you need to move the camera, you have to move the monitor because they are tethered
Alternatively, if your camera can output an HD signal via HDMI, you can always connect your camera to a TV, as well! However, it can be very distracting to have a large image of yourself that you can see because it will naturally draw your eye away from looking into the lens, so be wary of that!