A:AnswerHello Tyler, according to Canon's specifications and support sites, the Canon Rebel t4i DSLR has an external microphone input that supplies plug in power. By that information, yes the VideoMicro would work for it.
A:AnswerI am using it for my Nikon D5200. As long as you have a 3.5 size plug under the plastic piece on the side of your camera it will work. Looks like a headphone size plug in. That is where I plug mine in.
A:AnswerIf you owned the A7III and knew how to use it or pretty much any mirrorless camera you would know and the various inputs. As long as the camera has a microphone input jack any mic will work. Also I would not recommend this mic with that camera. Spend a bit more to get better control over your sound quality.
A:AnswerAs long as it has a (standard)35mm headphone jack, beside you can always return if it doesn’t work. Bestbuy has a solid return/exchange policy.