I have the EFS 18-55mm lens i bought along with my 1100d. Will the live autofocus while recording still work on the 80d? because im debating whether to save the few hundred dollars and use that lens instead of buying a new one. i will be using the 80d for video recording, for the main feature of the live autofocus. like while recording it automatically focuses on either a face or subject in the middle of the screen. i dont know the real name. but please reply if you whether the 1100d lens works with the 80d
"Will the live autofocus while recording [video] still work with the 80D?"
The full model number of your Canon lens should be on the barrel, or on the front of the lens. If your 18-55m lens came in a camera kit with an EOS 1100D, then I think it is highly doubtful that it will function with the advanced video focusing features of the 80D, although the camera will likely try its' best to make it work.
You did not post the full model number of the lens that you are questioning. But, I have strong suspicions that the answer to your question is a definitive "no". You will need one of the more recent releases of lenses that have model numbers that end with "STM".
Your current 18-55mm lens will work just fine for stills with the photo, but the newer "STM" lens offers significantly better image quality, and far faster focusing. It is in the area of focusing speed is where your current lens will likely fall short of the mark when it owes to real time focusing when shooting video.
If you shop around, and wait for a sale, you should should find an EOS 80D camera kit with the latest "STM" version of the EF-S 18-55mm f/3.5-5.6 IS STM lens for an asking price where the lens is practically a free giveaway.