Greetings, Chocaluvr
Congratulations on your purchase of the EOS Rebel T7 camera. The camera is great for recording videos and it's able to record at Full HD of 1080p. In case the video is not in focus then it may be due to not focusing on our subject prior to recording video. This camera model does not include Movie Servo AF which means that it's unable to keep constant focus on a moving subject.
Prior to starting to record, line up your subject and press and hold down the shutter button halfway. The lens will attempt to focus on the subject and provide a confirmation when it achieves focus. You may then begin to record video. Please note that if the subject moves then please try to move as well to keep the same distance between you and the subject. This will try to keep the subject in focus.
Another option is to set the lens to manual focus instead of auto focus. Moving the switch on the lens to MF will allow for you to rotate and turn the focus ring that is towards the front of the lens. While recording, if the subject moves or you move from where you're standing then you can slowly rotate the focus ring until the subject becomes sharp again.
If you are already doing the above and the video still looks blurry then lets check to see if there are any lens filters or lens adapters attached to the front of your lens. For example, there are certain macro lens adapters that are available on the market that can screw on to the front of the lens. This is useful for macro photography for taking pictures of subjects that are close to the lens but the lens will have trouble focusing on anything that is farther than a few inches away from the camera.
