Yes. This is what Apple says at http://www.apple.com/iphone/built-in-apps/ : "Shoot 8-megapixel photos and 1080p HD video with the iSight camera."
So just use that built-in app.
Didn't your iPhone 5 come with a user manual? Then better download http://manuals.info.apple.com/en/iphone_user_guide.pdf and start reading the full 156 pages!
Can I make a video with iPhone5