Wide Image Inside Posts for Full width posts

Hello,
I want to include images as full width like this post https://scroll.in/field/994574/pause-rewind-play-the-2011-england-series-when-rahul-the-wall-dravid-stood-so-tall

I want image inside post not as featured post.

The problem is, my container is narrow (800Px) and the image can’t stretch beyond that.

I’m using fullwidth without sidebar.

Also, I’m using canvas plugin to create widescreen image.