Yes, your images have to be “magnified” if you want them to be full width (100% browser width).
You’ve set their dimensions to 1170x700px, and the slider’s height to 700px. If you increase the slider’s height, the images will be less magnified on desktop and laptop screens, but will not look good on smaller devices, e.g. portrait tablets.
To turn off the full width image feature, set the
fullWidth: "on", property to “off”.