The "issue" is dependent only on the photographer and you, and not the site. Dave can't stretch a banner to accommodate all the different pixel width viewing that member use without also increasing the height (unless you would prefer image distortion). The banner contributor chose to upload that banner at a 1215 pixel width that does not fill the width of your screen. (Remember you previously decided not to use the 1600 px option. (See your previous post.) The fact that there is such an abrupt change at the split is due to the composition of the photo itself (starting with orange and ending in black). Both issues can only be mitigated by the original photographer.
So unless you want to give some pointers to the banner contributors, yes, just train your eyes to stop at the split (or view on your laptop with the smaller screen).
