I'm developing a web application that already use a responsive design(bootstrap) and play well within any small resolution. But that's common that nowadays desktop screens go up to 1920px wide, and they are our main audience for now (it's a web app for IT professionals).
Most of our pages are forms that have some logical order of input and we are going to prefer a top-down reading and distribute they vertically. So, there's the problem, we need to use more height than width, leaving even more unused space in the screen.
The product owners already complained about the blank space on the left but it seems that distributing the form fields horizontally isn't a option as you can see in my draft below:
The scale in this draft isn't much right, a 1920px wide screen leave much more blank space on the left, making inputs far away from each other in the 2nd approach.
I need to choose between leave a blank space on wide screens or leave related inputs far away from each other. IMHO the #1 approach (see the pic) it's better, but I would be glad if your guys point out if it's truly the best solution, so I can convince the product owners that is better this way or another.
Based on the DA01's answer I've updated my draft following his considerations.
About centering the content, I think this could conflict with the sidebar concept so I modified it's behavior. Before, the sidebar could be toggled from a button and the screen corner(swipe), now it's just getting hidden on small devices and the button for toggle appears on the screen as well the swipe gesture get's enabled.
It's much more cleaner now, but I'm not sure what's the ideal sidebar behavior for this setup...