Slider not responsive and Header is wrong size

I start losing parts of my header when I shrink the window; it breaks at 1500 – as it gets smaller I lose more of the image!

– ALSO –

I have placed a header that is 1600px x 200px per the instructions on the page: theme recommends a header size of 1600 × 200 pixels.

Well on my desktop monitor a good chuck of it is missing on the right side. My monitor is 1900px wide.

Now if I minimize the window the header shrinks, and at 1600px it is perfect! So I think you need to update your instructions