Reduce height of header image

Howdy, I have uploaded an image to the media folder, sized 1632 x 200px. I have turned on set headers for the theme to 'Excluding Homepage, Page/Post Featured Image'. I have edited the page, selected a featured image, and set "Header Featured Image Options" to 'enabled'. The result is a header that is cropped in width and stretched in height. My questions: 1) Can I control the dimensions of the header on a per page/post basis? If so, where are those settings? 2) The theme header setting page says 'Your theme recommends dimensions of 1920 × 540 pixels.' for a .mpg header. Is this the same dimension for static headers? If so, how do I change that dimension? Regards, BJ