Bedford: Customize the height of the banner image?

I am completely clueless when it come to coding and need help! I'm using the bedford template. I'd like to shrink (or customize) the height of my banners - not just on the home page - to use images about 1280 x 400 instead of the current 1280 x 800. How do I do this?

Also- does that change where the description ends up? Do I have to add anything to keep it centered among the banner image?

And just to be clear, can you specify the parts of the code I would need to change if the image wasn't 400px height? (maybe make them bold so I can pick them out?)

**Bonus: Is there a way to customize the height of the header (nav bar) as well?

Thanks so much for the help!

Based on the solution here, this code should work:

.transparent-header.view-list .banner-thumbnail-wrapper,
.transparent-header.collection-type-page .banner-thumbnail-wrapper{
  padding: ##px 0px ##px;
}

Where you replace the ## with the sizing that works best for you.

This code appears to work for pages with banners provided by thumbnail images (not promoted Gallery Blocks).

Please note that the height of the banner is linked to the amount of content in it (added in the page description area of the page's settings).

More content will create a taller banner.

Does this code also work if you've turned off the transparent header?

This works well for transparent headers but what if you have a fixed header? Thanks!