Here are the recommended sizes and tips for adding images to your Cause pages!
Individual Cause Headers:
Recommended images are ones that are 1440px x 760px with the important imagery near the top 400px. Most of the image will be shown, but as it scales, it will mask from the top.
Cause Index Header Image:
Recommended images are ones that are 1440px x 760px, keeping all text within the vertically centered 250px. Only the middle 300px will be visible, but depending on the width of the browser, more or less of the height will be shown.