1600×300 px images as post image on No sidebar, full with layout

Dear Support-Team, is there a way to display images with 1600x300 px as a post or page image „Beitragsbild“ when setting sidebar layout to “No sidebar, full with”? As of now using larger than 800 px wide images as post or page image „Beitragsbild“ are displayed with 800 px which doesn’t fit well to “No sidebar, full with” layout. Thanks for your help and best regards Ulrich This is for: Für das Leben in den Meeren • Deutsche Stiftung Meeresschutz (stiftung-meeresschutz.org)