Shopify image banner blurry?

have you also deposited it in a proper AUf solution? at least 5000px wide?
Of course, you need a good reserve because the banners are scaled freely in Shopify (or depending on which theme or app you use for your banner) and there it is always better when scaled from neatly much resolution to less. However, I also know that it can always be harder on individual computers/screens, e.g. on my MacBook Air I also have unsharp pictures, while the ones are sharply displayed on others