Slight Blur over entire Gallery

Hello and good day everyone,

Any idea how can I add blur over the images in my gallery, just as this photographer does on his site?

My site: https://nouellin.com/

His: https://josselin.de/blog/constellations/

Thank you!

I don't think that website has any blur effect added, I think the image are just "low-fi". If you want blury images you can certainly do that with Custom CSS:

collection-type-gallery .thumb-list .thumb img {
    filter: blur(1px);
    transition:ease-in-out 200ms;
    &:hover {
      filter: blur(0px);
  }
}

and even lose the blur on hover...