"large" vs. "full-size" images for slider

Is there any filter available to use “large” size images instead of full size for the slider? Full size images can be huge and very slow loading. Large size is much more suitable for most situations where an enlarged image is used.

Second q: how to override the default “large” size? WP Media settings have max height/width 1024px but “large” images are coming out max 720px, which is too small. I want 1024px.