Full bleed images/videos to fit height

Hi, this is more of a general question as it comes up for me time and time again. Is there any way to make Squarespace fit the height or width of an image to the section when used full bleed? I've tried both the following CSS:
 

@media screen and (min-width:767px)
{.homepage #page section:first-child { min-height: unset; height: 500px;}}

section[data-section-id="62b4162983d8ee6bc8a27cab"]
{
    min-height: unset !important;
    height: 500px !important;}

and it does change the height of the section correctly, but the image just gets made bigger so still crops it off. 

If anyone can help I'll be eternally grateful! 

Hi. Can you share link to page where you have problem? We can check easier

Hi - I think I've found a workaround for now by adding it as a section below and putting it in there. But as I said in the original post, it's an issue that happens all the time on all different sites. 

Thank you though. I just wish squarespace could add a 'fit to width' (or height) control