Resize gallery slideshow images to stretch full-screen and bleed on object-fit: contain mode.

Could you please help me with the following. On our website, there is an intro slideshow gallery which hosts different images of different sizes, which are customised with different text on top of them (from prior step on photoshop). Because when switching to the mobile versione the default "cover" setting messes up the aspect ratio wherein you can't read what's written on them properly anymore. Same goes for when you access the website from a computer with a larger or smaller screen.

To fix this issue, I did the following and shifted everything to "contain" ->

.gallery-fullscreen-slideshow-item img {object-fit: contain !important;

The problem now is that the different sizes of the images are creating a new problem, wherein some images appear very small (because of their cinematic ultra-wide aspect ratio), while other one's fit quite poorly (much like instagram squares). Is there a fix to this issue, or is it the case that when switching to "contain" I have to format all my images accordingly prior to putting them up on the gallery. 

Here is the website -> https://sajamafilms.com/home

Please help if you have a spare minute. Thanks!

Best it to format images I'd say. All other options are much more complex 🙂

Thanks, was hoping there could be an easier way, I guess it's going back to photoshop time.