Tumblr theme vertical photos Options

[photog35]

Hi guys,
I am needing some help in adjusting a tumblr theme for my photography blog. (I have no knowledge in html or css).
I would like to make the vertical photos on my blog have a smaller width than the width of the horizontal photos. Right now, the vertical photos have the same width as the horizontal photos (which makes the vertical photos look really big compared to horizontal photos). Is there a way to change that?

Here is the free theme I am using: https://otherthemes.com/themes#centre
(Their theme support isn't available anymore, which is why I am asking for help here).

Thanks for your help!

[Brian Chandler]

I doubt if anyone here knows much about Tumblr: the whole point of these services is that they make money, and you join up to their way of doing things, which isolates you from things like HTML and CSS. So the chances are that it is extremely difficult to adjust basic bits of the html files produced.

[pandy]

Sound very complicated. Tumblr, or its template engine, would need a way to know what photos have horizontal orientation and what photos have vertical orientation. That's probably possible for a server side language to find out even if it would be hit and miss sometimes (since the orientation thing in images is wonky). Or it could just find out if the image width is larger or smaller than its height. But to tell Tumblr to do that... No, not likely.