Zoom in rendered maps

Hi guys!
I searced a lot in the forum, but i cant find anything about it. What it depends on that how big zoom can i use on my rendered map? So i mean that in this (https://web.archive.org/web/2020/http://www.minecraftworldmap.com/worlds/...8/max/0/0) map i can easily see flowers but in this (https://web.archive.org/web/2020/http://www.minecraftworldmap.com/worlds/...7/max/0/0) im happy to see the cactuses. So what can i do to make my map more zoomable? :) I hope i make myself clean, because its hard to explain a thing like this :DD

Zoom levels are automatically determined based on the size of the map. The bigger the map is then the less you can zoom in.

Shameless self plug: There is also a premium service that gives you unlimited zoom levels as well as other neat benefits. This also helps to cover the costs of running the site