Dear all,
briefly said, my question is as follows: are there different zoom factors for openstreetmap vs. opentopomap?
Let me give some more details:
my observation is from application “brouter”.
“brouter” supports display of openstreet maps as well as of opentopo maps.
When using topo maps, and zooming into more details, at some zoom factor the topo maps just disappears. Only some grey background is shown.
When I switch to openstreet maps (note: both have the same zoom factor) I can still see the openstreet map, and can zoom even more into it. Now my question is: why is this happening?
My guess is, that openstreet maps are based on some vector graphic, while opentopo maps are kind of bitmaps, organized a tiles of map data, and the maps to just exist till a certain zoom factor.
It’s entirely possible for a server to serve different max zoom levels to different clients - you might see one thing from “brouter” and another thing from a different site accessing the same map tiles.
What each map style shows at a particular zoom level is decided by that map style, and as you’ve noticed, does mean that different things are shown at different zoom levels in different map tiles. Map styles also sometimes show “big things at lower zoom levels, and smaller things only as you zoom in”.
Finally, although all of the styles you mention are raster maps, it’s perhaps worth mentioning that vector zoom levels for most sorts of vector tiles are one different from raster zoom levels, so this vector zoom 15 map covers the same area as this raster zoom 16 one.