I am working on a project using Esri's Cascade Story Map app.
Within this, I am embedding web maps made using ArcGIS online. In these maps, I am trying to depict the continent of Africa, however none of the default zoom-levels in ArcGIS online are at a scale I want to use. Either they are too zoomed out, or too zoomed in. What I would like is an extent somewhere between the 3rd and 4th default zoom-levels.
Is there a way to set a custom scale to display my map at?
I have already tried changing the base map to a custom tile layer from Mapbox, however it seems that this did nothing to affect what zoom-level I can show.
Best Answer
Mapbox will not do what you would like, since it tiles on the same level scheme as ArcGIS Online, which itself uses the de-facto scale levels set out by Google/Bing.
The only way to achieve what you want is to publish your own cached service, on your own zoom level scheme, and modify the webmaps to use your custom basemap as the webmap's basemap. ArcGIS Online will then happily zoom at the required scale level (between the 3rd and 4th)
As of writing this there are no real ways of doing this with ArcGIS Online basemaps. I do believe there is a way of using the Vector Tyle services in custom GIS apps in a manner that might do what you require, but as far as I know ArcGIS Online is not vector-tile compatible, yet.