I am trying to obtain the acquisition date for an image form the standard imagery basemap from ArcGis Online. This image service consists of multiple 'sub-layers' for different zoom levels, and these 'sub-layers' may have been acquired at different times. For example levels 14-17 may be from 2015 and 18 from 2011. I don't see how to get the zoom level directly, but using the scale factor and the tool from https://developers.arcgis.com/documentation/mapping-apis-and-services/reference/zoom-levels-and-scal... I can get a scale factor assigned with a zoom level. What I need is the converse of that: given some arbitrary scale factor, what zoom level is used?
Zoom level 17 is associated with scale factor 4513.988705
Zoom level 18 is associated with scale factor 2256.994353
However I've found that with scale factor 1:3209, the image returned is from zoom level 18; with scale factor 1:3210, the image returned is from zoom level 17, the the break is somewhere in between the 2 (but not exactly halfway).
Any information on how to precisely determine the zoom level for any given scale would be greatly appreciated.
