Compensation effect of intensity change induced by differential seeing: the area sampled by the black rays is expanded in the image plane, distributing the light over a larger area and thus reducing the flux, but this is compensated for by a corresponding increase in the area of the wavefront that is collected by the telescope at the height of the seeing layer.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.