I sampled a pair of Zen-Ray summit 10x42 binoculars, which also has dielectric prism coating. To my eyes, it is noticeably brighter than the non-dielectric old Monarch binoculars. Is it due to dielectric or overall optical improvement?
The new ZRS ia a new design from the older ones, so I think the answer to your question is ...both. Coatings in general are getting better too. I would concur that my new ZRS is better than my old Monarch.
