I got the Canon EF to R Adapter with the drop-in variable ND filter a few months ago but never had a chance to test it until yesterday afternoon.  Headed out to South Perth in the afternoon to take a few shots of Perth City view using the Canon EOS R, the EF-R adapter with the var ND filter and the Canon EF 16-35mm f4 IS lens.

Majority of the shots were taken with about 20-30 seconds exposure… Am pretty happy with the var ND filter.  Didnt really use it at the max level as the colours were way off…