Theoretically the larger diameter objective scope should be brighter. How much? Well there is a theoretical number based on the increase in light gatheringsurface area and then there is the actual number based on the quality of the glass, number and quality of coatings, etc...

Again, I am at a loss with hard factual data to support one or the other. However, I did see some light transmission tests for the Meopta bins in comparison with the upper end Swaro, Zeiss and Leica. The Zeiss FLs had the highest light transmission numbers (93%) with the Leica Ultravids in second at 87%. The Swaro ELs and Meostars were next at 86% and then the Leica Trinovids were around 82%.

I do not know if that helps any but I thought I would mention it.