The Sony G Master Lens Lineup are the best offerings that Sony makes. If you're a Canon user, think of this as L glass. Sony goes out of their way to be clinically perfect, and it comes through in these lenses.
Before I go on, you should know that I'm not at all saying that lenses from these manufacturers are bad at all. Just go to DXOMark and take a look at their scores: Sony is very high up there and Canon is highly rated with their zoom lenses.
On a particularly snowy New York City day last week, Sony debuted their latest Full Frame E Mount lens in a top secret media briefing: the Sony 135mm f1. 8 G Master FE. The Sony 135mm f1. 8 G Master FE is the 31st lens overall in Sony's first party Full Frame E Mount lens lineup, and the 9th one to join the elite ranks of Sony's Premium G Master line.
I was obviously miffed the Sony FE 35mm f/1. 4 ZA was not the most appropriate lens to fully demonstrate the Sony A7R Mark III, on my last post. So much was my disappointment, that it drove me over the edge.