Hello, I'm brand new here. I have a GH4 to use for narrative filmmaking, and I am collecting vintage lenses to get a better film look. The fact that many vintage lenses are more affordable than modern doesn't hurt. I'd like to use a speed booster and then adapt the vintage lenses to that speed booster. For example, if I got a Canon FD to MFT speed booster, I would put FD adapters on the vintage lenses - standardizing them, so to speak. The question is, what is the most ubiquitous lens mount for this purpose? I know flange/focal plane distances are a factor, but after many hours combing the internet, I still don't have a clear idea about the best choice. (I'm also pleased to see that some folks here have managed to adapt fixed lenses. I have a Kowa SE and a couple Yashicas I wouldn't mind dissecting to get that nice glass onto my GH4.) Any thoughts are greatly appreciated!