Interesting for newby’s but fairly basic info for old timers. Very much crafted toward movie making than stills, although the applications are close for both disciplines. For 35mm full frame (I also shoot 35mm half frame.) I find the 50mm lens is where I start, then go from there to other focal lengths. Back in the early 70’s I could barely afford a body with the standard 50, so for a year it’s all I had.