This is just for curiosity's sake, and my Google skills are failing me with this, so I thought I'd ask here. I was wondering if anyone had any info about the coatings Nikon used prior to the introduction of NIC in '74 (if my research is correct). My reason for asking is that whilst gazing lovingly at my camera collection (just kidding, I was bored while feeding the baby) I noticed a bit of a trend in the colors of light reflected by the front elements. It's my understanding that this is because of the lens coatings. If this is incorrect, please feel free to enlighten me. Anyway my three oldest lenses, as best I can tell from Roland Vink's site (50/1.4 S, 35/3.8 S, and 105/2.5 P), all have reflections with a yellow/orange tint (see picture below).The next two in age (28/3.5 H, and 50/2 H) both have a purple-ish tint. It seems that there was a change of some sort in the mid 60's. Another bit of curiosity,my AI lenses (all of which should have NIC) all reflect light with the same blue/green tint, with the exception of my 50/1.4 which appears more similar to the yellow/orange of the oldest lenses. This seems at odds with my readings that say all AI lenses and later got the NIC coatings untill 2000 when they came out with SIC. Like I said before, this is just for curiosity's sake. I'm not sitting here obsessing about which is better than the other or anything. Slow news day I guess.