Broadcast NTSC TV used 440 for broadcast while NTSC Laser Disc had 565. In practical usage, broadcast was about 400 and Laser Disc about 500.
I have about 600 Laser Discs. I bought out a rental company when they went out of business.
Have you had any problems with laser rot? I only had two discs that started showing signs, but I haven't had a laser disc in seven years.
BTW, has anyone noticed that I can't make up my mind between "disk" and "disc?" 8^>