It's easy. Any Sinar glass of the same format will be interchangeable. In fact, I don't recommend the very early Norma glass because it had a coating which made it dimmer, rather than being actually ground like later glass.
It's easy. Any Sinar glass of the same format will be interchangeable. In fact, I don't recommend the very early Norma glass because it had a coating which made it dimmer, rather than being actually ground like later glass.