New and old glasses - obvious difference in bulk mass

[diant]

These interesting screenshots will allow you to see, at first glance, the obvious difference between old Schott glasses (when a flints were cooked with Lead and Arsenic) and new ones (cooking with Titanium and Antimony).

 

1. BK7 - old classic crown glass with exceptional UV transparency.

2. LF5 - old classic light flint glass with beautiful UV transparency for a flint-glass (35% lead oxide)

3. N-F2 - modern flint glass with TiO2 and Sb2O3.

 

All video is here.

 

 

 

[colinbm]

I don't think I'll be in a hurry to adopt the new N-F2.

[Stefano]

A rule of thumb is that if something already looks yellow in visible light, it is very likely to have a poor UV transmission. You can’t be 100% sure, but most of the times this is true.