new sort glass for protective front pane

[AgX]

Lately the standard UV filter as protective pane in front of the lens has got as alternative chemically hardened plain, colourless or even coloured glass.

Now a new substrate comes in use that is harder in itself: glass-ceramics.

Next year Sigma shall introduce glass-ceramic protective panes mounted in filter-thread rings

 

[Mick Fagan]

Would be a Schott Glass product in conjunction with Sigma?

Mick.

 

[AgX]

The protector will be completely made in Japan with glass-ceramic from Ohara glassworks.

Optical grade glass-ceramic is already offered. Though I did not yet know of a photographic application.