What! You fried an egg on your ground glass?

Borosilicate Ground Glass with Cooked Egg --Not Recommended!

This demonstrates that borosilicate glass really is tougher than ordinary glass.  It is made of the same stuff as Pyrex products.  Like Pyrex, borosilicte glass can break, but it can take a lot more abuse than ordinary glass.  The GG shown is a 4×5 borosilicate  screen.  The egg was cooked on medium heat.  The screen never cracked or shattered, but the fried egg became permanent rendering the screen useless   –so don’t try this at home!

Hopf Ground Glass Focusing Screens are all handcrafted and Made in the USA.

Why use Hopf Ground Glass?

Hopf ground glass is hand ground to perfection using a grit compound designed for optimal diffusion and “brightness”.

A Hopf ground glass focusing screen provides the brightest image view with good contrast and detail in both highlights and shadows.

Your focusing screen is the interface between the image and your camera. It is an integral part. Like a lense or shutter, the focusing screen is essential and the camera system is usless without it.

It only makes sense to use the best and brightest for easy viewing and razor sharp focusing.