B&w console front glass

[timmy]

Does anyone know why the safety glass on the front of an old b&w tv is so dark, is it to shield from radiation ? It overall darkens the brightness of the picture it's like it defeats a nice bright picture output.

[Tom9589]

Maybe it needs cleaning.

[timmy]

It's tinted from factory.

[Electronic M]

Some are dirty from dust others are tinted on purpose.

Purpose tinted safety glass is to prevent glare from room lighting. Glare reflected off the CRT face is attenuates twice as much (coming in through the tinted safety glass and leaving through it) as the CRT image light... But what about the light reflected directly off the outside of the safety glass it's self you ask.... usually the safety glass is tilted down so reflections off the safety are aimed at the floor and not up at the viewer and or the glass is frosted to reduce reflectivity.

[Notimetolooz]

The glass is tinted to make the blacks blacker and improve the contrast.
The unlit phosphor is not very dark, so room light makes it show brighter than ideal.

[Tom9589]

I remember one B&W manufacturer (Hoffman?) which had a yellowish tint to its safety glass kind of like those "night vision" glasses they sell on late night TV shows.

What was behind this unusual tint? Was it really easier on the eyes?

[Electronic M]

Originally Posted by Tom9589

I remember one B&W manufacturer (Hoffman?) which had a yellowish tint to its safety glass kind of like those "night vision" glasses they sell on late night TV shows.

What was behind this unusual tint? Was it really easier on the eyes?

Hoffman (Qu)Easyvision was just marketing Tom Sawyering the public to think the cheap green war surplus glass manufacturing was saving on was somehow a feature....It didn't offer any real improvement or detriment just was something different.

[old_tv_nut]

There are some posts around here somewhere that say the urban legend is that Hoffman got a deal on some war surplus tinted glass.

The tinted sets were marketed as "Easy Vision."

[timmy]

Well I'm just going to get a clear sheet of glass cut to size and call it done.

[Tom9589]

I don't think I would just get ordinary glass. The safety glass is there to protect you from flying glass should the CRT implode. Supposedly, the electron gun can come at you at a high rate of speed if the CRT implodes in a certain manner.

[bgadow]

Hoffman notwithstanding, all the manufacturers had to pay extra for that tint so it must have done a good job. In the color era, when brightness was paramount, the higher end tubes had tinted faceplates and even frosted.

[old_tv_nut]

Originally Posted by Tom9589

I don't think I would just get ordinary glass. The safety glass is there to protect you from flying glass should the CRT implode. Supposedly, the electron gun can come at you at a high rate of speed if the CRT implodes in a certain manner.

I think the separate safety glass is more to break the impact and prevent implosion than to protect you if it does implode. This means that high strength glass is still desired over ordinary window glass.

[MadMan]

Tempered glass would be preferable. If you find an old coffee table top, you could probably find somebody to cut it to size. I suppose the easiest route would be to get a piece of 3/8" thick plexiglass, or however thick the original glass is. Matter of fact, in lieu of tempered glass, a sheet of thick plexiglass with a sheet of 1/8" regular plate glass in front of it would protect the tube from impacts and protect the plexiglass from getting scratched.

Also I don't think Hoffman Easyvision sets were actually green phosphor. Just yellow safety glass.

[JohnCT]

Originally Posted by Notimetolooz

The glass is tinted to make the blacks blacker and improve the contrast.
The unlit phosphor is not very dark, so room light makes it show brighter than ideal.

When we were kids, we used to watch TV in the dark because the picture was so improved for that very reason. Of course, mom used to yell at us because "it will hurt your eyes!"..

Sylvania, somewhere about 1980 or so, came out with the Superset. These TVs had a very dark tinted faceplate and had a spectacular picture. These TVs had a beautiful black level. Unfortunately, in order to correct for low brightness, these tubes were driven hard and died early.

Side story: back in the early 70s, my dad used to buy RCA all-new Hi-Lite 23" and 25" tubes for CRT replacements, but also stocked a low end rebuilt tube named "Maverick".

The Mavericks were the economy line and dad used to give customers the option of price. The Maverick's were bright, sharp, and reliable and had excellent purity, but they had the oddest light colored phosphor - sort of a greenish white. I mean, when the TV was off it looked weird. Back then, I couldn't understand why they picture was odd. No matter what I did with the contrast or brightness, I couldn't get a normal picture. Of course, it was the light colored phosphor. It didn't occur to me at that time that the darkest image on the screen couldn't get darker than the unlit light color phosphor.

John

[Yamamaya42]

Originally Posted by JohnCT

When we were kids, we used to watch TV in the dark because the picture was so improved for that very reason. Of course, mom used to yell at us because "it will hurt your eyes!"..


John

Can't resist!

https://coub.com/view/4q8to