Auto screen numbers

[Furry Freak]

Guys - I have searched but can't find an answer to this one but it may have been covered.

Today, I learned that there are 3 numbers relating to auto screens. On the unit you'll find X.X.X These numbers go from 1 to 3 with 1 being the 'best'. I was looking at a very nice new lid which was 1.1.1. Got back, looked at mine to find that it was 1.3.2.

BUT and here's the question. What do the numbers relate to? Reaction time, optical clarity, atomic radiation reduction? It's great knowing that there is a scale, but maddening that I don't know how to interpret it.

I get the darkness scale 9-13: gas welding, brazing, solar eclipse etc. That's not it.

Sorry if it's been done, but I can't find it.

FF

 

[hotrodder]

To do with optical class and other things i don't understand

My 9002x is 1/1/2/2 FWIW

 

[marceleitor]

mine is an optrel 680

1/1/1/2

optical class / scattered light / homogeneity / angular dependence

 

[Furry Freak]

Thanks Guys. A little surprised at the lack of information available on this one. I followed the first link and actually got different criteria for the 4 categories.

I guess that looking simply, the higher the number the better the screen. Makes sense, sure. But if you can't afford the top model and there is a 1121 or a 1112 or a 1211 - well you get the idea, which do you go for? If any one does find an actual explanation of the ranges that have come up so far, please do let me know. I would like to try a top line screen to see how big a difference there is between my budget lens and super dooper one.

Thanks for the responses chaps. We're off and running at least.

FF