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New S8612 equivalent?

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#1 dabateman

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Posted 26 June 2020 - 11:36

I just saw a listing for ZY83 glass. A Chinese version of S8612.

Has anyone tested it, or even seen it before. I wonder if its just another BG39 or if they have actually started to get S8612 correct.

Maybe more options in the future.

#2 colinbm

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Posted 26 June 2020 - 11:53

Something different...

#3 colinbm

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Posted 26 June 2020 - 11:58

Pretty wide off the mark.....
Posted Image

#4 dabateman

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Posted 26 June 2020 - 12:20

Thanks Colin.
I couldn't find any spectrum data for it.
Looks kind of like a BG62, 63, 64 type glass than.

#5 UlfW

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Posted 26 June 2020 - 12:43

View Postcolinbm, on 26 June 2020 - 11:58, said:

Pretty wide off the mark.....
Posted Image

I would not dismiss it that fast, even if the quality of the measurement here is really lousy.
It still might be worth investigating further. The data seams to be measured with a glass thickness of 0.3mm.
Thin glass is ideal for exploring the depth of the attenuation.

If I was to analyse a filter glass's transmission well, I would like one thin slice like this and one rather thick, >3mm.
Ulf Wilhelmson
Curious and trying to see the invisible.

#6 JMC

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Posted 26 June 2020 - 14:31

So, below 325nm it goes negative, and not by 0.1% or 'in the noise'. Based on this it's hard to draw any useful conclusions, other than the characterisation is a bit rubbish.

But assuming the data above 325nm means something. At 350nm it has 50% transmission at 0.3mm thick. Scale this up to 1.5mm, it would have 3% transmission at 350nm. At 365nm and 1.5mm thickness it would have about 24% transmission. Oh lordy, I hope my maths is right. Assuming it is, it doesn't really strike me as particular good for UV.
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#7 UlfW

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Posted 26 June 2020 - 14:40

Thanks Jonathan for calculating.

I was just reminded of my ideas how to analyse filter materials, when I saw the 0.3mm thickness.

It is too hot here for any meaningful brain activity.
I have 30°C indoors, 36°C outside the window, in the shade, but close to a sunlit wall. :blink:
Ulf Wilhelmson
Curious and trying to see the invisible.

#8 Stefano

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Posted 26 June 2020 - 15:32

View PostUlfW, on 26 June 2020 - 12:43, said:

If I was to analyse a filter glass's transmission well, I would like one thin slice like this and one rather thick, >3mm.
Agree. The thin filter will give you a precise measurement for the low transmission regions, and the thick one will do just the same for the high transmission regions. I hope one day that someone will be able to measure the green leak of Hoya U-340 glass, and you need a filter no more than 1 mm thick to do that.

#9 Cadmium

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Posted 26 June 2020 - 15:55

UV transmission can look good at 0.3mm.
However, there is quite a bit of lower UV transmission difference, not even as good as BG39.
I would use BG39 before I would use ZY83, and S8612 is much better than either BG39 or ZY83.
Even at 360nm BG39 and ZY83 fail to reach the transmission of S8612.
Now let's look at a little more realistic thickness, at 2mm thick (the most used, practical, and versatile thickness) there is a whopping 15% different between BG39 and S8612,
and you can bet the ZW83 2mm thick is going to be even more of a difference at 360nm.

Attached Image: Schott_S8612_Schott_BG39_and_China_ZY83_ALL_0p3mm_thick.jpg

At 0.3mm thickness.
Attached Image: S8612_vs_BG39_both_0p3mm_T_L.jpg

At the more realistic 2mm thickness.
Attached Image: Schott_S8612_2mm_vs_Schott_BG39_2mm_new.jpg

Edited by Cadmium, 26 June 2020 - 15:56.


#10 Andy Perrin

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Posted 26 June 2020 - 16:19

View PostJMC, on 26 June 2020 - 14:31, said:

So, below 325nm it goes negative, and not by 0.1% or 'in the noise'. Based on this it's hard to draw any useful conclusions, other than the characterisation is a bit rubbish.

But assuming the data above 325nm means something. At 350nm it has 50% transmission at 0.3mm thick. Scale this up to 1.5mm, it would have 3% transmission at 350nm. At 365nm and 1.5mm thickness it would have about 24% transmission. Oh lordy, I hope my maths is right. Assuming it is, it doesn't really strike me as particular good for UV.
I get the same values.

#11 Cadmium

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Posted 26 June 2020 - 17:50

Here is all three, overlay of ZY83 rough black line. All 0.3mm thick.

Attached Image: Schott_S8612_Schott_BG39_and_China_ZY83_ALL_0p3mm_thick_graph_overlay.jpg

#12 JMC

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Posted 26 June 2020 - 17:53

View PostAndy Perrin, on 26 June 2020 - 16:19, said:

I get the same values.
Cheers Andy.
Jonathan M. Crowther

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