I'm looking for a translation

[colinbm]

Toni, et al, I think it would be better to use the makers designation for a filter, as the Schott & Chinese are very different filters & are not really equivalents.
Therefore the Schott & Chinese graphs will be different, Also the Chinese graphs are not accurate & the actual filter needs to be tested.
Then the actual graphs will be quite different.
What I an suggesting it that the graph above is not what Toni thinks he is getting.

[Andy Perrin]

Nothing is really equivalent to S8612. It's unique. Colin is correct, the Chinese charts are often not very accurate, and you can't just expect to get the same results by swapping a Chinese glass with a Schott. They are different animals.

[photoni]

5 hours ago, colinbm said:

Toni, et al, I think it would be better to use the makers designation for a filter, as the Schott & Chinese are very different filters & are not really equivalents.
Therefore the Schott & Chinese graphs will be different, Also the Chinese graphs are not accurate & the actual filter needs to be tested.
Then the actual graphs will be quite different.
What I an suggesting it that the graph above is not what Toni thinks he is getting.

 

Colin, Yes ... I understand, Schott charts are not fair, they are 1mm filters. Optima charts (blurry and fuzzy) are these ... but I doubt they are the same as Tangsinuo's.

.
All this is only approximate, it is not a perfect project. it is a quest to emulate collodion "in the best possible way".
Each chemical recipe has a different sensitivity that I cannot measure.

 

Then the fact remains that you professionals use special lenses
... BUT .... what do my old "normal" lenses see ... where should I cut the graphics ???

 

(for the wet plate I use Petzval lenses from 1880 and more modern lenses: industar 300 f4.5 - Zeiss tessar 360 f4.5 ... with a light anti-glare layer)
(for emulation I use Sony A7 with Nikkor-H 50 f2) (I have never tried the more modern Nikkor-D 50 f1,8)

 

I have to buy a Nemo and a ZWB-1 to test them with pinhole

 

>>> Andy :-((( BG39 will be enough for me

[Andy Perrin]

You would need to measure that petzval with a spectrometer like Ulf has been doing with other lenses. Nobody has measured that lens in UV that I know of, so it’s hard to know where the cutoff would be without a fresh measurement. Every lens is different in UV and seemingly minor things like adhesives affect the results dramatically, so there is no way to predict.