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UltravioletPhotography

Schott 2017 Filter Program - Graphs Compared


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Cadmium,

That legend is confusing to read. Can you clean it up?

I understand you're comparing 1.5mm vs 3.25mm, but the 0's add clutter.

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It is a little hard to show, no matter what colors I use, because most of the plots are very close together and/or overlapped, but here is a different color version.

It might be easier to see if I removed the U-360, S8612, and BG40 plots, but I wanted to leave them in there.

Both fall between 310nm and 320nm, have the same peak UV transmission, and both have the same Red/IR suppression.

My Kuribayashi 35mm only transmits down to 320nm, and has a good UV supporting curve for its UV range, so I don't think I would realize much if any difference between those two stacks.

post-87-0-84328400-1562214983.jpg

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Sorry for my confusion.

What I found confusing was the BG40 at 0mm and S8612 at d=0mm. Is there a way to include the multiple combinations but with out the 0mm reference?

 

I do agree with Ulf, you get more out of this than I. I have not been able to get multiple combinations on the same plot.

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See above...

I paste two of more combination plots into two (or more) Photoshop layers... that is how that part is done.

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I have never used Excel for anything other than the Schott program and for viewing a few spread sheets people have sent to me occasionally.

So if I can do this, anyone can.

 

Anyone can...- if they happen to use the same english Excel versions, operating systems and language settings as you do.

 

Unfortunately the UI of Excel is quite different between various versions. Currently I have only access to MacOS Excel 2011 and version 16 for Mac.

 

They are rather bug filled as MS seams to prioritise the number of functions and menus over that anything is working correctly.

Some bugs work like trap-doors. You can change a feature in a graph one way, but it is with my versions not possible to change it back.

 

I have been using both Mac and Windows-versions for more than 25 years and as MS constantly change how to work with the program it can be quite confusing and frustrating.

 

I would be grateful if you could share your modified spreadsheet with me.

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You have to get the program from Schott. If someone has a question about how to use the program, I will try to explain, if I know how.

 

The only two real differences between 2012 and 2017 that I can think of (other than cosmetics mostly) is 2012 shows 1E-10 Combi diabatic graphs (2017 only shows Combi diabatic graphs with 1E-05 unless edited),

and 2017 has the Combi T diabatic graph (2012 does not).

 

So far I have only found one little bug with the Schott filter program 2017 version, it is not a big deal, just a little annoying:

When you open the Combi T diabatic graph page, it will not load it, and makes an awful noise... and you will see the warning pop up like in the picture below.

 

Conditions:

Move from Data input page > T diabatic page = warning + sound

Move from Ti diabatic > T diabatic = warning + sound

Move from Ti linear > T diabatic = works fine

Move from Ti normalized > T diabatic = works fine

Move from T diabatic > any of the other three type graphs = works fine.

 

post-87-0-79256900-1562285595.jpg

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Well you do need Excel to work with the Scott program. I tried to open it in Libre office and didn't work. But I haven't tried the newest version.

 

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You can't use the Schott program alone, it has to be run in Excel. Both 2012 and 2017 versions run with my 2016 version of Excel.
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This is just a question semantics and not that important.

 

The Schott "program" is not a program but a document of the type workbook.

It is containing spreadsheets and graphs in several different tabs.

The cells in the spreadsheet can contain either data or equations.

The calculations are performed by the computer running an Excel application (or program) using the data and equations in the Schott Filter-calculation workbook.

 

As the Schott filter calculation-workbook is rather complex, it is likely to be difficult to run with other programs than the real Excel application.

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Yes I used the wrong term, probably causing confusion.

The Schott spreadsheet may need to be run only in Excel. And my first attempts opening it in the libreoffice Calc program, which has been able to run other spreadsheet and even older formats no longer supported by Microsoft Excel, failed.

Although I just noticed that version 6 is out and haven't tested in that version yet.

With the comments by Ulf, about trickiness in Excel, I wanted to see if an alternative could be used. I didn't test OpenOffice, but it can't save back in Microsoft file formats.

 

Just tested on my Android phone and it almost works in Google sheets. You can pull down filters and view the curves. Editing other than that is limited. Will need to test on a computer.

The free Android version of Microsoft Excel, by Microsoft opens and allows some editing on a phone. Little awkward, but oddly usable.

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I think I'm going to call the Schott program an "app".

 

I've thought about this for awhile and decided that OD-6 is probably far enough to go on charts.

But, I'd never quibble if presented with an OD-10 chart. :D

 

Cadmium has been amazing at figuring out how to tweak the Schott app. I'm really far far behind him. I also really enjoy playing with it to find ideal combos. I'd like to get some really good Hoya and other data sets to use in testing combos.

 

I never found that tutorial very useful.

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.For the record, I"m running the Schott app in Microsoft Excel for Mac 2011, v14.4.7.
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For those failing to modify to get OD-10 charts there is another workaround.

 

By creating a virtual custom filter with a transmission > 1 for all wavelengths and adding it to the stack you can lift the graph to inspect the low transmission areas normally hidden below OD-5

 

Here I have used that method to boost the measured transmission graph of my Baader U slightly above 400nm by 1000x:

post-150-0-46274400-1562433844.png

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I like seeing a little deeper than OD5. My feeling is that anything between OD4 and OD5 is as much as I want. But many want something that is OD5 or deeper,

and many standard stacks like the U-360 2mm + S8612 2mm are below OD5, and I want to see that on the graph, even if data below 1E-05 is calculated by Schott, I still find it useful and meaningful for below OD5 visualization.

There are many such things in mathematics, and science, that are rough calculations based on some kind of reasoning, that doesn't make them meaningless, and even more so that Schott included that deep data on their data sheets and in their program.

I might add that they don't include such deep data for all of their glass types, such as longpass filters which don't show any deeper data than 1E-05.

Why they include the deeper data on their data sheets for some of their glass types and not for others is unknown to me, and anyone's guess, except a few people at Schott who have phones...

When I first started using the 2017 version I missed the 'deeper that 5' when I was use to seeing deeper with the 2012 program.

Anyway, if the data is available, however it is calculated, it is valuable to me to see what they think it is, even if some deep parts of that are maybe not so real.

I have to believe the people at Schott who made their data sheets know something more than I do about the data they present.

 

Note that in all these data sheets the line that says: "The internal transmittance values, tabulated and graphically represented, are reference values only"

https://www.schott.c...jun-2017-en.pdf

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Ulf, that is very cool! I'm going to try that today.

 

A big thank you to Cadmium for all his investigations into the Schott filter transmittance app and to everyone who has contributed more insights.

 

 

Note that in all these data sheets the line that says: "The internal transmittance values, tabulated and graphically represented, are reference values only"

 

I would like to think that everyone understands that the transmittance charts, whether obtained via the Schott app or via direct spectral measurement, represent the transmittance possibility under "perfect" conditions. By the time the camera, lens and illumination are added transmittance will never match the charts. B) :rolleyes:

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Ulf, that is very cool! I'm going to try that today.

 

Use the same thickness as the reference thickness in the synthetic filter, when defining the gaining stack.

 

It might work to define a 10x gain filter with a reference thickness and then define the gain by stating a multiple of that ref-thickness.

Ref thickness 1 mm with 10 as gain. Used thickness 3mm => a 1000 gain. Not tested.

 

Be aware of that there are overload and clipping in the math. My Baader graph had 10e3 from 400nm.

It seams to work well in high OD areas.

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I thought your chart of the BaaderU was interesting. It shows the BaaderU as an OD-4. I had always estimated the BaaderU to be about an OD-4.5. It "feels like" an OD-4.5 in use. I've never found the IR to be a problem.

There are not many charts of the BaaderU available. Shane Elen has one. And I think Jonathan made one?

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I thought your chart of the BaaderU was interesting. It shows the BaaderU as an OD-4. I had always estimated the BaaderU to be about an OD-4.5. It "feels like" an OD-4.5 in use. I've never found the IR to be a problem.

There are not many charts of the BaaderU available. Shane Elen has one. And I think Jonathan made one?

Mine only goes to 800 or 850nm though (depending on which device it was) and I don't trust the data enough to be able to measure blocking down at OD3 and below. I wouldn't read too much into my blocking data. I'm not quite the whizz with these spectrometers as Ulf is.

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I'm rather confident that the measurement of the BaaderU is reasonably valid. I made an identical measuring session with the stack of S8612, 2mm and U-360, 2mm. the same day.

That stack showed no leakage at all around 700nm.

 

That is confirmed by pictures taken with my UV-gear. In some light situations I have seen some traces of leakage with the BaaderU in really UV-black areas, while when switching to the U-360-stack the leakage is gone.

According to the Schott transmission graphs for the U-360stack it should be well below OD5 at 700nm.

 

It could be that the OD of BaaderU filters can differ between production batches and there is AFAIK no real stated OD from Baader.

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It could be that the OD of BaaderU filters can differ between production batches and there is AFAIK no real stated OD from Baader.

 

Absolutely, we need to remember that the Baader venus filter is a dichroic filter with molecular sprayed layers. If you vigorously wipe it, you will damage these blocking layers.

During its generation, Heat, spray coverage and even location within a sheet, will effect the layers.

Whereas the Hoya U360 or Schott Ug1 is absorbing glass. You just polish it down to different thicknesses. Same as the S8612.

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Shane's Baader U graph:

http://www.beyondvis...BV3-filter.html

 

If I am reading Shane's Baader U graph correctly (the red line), then the Baader U has a maximum out of band OD of approximately 0.025% in the 885nm to 940nm + range (we can't see OD above 940nm in his graph).

That translates to between OD4 and OD3, closer to OD4

Here is the OD portion of Shane's graph that I reconstructed in the Schott filter program, and also the corresponding OD graph of the same range from the Schott program.

I think I got everything right... :) ...so let me know if I made a mistake.

(oops, I missed the little blip in the 700nm range)

 

post-87-0-49681000-1562646569.jpg

 

OD graph

post-87-0-36122100-1562646580.jpg

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Cadmium has been amazing at figuring out how to tweak the Schott app. I'm really far far behind him. I also really enjoy playing with it to find ideal combos. I'd like to get some really good Hoya and other data sets to use in testing combos.

 

Andrea, Thank you for your kind words.

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Shane's Baader U graph:

http://www.beyondvis...BV3-filter.html

 

I think I got everything right... :) ...so let me know if I made a mistake.

(oops, I missed the little blip in the 700nm range)

 

Your manual translation of Shanes graph from around 900nm looks reasonably correct, even if some details are missing.

 

The blip in the 700nm range corresponds well with my measurements of my filter. I also see a peak at around OD4 there.

 

The higher levels Shane record around 900nm can be either that his filter is slightly more leaky there or that my measurement in that range is not correct.

It could be either or both things.

 

The grating and detector has a lower sensitivity at 900nm than at 700nm, making my measurement here less accurate.

The peaks I have found at 900nm might partly be induced by noise.

The levels I see is still lower than what Shane see in his measurements, and normally noise would add not subtract to the detected levels.

 

Shane's measurements and filter date from 2008.

His filter must be at least eleven years old.

My Baader U is bought 2017.

There might have been an improvement in production of the coating quality, over the years, or I just got a better one by luck.

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