Russian Lomo UV filters transmission (3mm and 5mm)

[JMC]

A couple of filters arrived today from Russia. They are 3mm and 5mm thick microscope filters (32mm diameter). I got them from ebay and they were 13USD for the 2 filters and 9USD for the shipping, so for that it was worth a gamble. The filters;

 

Here's the transmission spectra for them, full scale, and focusing on the 0-1% transmission range to see whether there is any visible light getting through.

 

 

Looks like they could be useful filters.

 

If anyone knows any more about these, please feel free to comment as I don't know anything about them (the ebay advert called them UFS 6-3 and UFS 6-5).

[dabateman]

Jonathan,

Those are YoC 6 filters. This snap shot of a Russian catalog someone here sent me might help.

[Cadmium]

Be aware, Russian filter graphs are frustrating to read or compare to other standard filter graphs, because the 20nm segments become more and more compressed and closer together as the graph moves to higher nm.

Even for example, the 300nm to 400nm range in the graphs above, the 300nm to 320nm is wider than the 320nm to 340nm, and then look at the 380nm to 400nm, and so on, as all these segments become narrower and narrower,

until eventually your mind becomes compressed into a singularity and you disappear.

Exaggerating? Perhaps, but I would much rather refer to Jonathan's scan than any Russian graph I have ever seen, they are weird and frankly misleading.

I have spent time with some, uncompressing each segment to try to normalize their range, but it is rather time consuming, and frunstrating.

You can not do overlays with these Russian graphs unless you first resize each segment.

 

http://www.elektrosteklo.ru/Elektrosteklo_Color_Glass_Spectral_Transmittance.pdf

[JMC]

Thanks for the screenshot David. I think that's part of the issue I've had when trying to get filters like this - the naming. So far I've seen them described as YOC, UFS and UVG. Makes searching for them a bit complicated.

[ulf]

Thanks for the screenshot David. I think that's part of the issue I've had when trying to get filters like this - the naming. So far I've seen them described as YOC, UFS and UVG. Makes searching for them a bit complicated.

Then I think this link also can be useful:http://www.elektrosteklo.ru/Stock.htm

 

Colored glass

( colored glass filters) within ( ) are the non-cyrillic designations

[JMC]

Cheers Ulf.

[Andy Perrin]

Be aware, Russian filter graphs are frustrating to read or compare to other standard filter graphs, because the 20nm segments become more and more compressed and closer together as the graph moves to higher nm.

Even for example, the 300nm to 400nm range in the graphs above, the 300nm to 320nm is wider than the 320nm to 340nm, and then look at the 380nm to 400nm, and so on, as all these segments become narrower and narrower,

until eventually your mind becomes compressed into a singularity and you disappear.

Exaggerating? Perhaps, but I would much rather refer to Jonathan's scan than any Russian graph I have ever seen, they are weird and frankly misleading.

I have spent time with some, uncompressing each segment to try to normalize their range, but it is rather time consuming, and frunstrating.

You can not do overlays with these Russian graphs unless you first resize each segment.

 

http://www.elektrost...ansmittance.pdf

 

Hehehe. The problem is you are approaching it the wrong way. The right way to do it is to use a program that can extract data from logarithmic charts and replot it. I have an application called GraphClick which is unfortunately no longer available that does it, but there are plenty of free online alternatives. You can just set up the axes and click on the graph to select points. Then you replot the data in Excel or whatever your favorite graphing program is.

 

The red dots are where I clicked, and I have previously input the x and y axis limits into the software so it knows where I'm clicking.

 

Here are both of the Russian charts (UV-vis and infrared) for YøC6 on the same axis with no distortion in Excel. The raw data is also included below.

 

Here are the text files with the raw numbers in case you want to put them in the Schott program, Cadmium or anyone. Bear in mind they are digitized by clicking on the graph so the accuracy is not perfect (in fact you can see that above from the area of overlap from the two data sets).

Y0C6.txt

Y0C6 infrared.txt

[Cadmium]

Andy, Looks good.

[Stefano]

How does the program know/you know the wavelengths? Does it recognise the black vertical lines?

[dabateman]

This like data thief, you steal the curve and set the points.

My PhD supervisor had data thief. I still remember every time it loaded it would say:

"So you want to steal some data, eh"

Great times.

[Andy Perrin]

Stefano, you move the dashed green lines to be on top of two vertical tick marks and two horizontal ones and there is a dialog to set the values at those locations and whether the graph is linear or logarithmic in each direction. Then it just interpolates.

[Cadmium]

Here is an example of one I adjusted to make it compatible for overlay. Not the same glass type, just an example. Of course I like your method better, but I don't have any such software.

This was to compare Schott BG3 with Russian CC4. Frankly, I would rather have a spectrometer like Jonathan and Ulf have. That would be much more handy for so many things.

[Andy Perrin]

The main thing I’ve learned from this board about spectroscopy is that it’s challenging to get right!

[JMC]

The main thing I’ve learned from this board about spectroscopy is that it’s challenging to get right!

Bingo. Like any measurement system, the information provided is only as good as the person providing it. As I've seen it's very easy to get misleading results.

[ulf]

Bingo. Like any measurement system, the information provided is only as good as the person providing it. As I've seen it's very easy to get misleading results.

That is true especially when creating untested measurement setups with optical building blocks like array spectrometers, optical fibers, collimators light sources and integrating spheres like we do.

You have to profoundly understand the limitations and pitfalls of the components and setups.

Sometimes you can do some verification tests to confirm the validity of the results, but you must always be somewhat mistrusting about the results and check what you have done.

 

When something unexpected shows up suspect some foul play of the setup and try to pin it down buy thinking one level deeper.

That is how we cracked the odd results Jonathan saw with his Hoya R72 filter:

https://www.ultravio...tra-and-images/

And fast forward to the explanation 105 posts later:

https://www.ultravio...dpost__p__30621

[Cadmium]

Part of the confusion with the 'bandpass' graph plot of the Hoya R72 was that Kenko had posted a graph on their Hoya R72 page, which was like Jonathan's scan,

I think Kenko used a similar setup to scan the filter also. They have since removed the 'bandpass' graph version, thanks to us probably.

If you go to some of those links in that topic you will not see the older removed 'bandpass' version any longer, which can make reading that topic now even more confusing.

 

I believe this may have been the graph Kenko (hoyafilters)had posted at one time, can't be sure, but I can't think of anywhere else I could have got it from, I only linked to it on here back then.

(keep in mind, hoyafilters is not Hoya, it is Kenko)

[JMC]

Steve, yes that was the original graph which initiated my confusion about all that. Interesting to know that they have now removed it. I did a quick search for 'hoya r72 transmission' on Google and there are a couple of people who still show that image or a figure based on that image.

[dabateman]

 

Bingo. Like any measurement system, the information provided is only as good as the person providing it. As I've seen it's very easy to get misleading results.

 

Jonathan, that sounds a little harsh. I would say you NEED to know the limits and configuration of your tools and instruments.

You can tap a nail in with a metal wrench. But the nail may not be straight in or might bend at a point. Doesn't mean all of that nail lot will bend at various points or will not cork straight in. The tool used affected the results and you need to always take care to see when and if that is occurring.

 

People also need to take care in reviewing results. It maynot mean what you are extrapolating it to mean. But simultaneously, I know people have an expectation to what a plot will tell them. I should go back and add warnings to my transmission plots as they aren't configured to tell you all the information that a person usually expected from that type of plot.

My spectra just indicate limit of light through and can give 50% indication of where that cut off is starting to occur in the UV range. I haven't optimized the IR range yet. Not the true transmission intensity at each wavelength like people are used too. So I should make that warning.

[JMC]

Jonathan, that sounds a little harsh. I would say you NEED to know the limits and configuration of your tools and instruments.

You can tap a nail in with a metal wrench. But the nail may not be straight in or might bend at a point. Doesn't mean all of that nail lot will bend at various points or will not cork straight in. The tool used affected the results and you need to always take care to see when and if that is occurring.

David, I don't think it sounds harsh and that wasn't my intention. I was merely making an observation based on my experience. All systems have limits, and as you say any operator should know those - I drew conclusions on the R72 without knowing them. In my area (skin) I've seen too many instances of people who have bought expensive pieces of kit, only to think that buying it made them instant experts. Albert Kligman who was one of the pioneering skin measurement experts had a saying which has stuck with me over the years - "A fool with a tool is still a fool".

[ulf]

Albert Kligman who was one of the pioneering skin measurement experts had a saying which has stuck with me over the years - "A fool with a tool is still a fool".

 

That is a really good saying I must remember.

It is good as long as you do not have to tell the fool.

Then sometimes even a fool might be improved upon, carefully helped and educated.

[Andy Perrin]

Yeah, I am very much of the “fool with a tool is still a fool” opinion. I don’t think you were harsh, Jonathan.

[Dmitry]

I got this color glass kit for reasonable low price. Some are missing, but 95 are in very good condition.

 

Is there a table of correspondence of Russian names to the Schott catalog?

[diant]

A couple of filters arrived today from Russia. They are 3mm and 5mm thick microscope filters (32mm diameter).

...

If anyone knows any more about these, please feel free to comment as I don't know anything about them (the ebay advert called them UFS 6-3 and UFS 6-5).

 

These are both UVG-6 glasses (УФС-6 in Russian), in first approaching - an analog of such silicate UV glasses as UG-1 or U-360.

Of course there are some small difference because exact recipes are different (more Zn and K in UG1 for example vs more Na and the base Si in UFG-6 etc.)

But in first approaching they are all the same Ni-Co-doped silicate glasses and all have a huge OD in most visible range.

UVG-6 (3mm) for example has OD > 10D in 420-677 nm interval.

Because it often be formed in 5mm thickness plates, such interval became wider: 410-685 nm.

 

Now, my question:

I am a little surprised about china ZWB glasses - namely, I've read and more than one times that ZWB glasses have poor visual blocking. Why? Which is the reason for it?

If they are glasses (but they are really usual glasses tinted by metal oxides), and these metal oxides are essentially the same in China as in all other countries - how can we melt the like mix materials with the same Ni and Co additives and obtain a good OD in visual region for the Schott's or Hoya's UV-pass glasses and poor OD in visual region in China glasses?

Can anyone propose some explanations for it?

[Andy Perrin]

I don't know where you read that, but the general issues with Chinese glasses have been that there is higher variability between different batches and different manufacturers relative to Schott/Hoya. Many here have had experiences where one Chinese filter is fantastic and another is so-so. You seem to be saying there is systematically less blocking in visible for ZWB glasses, but I don't remember seeing that? Just variability.

[diant]

I read this here for example. But it will be very good to take 1mm sample of any ZWB glass and measure its spectrum in spectrophotometer.

If even spectrophotometer have only 4,0 OD then we could easy estimate its OD upto 8 OD for 2mm samples and upto 12 OD for 3mm samples.

By the way, many years ago I took the spectrum of my UVG-6 (УФС-6) glass sample 80x80x5mm. Here it is:

 

PS. My device had OD4 only (and sample was too thick - 5mm), so I had only such data (in percent):

713,00, 0,0488

712,50, 0,0366

712,00, 0,0244

711,50, 0,0244

711,00, 0,0122

710,50, 0,0122

710,00, 0,0000

709,50, 0,0000

709,00, 0,0000

708,50, 0,0000

708,00, 0,0000

...

400,00, 0,0000

399,50, 0,0000

399,00, 0,0000

398,50, 0,0000

398,00, 0,0122

397,50, 0,0244

397,00, 0,0366

396,50, 0,0610

396,00, 0,0854

395,50, 0,1221

395,00, 0,1831

394,50, 0,2441

394,00, 0,3296

...

360,00, 54,26

359,50, 54,38

359,00, 54,52

358,50, 54,61

358,00, 54,66

357,50, 54,71

357,00, 54,75

356,50, 54,75

356,00, 54,71

355,50, 54,66

355,00, 54,61

354,50, 54,55

354,00, 54,48

353,50, 54,36

353,00, 54,21