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Filter Transmission Charts

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#21 Andrea B.

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Posted 11 April 2015 - 21:42

I've added the Schott program link info to Post #1 and also some info about using the program for Hoya data in Post #23 (just preceding this one).
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#22 colinbm

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Posted 15 April 2015 - 01:14

Thanks Andrea for posting these.
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#23 Andrea B.

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Posted 02 September 2016 - 16:30

UVR Optics (UVR Defense Tech, Ltd)
AndreaU MK-II = UV-Pass
StraightEdgeU = UV-Pass

AndreaU MK-II 359FWHM48
Attached Image: AndreaU_MKII.jpg

StraightEdgeU 379FWHM52
Attached Image: StraightEdgeUgraph.jpg
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#24 Andrea B.

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Posted 04 September 2016 - 23:37

Uviroptics (Ebay)
LUV U2 = UV-Pass

LUV U2 359FWHM53
Attached Image: luvU.jpg
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#25 Andrea B.

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Posted 11 September 2016 - 16:43

From Ebay and Alibaba, here is some information about dual bandpass ZWB glass manufactured in China by Optima. I find several Chinese optical glass suppliers offering dual bandpass ZWB glass, but the Kopp equivalency charts list ZWB glass under the manufacturer Optima, so we will go with that.


Warning: Inexpensive "knock-off" filter glass from Ebay vendors labeled ZBW may not be of good quality. We have user reports of unacceptable levels of striation and pitting in some bargain glass. This is not to say that all ZBW filter glass is suspect, although we have reports that, in general, ZBW glass is not as efficient at transmitting UV. Remember, a small bubble or two *is* OK in either filters or lenses, but other glass flaws like pitting and striations are not.




ZBW3: The 2mm thick dual bandpass ZWB3 glass passes a significant amount of visible light - almost 30% transmission in the violet area. This ZBW3 filter glass could perhaps be for used as a UV+Violet+Blue+Green filter when emulating "bug vision" when stacked with an IR-blocker. ZBW3 (2mm) is not useable for UV-only photography even when stacked with an IR-blocker.

ZBW2: The 1mm thick dual bandpass ZWB2 glass transmits 8% visible as per the specs below. This is too high for a UV-only filter, so ZWB2 (1mm) is not useable for UV-only photography even when stacked with an IR-blocker. Look for a thicker version and check its transmission chart for visible leaks before buying.

ZBW1: Like the Hoya U-340 (1 mm), the Optima ZBW1 (1mm or 1.5mm) also leaks some visual green in the 550 nm range up to 1%. This will of course affect UV-only photography. We do not have any comparative examples yet showing how much and what kind of effect there is from the green leak. To effectively use ZBW1 for UV-only photography you would need a much thicker version than 1mm and you should stack it with some type of IR blocker.

Other thicknesses of ZWB filter glass may improve these transmission characteristics?

Note that the transmission peaks of this filter glass, as is the case with Schott or Hoya filter glass, will be shifted to the right when you stack it with some kind of IR-blocker made from blue-green glass.

Attached Image: zwb_trans2.jpg

Attached Image: ZBW_Trans.jpg
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#26 Andrea B.

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Posted 11 September 2016 - 17:34

Here is some filter glass equivalency information from Kopp Glass.

A complete chart can be found here: Filter Glass Equivalency Guide.

See also this chart from Newport Industrial Glass: Filter Glass Cross Reference


Attached Image: header.jpg
Attached Image: UV-pass.jpg


Attached Image: header.jpg
Attached Image: BG.jpg


Attached Image: header.jpg
Attached Image: IR-pass-comp.jpg


Attached Image: header.jpg
Attached Image: IR_red.jpg
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#27 JCDowdy

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Posted 12 September 2016 - 01:43

In addition to the KOPP filter equivalency there is also one from Newport Industrial Glass which we have discussed before in an older thread.

#28 Andrea B.

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Posted 13 September 2016 - 15:53

Thanks, John.
I added the reference to Newport's charts in the preceding post and in the index (first post).
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#29 Andrea B.

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Posted 14 October 2016 - 01:13

Schott UG11 = UV+IR, dual bandpass
Hoya U-340 = UV+IR, dual bandpass

UG11 (1.0mm)
UG11 (2.0mm)

U-340 (1.0mm)
U-340 (2.0mm)

Attached Image: ug11_u340.jpg
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#30 JMC

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Posted 17 August 2017 - 09:18

Baader U and Invisible Vision 308nm filter comparison

I recently got a 308nm band pass filter on loan from Invisible Vision in the UK (http://www.invisible...ts/accessories/). I did a direct comparison of this 308nm filter and the Baader U, using a Perkin Elmer Lambda 650S UV-Vis spectrometer (150mm integrating sphere) to measure transmission between 250nm and 800nm (1s collection time per nm). The graphs are shown below.
Attached Image: Baader U and Invisible Vision.jpg

Edit: Further work has demonstrated that using the 308nm filter alone results in significant IR contamination in the image, likely due to the much higher IR sensitivity of the sensor when compared to the low sensitivity of the sensor to the UV range which is primarily transmitted by the filter. I will share these results separately. Recommendation based on my results is that further IR filtration would be needed to ensure image could be classified as 'UV' when using a standard SLR sensor, however assessment should be undertaken by anyone to understand how it works for their application.

Edited by JMC, 17 August 2017 - 12:59.


#31 Andrea B.

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Posted 17 August 2017 - 16:59

Thank you, Jonathan! We appreciate these fiter transmission contributions very much.

Question:
  • Does the plotting routine permit any kind of graphing transformation of the region between 650-850 nm? Like, could it be expanded by 2x or 3x to show where the leak is occuring? Schott glass uses a particular logarithmic transformation they call "diabatic" to graph the dual bandbass filters and that expands the IR region in a certain way.
  • Alternately, will the plotting routine produce an optical density chart rather than this transmission chart?
  • Finally, is the gathered data available in chart or vector form so that it could be fed to Andy Perrin's MATLAB program to produce a chart rendering the 650-850 nm region in diabatic form?

I know you are very busy right now. There is no hurry on these questions. Just want to record them for future consideration as time permits you.
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#32 JCDowdy

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Posted 17 August 2017 - 20:35

Here is a transmission measurement of a NEEWER BK UV IR CUT filter you may wish to place in this thread.

#33 Andrea B.

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Posted 17 August 2017 - 21:40

Thank you John. Copied as follows.



NEEWER BK UV IR CUT
by John Dowdy, Ph.D.

I purchased one of these just over a year ago. Mine is labeled "NEEWER BK UV IR CUT" on the case and I cost $17.95 with free shipping. It is not a BG type filter, it is pretty much the real deal. That blue color is a reflection from the dichroic coating, held at a different angle the same surface looks pink. I have to confess I have not used it enough to say if it is any good or not.

The transmittance band is slightly blue shifted relative to the Baader UV/IR-Cut on both the short and long side. The Newer has 265nm HBW/383-648nm (probably not suitable for UVIVF) and the Baader 264nm HWB/418-682nm. You can see the waviness imparted by multi layered coatings. We also see a tip up toward the long side due to my neglecting to control internal reflectance from the filter back into the sphere because I like to see what it looks like. Since the throughput of the sphere is ~10% this is on the same scale as uncoated 1st surface reflection. I do not know what the reflectance of an unfiltered sensor would be.

Attached Image: neewerchart1.jpg

If we look at the spectra on a log transmittance scale we a can see just how deep the blocking really goes. I did not scan them beyond 800nm, that is as far as the double grating OL-756-PMT spectroradiometer will scan. One of these days I will scan them out to ~1100-1200nm with a double grating InGaAs spectroradiometer to see just how well the NIR side is blocking.

Attached Image: neewerchart2.jpg
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#34 Andrea B.

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Posted 17 August 2017 - 21:44

Optima ZBW1 1mm UV+IR Dual Bandpass with ~1% visible leak in 400-660 nm.

Optima ZBW2 2mm UV+IR Dual Bandpass with violet leak and ~1% visible leak in 400-680 nm.

Optima ZBW3 2mm UV+IR Dual Bandpass with large 28 to 9% violet leak, 1 to .1 % blue/green leak, yellow/orange suppression, 8-54% red leak 670-700 nm.


Attached Image: zbw1.jpg

Attached Image: zbw2.jpg

Attached Image: zbw3.jpg
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#35 Andrea B.

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Posted 17 August 2017 - 22:24

ZBW1 2mm
ZBW3 1.5mm
OBG39 2.5mm

From JMC, Ph.D.

I recently bought a few filters from Igoriginals on eBay and wanted to share the transmission data I measured for them. The filters were ZWB1 (2mm), ZWB3 (1.5mm) and BG39 (2.5mm). All in 52mm filter thread and priced at 25USD each. I ran them on a Perkin Elmer Lambda 650S UV-Vis spectrometer (150mm integrating sphere) to measure transmission between 250nm and 800nm (1s collection time per nm). The graphs are shown below.

Attached Image: zbw1zbw3objg39.jpg
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#36 JMC

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Posted 19 August 2017 - 19:27

View PostAndrea B., on 17 August 2017 - 16:59, said:

Thank you, Jonathan! We appreciate these fiter transmission contributions very much.

Question:
  • Does the plotting routine permit any kind of graphing transformation of the region between 650-850 nm? Like, could it be expanded by 2x or 3x to show where the leak is occuring? Schott glass uses a particular logarithmic transformation they call "diabatic" to graph the dual bandbass filters and that expands the IR region in a certain way.
  • Alternately, will the plotting routine produce an optical density chart rather than this transmission chart?
  • Finally, is the gathered data available in chart or vector form so that it could be fed to Andy Perrin's MATLAB program to produce a chart rendering the 650-850 nm region in diabatic form?
I know you are very busy right now. There is no hurry on these questions. Just want to record them for future consideration as time permits you.
Hi Andrea, The software for the UV Vis is relatively basic as it's aimed at an analytical chemistry lab. As such there are no fancy plotting options, just % tranmission. The data is available as simple xy data for Excel though, and that's how I do all my charts (I'm 'a bear of little brain' when it comes to this sort of thing). As mentioned in another post I have concerns over plotting the data logarithmically, as I only trust it to about 0.1% - areas which should be 0% transmission, or effectively 0% are being measured as -0.1%. As such I believe plotting it logarithmically, could introduce artifacts which aren't real.

Edited by JMC, 20 August 2017 - 07:41.


#37 JMC

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Posted 19 August 2017 - 19:38

Edit: added Baader UV/IR Cut L filter (Item number 2459210A) 25th August 2017

Two different B+W 486 UV/IR cut filters, and Baader UV/IR Cut L
I bought a couple of B+W UV/IR filters recently. Both marked up as B+W UV/IR cut F-PRO MRC 486. The 77mm one was in new style packaging, and was new stock. The 58mm one was in older stye packaging and was second hand.

Also bought a Baader UV/IR cut L (Item number 2459210A) second hand from a well known online auction site. I did run this both ways round in case the coatings on each side were different but the spectra were the same, so I only plotted one here.

I ran them on a Perkin Elmer Lambda 650S UV-Vis spectrometer (150mm integrating sphere) to measure transmission between 250nm and 800nm (1s collection time per nm). The graphs are shown below.
Attached Image: Baader UVIR and BW.jpg

Similar overall behaviour for the 2 B+W filters, but with some subtle differences in the fine structure - I'm guessing due to changes in coating technique/batch. 50% max occurs at 683nm and 391nm +/-1nm for both filters. The B+W's had measurable transmission into the IR and UV. The Baader UV/IR cut L was significantly different to the B+W ones. 50% max now 678nm and 419nm with a much cleaner cutoff at both ends.

Edited by JMC, 25 August 2017 - 18:02.


#38 Andrea B.

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Posted 19 August 2017 - 21:01

As Visible bandpass filters, these 486s certainly do provide a lot of UV and IR !!!!!
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#39 Andy Perrin

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Posted 19 August 2017 - 23:04

Quote

I only trust it to about 0.1% - areas which should be 0% transmission, or effectively 0% are being measured as -0.1%. As such I believe plotting it logarithmically, could introduce artifacts which aren't real.

...literally not real (numbers)!

#40 JMC

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Posted 31 August 2018 - 13:24

In a recent thread there has been discussion about the "Nikon FF Filter";

http://www.ultraviol...so-much-cooler/

I recently got one of these filters, and here is a measured spectra (run on my Ocean Optics spectrometer).

Attached Image: Nikon FF filter.jpg

It matches very well with the spectra provided in the UV Nikkor 105mm manual;

http://www.company7...._39pg.108.p.pdf

There is definitely quite a lot of visible light coming through as I can see through it quite easily.