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UltravioletPhotography

Filter Series :: 15 Yellow and Orange Longpass Filters :: Transmission Charts


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I have measured the transmission of fifteen of my yellow and orange filters.

 

The filters looks like this side by side:

post-150-0-93946500-1579679642.jpg

It is obvious that I do not need many more yellow and orange filters. :smile: :smile: :smile:

 

It all started with Nisei's topic about his two B+W 099-filters. https://www.ultravio...r-bw-099-filter

He kindly sold one of them to me and I wanted to do a comparison to other alternatives.

 

I will post the detailed comparison of the 099 in another topic, later.

 

First some measurement background and how to interpret the graphs.

As we are interested in wavelengths around 550nm I chose to calibrate the spectrometer against the 546.074nm peak from my calibration lamp.

This means that the wavelength-scale in this area is very accurate, while other areas might differ a bit, but normally less than 1nm.

To avoid as much crosstalk as possible I only used the halogen light-source operating from ca 450nm and upwards into IR.

No data is valid below 450nm. That can be seen in the lower part of this diagram:

post-150-0-11863100-1579538060.png

 

After stabilisation time and dark-spectrum calibration the spectrometer is stable.

The red graph close to 0% was taken last, proving that the baseline has not shifted significantly.

We can still see the graphs are offseted in the attenuation areas by 2-3%.

The filters attenuation is definitely better than that, but this measurement session was only intended to find the cut-on wavelengths, not the attenuation.

post-150-0-00354900-1579538433.png

 

Before and after each filter measurement the 100% calibration was verified and if needed redone. (as the blue curve at 100%)

To save time I only used 100 average passes. This sometimes gave a slight waviness of the graphs due to noise. In reality these filters have completely smooth transmission curves.

The SMOOTHING ON is just a boxcar averaging of thee bins (ca 2nm), to limit the curves's noisiness slightly

post-150-0-58823300-1579538689.png

 

This is an overview of all fifteen filters:

post-150-0-26343800-1579539150.png

The brands, filters and associated curve-colours:

  • B+W 099 -- Orange
  • B+W -- Red
  • Tiffen -- Green
  • Nikon -- Dark Blue
  • Kenko Y48 @ 470nm -- Pale Blue
  • Hoya O (G) @538nm -- Pale Blue
  • Minolta Y52 -- Dark Green
  • Marumi MC-Y2 @480nm -- Dark Green

When I went through the graphs again I realised that the challenge was extra difficult by assigning the same colour to some of the filters.

The tell-tale nobody found was the less steep slope and inferior pass transmission typical for the Tiffen-filters.

 

 

 

 

It would be interesting to see if anyone can guess what brand each colour indicates even without knowing the brand names. :smile:

There are some very distinctive tell-tales if you know filters well.

 

After some days I will add a list of the names of the filters to this post.

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Its hard for me to tell. But I see five different colors. So I assume 5 brands.

My guess is that the Nisel filter is orange, with 50% at 522nm.

Green is a russian filter.

Red is B+W

Light blue is tiffen

Dark green is Hoya

Purple is Cadmium Scott filter

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Was Nisei's more yellow than your 099 in real life? Did it scan differently than it should have?

Yes it was more yellow than my 040 in real life!

 

It scanned nicely, just as all the other filters and was surprisingly good. :smile:

I think that modern specifications do not act retrospectively backwards in time.

The 099 design specification must have changed sometime long ago when they decided to use OG550 for 099 instead.

It might been seen as an improvement. We just do not know when and why.

 

The Nisei 099 is definitely an IR optimised filter, with a, for IR, good single-coating.

It gave the orange curve in the graphs above.

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The orange curve is about 522nm at 50%, so lower than 550nm. Closer to OG530 2mm, but not exactly that either, not OG515nm 2mm either, something between those two.

Of course, i don't know the thickness of any of your filters, which matters a lot.

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Its hard for me to tell. But I see five different colors. So I assume 5 brands.

My guess is that the Nisel filter is orange, with 50% at 522nm.

Green is a russian filter.

Red is B+W

Light blue is tiffen

Dark green is Hoya

Purple is Cadmium Scott filter

 

David, I am impressed by your guesses!

 

You named and matched two brands correctly to their curve colours.

Two of your suggested 'brands' are not among the tested.

 

I wont say more for now, as I hope for others to join the challenge.

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Do your filters bottom out at 2.5% transmission? They are all above 0, but 2.5% seems high.

 

Some of the IR-light, passed by the filters, is bouncing around inside the spectrometer, causing a false offset.

That is quite normal for an array-spectrometer. You have to understand how it works to interpret the graphs correctly.

I thought I explained that in the text, but maybe not well enough.

 

Just ignore the 2-3% baseline-level. It is false and not caused by the filters.

To find the OD in these regions a different way of measurement without a lot of IR in the light-source must be used.

I can do that sometime later for one or two selected filters.

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Thanks for all the measurements Ulf!

B+W got back to me about the matter but judging by their reply I don't think they took much time looking into it:

 

Thank you for your mail.

 

Checking with our B+W-Filter team it seems that the substances in the glass substrate have changed and are fading over the years. This could be possible with 50 years old filters.

 

Mit freundlichen Grüßen

Best regards

 

Well then the 2 filters must have faded miraculously the same... :tongue:

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Not sure at all but here goes:

 

Red 40% @ 550nm = B+W 040

Light blue 60% @ 540 = Tiffen #16

Red 50% @ 490 = B+W 022

Dark blue 60% @ 520 = Kodak Wratten #12

Red 40% @ 560 = B+W 090

Dark green 30% @ 520 = Schott OG530

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@ Nisei

The B+W-Filter team must be the sales person responsible for the filters.

Sales departments always are super well informed about deep technical details like adding margins and prices.

That was a real nonsense answer.

 

Your more detailed list for my filter-challenge have more correct lines than David's suggestion above.

Thank you for your input.

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I don't think anyone there know.

 

The original B+W company was bought by Schnieder 35 years ago 1985.

Your 099 is likely quite a bit older.

The keep/container is of a rather old model.

My unqualified guess is early around 1960

They feel like from the same period as some of my early Novoflex-stuff

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Its hard for me to tell. But I see five different colors. So I assume 5 brands.

My guess is that the Nisel filter is orange, with 50% at 522nm.

Green is a russian filter.

Red is B+W

Light blue is tiffen

Dark green is Hoya

Purple is Cadmium Scott filter

 

Purple is Cadmium Scott filter

Not sure, but I don't think he has those in that range.

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I don't think anyone there know.

Ah well, perhaps it's not that important anyway :smile:

We know now they've changed it at some point in history for whatever reason without changing the name/number.

Makes you wonder if they did this with other filters as well (anyone with a pink 090 inhere? :rolleyes: )

Funny though, how I bought 2 of those from the same era without knowing how a "modern" 099 looked and always wondered why people were calling it orange :lol:

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Get an orange one, and compare results, decide which you like best.

At some point it all comes back to 'actual photos', after all, isn't that the whole point?

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I didn't mean it so much as a response to your last post above, I meant it in general going back to your other original topic about finding another 099 filter,

because you liked how your 099 filter(s) worked for your photos.

So why not just get one of the (newer?) more orange 550nm or 040 filters and see how they work for your photos compared to your more yellow (to the eye) 099 filter version.

 

You had asked:

"I already have a 52mm 099 filter which I'm using for IR photography (IRG) but also need a 67mm.

Since they are pretty hard to find nowadays I'm looking for an alternative.

Comparing different graphs I've found that the (also discontinued but easier to find) Hoya Orange (G) filter comes closest to the 099.

The Hoya Ya3 Pro starts a bit too high in my opinion, making it around 570nm, not 550nm.

Has anyone compared both in real world tests?"

 

https://www.ultravio...dpost__p__31629

 

What really matters is how the photos compare. At the worst you will end up with a slightly new option/look, I don't know.

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It seams like my challenge was too strange to attract many answers.

I will add the missing information now, by editing the first post, to keep everything together.

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So,

Your B+W 099 (orange line, dark yellow filter) that you got from Nisea scans at 522nm @50% (definitely not a 550nm filter).

Your B+W 040 (red line, orange filter) scans at 552nm @50%, right about where it should be (made of Schott RG550 filter glass + coated).

Your B+W 041 (red line, darker orange filter) scans at 563nm (made of Schott RG570 glass, a little lower than where it should be, namely 570nm,

partly because of thickness I estimate, 3mm is the technical thickness for Schott longpass glass), but close.

Your B+W 022 (red line, yellow filter) scans at 491nm, about where it should be, again depending on thickness (made out of Schott GG495 filter glass + coating).

Everything makes sense, except still that 099 you got from Nisea, still no reasoning there.

 

I still suggest that someone do an actual photo comparison between the Nisea 099 yellow filter and one of the more orange looking Schott RG550/usual B+W 099 like I have two of, or the B+W 040 like I also have,

to see how they compare in an actual photograph.

I would rather doubt myself that they are exactly the same, however, it can be a bit hard to differentiate 522nm from 550nm in photos, and the point being, it may not be enough to worry about depending on what you are wanting.

I just think a photo comparison would be interesting since that is what the original use was about.

I would do it, but I don't have one of those yellower 099 filters.

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Everything makes sense, except still that 099 you got from Nisea, still no reasoning there.

 

I still suggest that someone do an actual photo comparison between the Nisea 099 yellow filter and one of the more orange looking Schott RG550/usual B+W 099 like I have two of, or the B+W 040 like I also have,

to see how they compare in an actual photograph.

I would rather doubt myself that they are exactly the same, however, it can be a bit hard to differentiate 522nm from 550nm in photos, and the point being, it may not be enough to worry about depending on what you are wanting.

I just think a photo comparison would be interesting since that is what the original use was about.

I would do it, but I don't have one of those yellower 099 filters.

 

If we assume that the B+W 099 originally was intended to be used together with Kodak AIR-films and similar, the colour of the old version Nisei and I have makes very much sense, as it has the same tone as the Tiffen Yellow12. That was the filter Kodak recommended, for those films.

 

The B+W 099-filter have an improved performance, compared to Tiffen 12, both in suppressing blue light and transmitting other colours.

The reason for later changing to OG550 (from OG530?) for modern 099-filters is unknown.

It might have given better results in some aspect for the photos taken with those films.

 

OG530 was used in the now obsolete B+W 023.


I guess you mean Nisei or me when you say someone.

I don't think Nisei have a 040-filter and we are the only ones, we know about, that have those old yellow 099-filters.

 

To use the old B+W 099 for comparison to pictures taken with a OG550-based filter, is best done with motifs having much colours in the transition-area around 530nm, (green).

There is not much green foliage here yet.

Let me come back on that comparison issue later.

I might need a reminder.

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It looks like the 099 you have from Nisei is about 520nm to 530nm range (from your graph), and it is the same color as the Schott OG530 2mm seen in the pic below.

Not surprising it is a different color than what one would expect from a 550nm longpass filter. My B+W 099 is more orange and matches the Schott OG550 filter below.

So the 099 you have is actually more like an OG530 or a B+W 023.

 

The entire Schott 500nm to 600nm range of longpass filters. OG515 through OG590 @2mm thick (it is best to measure and know the thickness of any filter).

post-87-0-96658200-1579710389.jpg

 

Schott OG longpass filter range @2mm thick

post-87-0-01268400-1579711095.jpg

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I didn't mean it so much as a response to your last post above, I meant it in general going back to your other original topic about finding another 099 filter,

because you liked how your 099 filter(s) worked for your photos.

So why not just get one of the (newer?) more orange 550nm or 040 filters and see how they work for your photos compared to your more yellow (to the eye) 099 filter version

What really matters is how the photos compare. At the worst you will end up with a slightly new option/look, I don't know.

Ah yes I appreciate the advice Steve. It just sounded a bit like we don't need to talk about the technical side of things while, as I see it, this forum is meant for just that :smile:

What I'm curious about is why there was a shift in filters from yellow to orange used for IR color photography.

Logic tells me we only want to block blue and use that channel for IR while passing red and green for visible light.

So yellow 520-530nm would suffice (my 099 is really close to that).

But nowadays (and even before the digital era) the preference has shifted to 550nm filters, also blocking part of the green part of the spectrum.

Of course I can just get me an orange 550nm and see if perhaps I get better results than the 099 I've been using up till now but before I do I'd like to know the reason why people started using it instead of 520-530nm.

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I still suggest that someone do an actual photo comparison between the Nisei 099 yellow filter and one of the more orange looking Schott RG550/usual B+W 099 like I have two of, or the B+W 040 like I also have,

to see how they compare in an actual photograph.

In my (tablet) browser, we're already on page 2 of this topic and in the meantime Ulf has posted a picture with all the filters in his first post.

Just thought I'd mention this since people may have overlooked it.

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The Hoya filters confuse me.

 

I have a Hoya O(G), R25A, and Y(K2) in the cupboard from the days of film. These are potentially of use now, esp. for IR. But the naming of filters in the current Hoya datasheets use a different convention, which includes the wavelength where transmission reaches 50%.

 

It looks to me as though these are the equivalences between old and new names:

 

R25A = R60

O(G) = O54

Y(K2) = Y48

 

Can anybody confirm this?

 

I also have a Kodak 80A (A to D converter) - does anyone have transmission data for this outside of the visible range?

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