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Old 13th January 2009, 02:07 PM
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Default Wratten 44A Filter

I read that the above is useful for landscape work with black and white. I gather it is a Blue/ Green filter. What would be the nearest to a 44A and should I be able to acquire one in a 39mm screw thread? I also read that it gives black and white film orthochromatic qualities
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Old 13th January 2009, 02:46 PM
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Blue Green is cyan which is minus red.
The B+W filters for this are CC Filters Cyan (blue-green) 05, 10, 20, 40 on Page 23 of their filter manual PDF which you can download by clicking on the below link. (using right click and "save target as" might be best). It's 7MB.
40 takes out most red. 05 the least.
They are available in a 39 thread. See towards of end document for sizes.

http://www.schneiderkreuznach.com/pd...r_handbook.pdf
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Old 13th January 2009, 03:41 PM
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Quote:
Originally Posted by kennethcooke View Post
I read that the above is useful for landscape work with black and white. I gather it is a Blue/ Green filter. What would be the nearest to a 44A and should I be able to acquire one in a 39mm screw thread? I also read that it gives black and white film orthochromatic qualities
You must first consider what effect you want the filter to have. In monochrome work filters lighten their own colour and darken opposite. In landscape work we usually use green to lighten foliage, however rarely would we also want to lighten a blue sky. So it is more usual to use a yellow/green filter which lightens foliage and at the same time darkens the sky.
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Old 13th January 2009, 04:45 PM
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This company supply B+W, Hoya and Cokin filters at a reasonable price. Just go to 'shop by brand'.
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Old 13th January 2009, 11:52 PM
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I purchased a Wratten #44 equivalent from B+W, their 470, in Germany in 1982. It is the only B+W filter to have failed me, becoming heavily "frosted" over within just 3-4 years, as if sprayed with several heavy coats of clear matte spray, entirely unusable. Since this happened after my return to the US, the US distributor wouldn't cover it under their lifetime warranty because it was a German purchase. When I tried to order a replacement a few years ago from a large New York photo store, B&H, the US distributor said it was no longer available, at least in the 55mm size I ordered.

The effect of the 470 or Wratten #44 is to give an orthochromatic response to panchromatic films by blocking red. It lightens blues, foliage, the sky, and shadows. Ansel Adams discusses it in his books.

I have also been told recently that the greater density B+W neutral density filters have been taken out of production, but was not told specifically which densities and sized. I was looking for a 55mm ND 113 if I recall correctly, and couldn't even order one.

For the record, I own many B+W filters and prefer them over others I've used except perhaps Heliopan, which is similar in quality, both optically and mechanically.

A rather heavy cyan filter might work as a substitute for a Wratten 44(A), perhaps a CC filter like a 30, 40 or 50 CC unit cyan. The 470 had a > 50% transmission between 425 and 570 nm.

Lee

Last edited by lee l; 14th January 2009 at 12:03 AM.
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Old 14th January 2009, 12:29 AM
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I tracked down a spectral chart for the 44A (it's upside down compared to most charts)

As Lee suggests, you would need a very strong CC Cyan filter as it looks like the 44A had complete cutoff of part of the red section of the spectrum.

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Old 14th January 2009, 10:47 AM
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I have a B+W 081 medium blue filter, exposure factor 2x, which I've used to enhance mist and fog. Don't expect a quantum leap but it does give some enhancement.
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Old 14th January 2009, 03:59 PM
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The B+W 081 is a good close equivalent of the 470. It's shifted blue a bit relative to the 470, >50% transmission between 360 and 540 nm, so it passes a bit less yellow-green and more UV. Looks like a good choice if you find it more readily than the B+W 470.

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Old 14th January 2009, 05:54 PM
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Well I think the CYAN filters have a more closely matched curves to the 44A but if the film you are using doesn't have any sensitivity over 700nm then an 81 is pretty close.
Don't know what the sensitivity curves for orthochromatic films were but current ilford sheet film seems to have cutoff at around 550nm and kodak the same. So an 81 may work for you. And be a lot cheaper I expect. But it depends exactly what you are looking for. An 81 is a cooling filter for colour work which figures as it is a minus red filter.
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Last edited by Argentum; 14th January 2009 at 06:49 PM. Reason: Oops ! I meant Cyan and not magenta.
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Old 14th January 2009, 10:19 PM
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Quote:
Originally Posted by percepts View Post
Well I think the CYAN filters have a more closely matched curves to the 44A but if the film you are using doesn't have any sensitivity over 700nm then an 81 is pretty close.
Don't know what the sensitivity curves for orthochromatic films were but current ilford sheet film seems to have cutoff at around 550nm and kodak the same. So an 81 may work for you. And be a lot cheaper I expect. But it depends exactly what you are looking for. An 81 is a cooling filter for colour work which figures as it is a minus red filter.
Rob,

I believe you mistyped 550nm for what should be 650nm for the typical end of panchromatic B&W film sensitivity.

I think there's also a problem arising from the Wratten vs. B+W and other filter designations. The Wratten 81(A,B,C) series are mild warming filters, the 85 series are stronger warming filters, and the 80 series are cooling color balancing filters, often used for daylight film under tungsten lighting. The B+W designations for the Wratten 80 series equivalents are KB filters, which don't go to zero transmission in red and do increase in transmission in the deep red to IR spectrum. However the B+W 081 is a different filter, and passes 10% at 600nm and fully blocks at 650nm and longer wavelengths. It doesn't have a secondary passband in the deep red or IR according to the curve in my 1982 B+W handbook.

Well, I just went looking for B+W curves on the web since I have no good way of copying from my 1982 B+W handbook. Looks like the curve for the 081 has changed a bit, passing more red and IR, but still not rising in that region. In any case, the 081 is certainly a stronger cutoff than a CC40C cyan from B+W. Others make stronger CC filters.

B+W curves are here: http://www.schneideroptics.com/pdfs/...sionCurves.pdf

The full handbook is here: http://www.schneideroptics.com/info/...dbook_Full.pdf

The 470 is missing in the new literature, but you might find "new old stock" at some dealers. The 470 wasn't a huge seller.

Lee

Last edited by lee l; 14th January 2009 at 10:30 PM.
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