Minus Red Filter?

[jglass]

I want a strong filter that will darken a brilliant red object on B & W film. I think a Wratten 44A is a "minus red" filter. My searches tell me it's a cyan or blue-green flter. I'd like to get a 67mm glass filter.

Is there another filter I should be looking for; it does not have to be truly "minus red"

Any suggestions on a good primer (book or site) on filter use in 1) b & w film and 2) color film? I guess the best are A. Adams for b&w and Horenstein books on color. Any good discussions of filter fundamentals elsewhere?

Thanks.

 

[BrianShaw]

I always used a green filter for that purpose. It is not truly minus-red, but close enough and easy to find.

 

[BrianShaw]

p.s. Best primer I know of for filters is the B+W filter catalog, whcih is downloadable from the web --- Schneider web site.

 

[jeffreyg]

I have two B+W 67mm green filters. The 061 is dark green and has a filter factor of 3x. The 060 is light green and has a filter factor of 2x. I'm not sure what the equivalent is for a different brand. They both "darken" red with the 061 having more of an effect. Personally, I tend to use the lighter one more often to "lighten" foliage rather than "darken" reds.

http://www.jeffreyglasser.com/

 

[BrianShaw]

(deleted)

 

[BrianShaw]

Forget what I said... I had a brain glitch. Green filter is NOT #11. It is #61 -- the Wratten number. What was I thinking???

 

[Lee L]

Yes, the Wratten 44 and 44A filters are cyan (minus red) filters. I'll attach a graph of similar passband filters. My suggestion would be to buy the strongest cyan CC filter that you can find, as that's probably as close to a 44 or 44A that you'll find in stock these days. The green filters are also minus-blue, not just minus-red. The Wratten #11 in the attached graph is a yellow-green filter, not the darker #61.

I bought a 44A B+W filter in Germany in 1982. Within a couple of years it had gotten a terrible rough 'fogged' surface, visibly raised, rough to the touch, but not like any fungus I'd seen. I tried to return it under the Schneider US lifetime warranty, but they wouldn't honor that in the US since I'd purchased in Germany (where Schneider wasn't the distributor). It's the only B+W filter I've had trouble with aside from a circular polarizer that was replaced under warranty.

Lee

 

[brianmquinn]

With Efke 25 and 50 films going away what filter and film combinations going do you suggest for similar results.
Both of these films have low red sensitivity.

 

[Lee L]

Haven't had or seen in person a B+W 080 or 081 filter before. Looks like the 081 might be a fair substitute for a Wratten 44, and the 080 might be good for mimicking the discontinued Efke films (or some degree of cyan CC filter). B+W filter curves are at https://www.schneideroptics.com/pdfs/filters/FilterTransmissionCurves.pdf and the handbook is at https://www.schneideroptics.com/pdfs/filters/BWHandbookFull.pdf

Lee

 

[jim appleyard]

With Efke 25 and 50 films going away ... QUOTE]

I thought it was just the paper that were being discontinued?

 

[MartinP]

There is 'unofficial' information that the whole of the production facility will be closed as film is not enough to keep them going on it's own - basically they don't own the land (rental costs etc.) so the fixed-costs of the operation wouldn't reduce with the reduction in production. The end of the paper-line may be the end of Fotokemika too, unless there is some tiny vestige producing chemicals. See the other thread here, the one on RFF etc. etc.

 

[Doremus Scudder]

Back to the original question:

If you want to darken reds, any filter that doesn't pass red will do the job. A sharp-cut green or blue filter will do the job, but have different effects on other colors in the scene.

I'd start by using some of the more common blue and green filters; the 44 filters are getting harder and harder to find and, as far as I know, are now only available as Wratten gels. The B+W 081 and 080 seem to no longer be available. I've been trolling for one in 67mm size for some years now and can't seem to find one.

I do have 44 and 44a filters, which I use for approximating the look of orthochromatic film using regular pan film. I also use an 80B for this from time to time with good results. It passes some red, but does darken it quite a bit. If you've got one of these laying around, you might give it a try.

Best,

Doremus

www.DoremusScudder.com

 

[Lee L]

It's definitely true that the Wratten 44, 44A, B+W 080 and 081, and other cyan filters are extremely rare in the US, and have been for a very long time, at least since the 70's in my experience. That's one reason I purchased mine in Germany in '82.

I did see yesterday that Calumet has a 40 or 50 cyan CC filter in a square plastic filter, and the 80A and 80B may be the best chance these days, but even those are becoming rare in the days of digital specification of color temperature. After posting, I noticed that at least in the US, dealers are now listing the B+W 080 and 081 as discontinued (the place I normally look was offline when I posted). Sometimes that means 'no longer made', sometimes 'no longer imported' by the distributor. I'd suggest that anyone looking for any kind of minus-red function in a filter search thoroughly now and buy now.

Lee

 

[jglass]

Thanks for the help folks. I guess this is why I've had trouble finding this. So, if I don't want to also darken blue sky in the image, I would use Wratten 44, 44A, or B+W 080 or 081, correct? Not green.

Don't you guys have any luck on auction sites for stuff like this, or not? I'll be looking myself so one more to compete with. Thanks.

 

[BrianShaw]

If you can't tolerate an alteration of blue sky then I think you are correct. I've never been that constrained.

Have you thought about calling the folks at Lee Filters and asking them what they recommend and can supply? They have a cool feature on their website that shows their offerings and the spectral characteristics. Or calling Rosco? I've used Rosco gels as filters and while not ideal that works too... and inexpensively.

 

[jglass]

Good idea, Brian. This is a very special use, and a cheap gel might work

 

[ME Super]

additive vs. subtractive color

White = Red + Green + Blue. Using algebra, White - Red = Green + Blue. We call Green + Blue "cyan." So a cyan filter is indeed "Minus Red" and should pass green and blue mostly unaltered but block the red.

Reversal film works in exactly this "minus red, minus green, and minus blue" fashion. The red-sensitive layer contains cyan dye couplers, the green-sensitive layer contains magenta dye couplers, and the blue-sensitive layer contains yellow dye couplers. When the developing process is complete, there is cyan dye where the red light wasn't, magenta dye where the green light wasn't, and yellow dye where the blue light wasn't.

 

[senderoaburrido]

Anyone ever get a line on minus-red filter purchase in the modern day?

 

[AgX]

Minus-red only is available as CC filters. For stronger effect you either have to stack them or use both a Green and a Blue filter.

 

[Doremus Scudder]

Minus-red only is available as CC filters. For stronger effect you either have to stack them or use both a Green and a Blue filter.

You can still get #44 filters as Wratten gels (note, these are not cyan CC filters, but a "minus red" filter). They tend to be expensive new, but I've picked up some used on eBay for not too much from time-to-time.

As mentioned, you can stack blue and green filters, but this will not necessarily get you the exact same transmission as the #44. I just looked through a #11 and an 80A filter stacked and the result is much more green than cyan.

As I mentioned in my (much earlier) post above, I have pretty good luck with an 80A filter for achieving an orthochromatic look. Try it and see if you like it. An 80A is originally an compensating filter for using daylight film under tungsten lighting and attenuates red a great deal.

Best,

Doremus

 

[AgX]

I stand corrected. I see that even Kodak still lists type 44.