cold light filter question

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From reading the archives it seems I should use yellow cc40 filter to correct the light coming from my cold light head, to use VC filters. If I buy a set of color correction filters for color printing, will it include that filter? Should I just buy one filter, and if so, where?

-- Bruce Appel (appelgate@aol.com), February 13, 2001

Answers

I have another and cheaper source: cinematography (movie) supply houses. The Rosco company (among others) makes bulk CC filter material. I paid $5 for a square yard. This was a lot cheaper than $35 for a wratten gel. Try searching their website (www.rosco.com) for a local dealer or look in the yellow pages.

Cheers,

Duane

-- Duane K (dkucheran@creo.com), February 13, 2001.


I've not used a cold-light head, but I would first check with the head's mfr as to the need for this cc40 filtration. Also, I'd buy a set of VC filters and test to see what contrast range they produce without any other filtration. You might get all the contrast control you need. Even if it turns out that you do need a cc filter, you will also need the VC filters if you use VC paper, so the money for VC filters will not be wasted.

-- Keith Nichols (knichols@iopener.net), February 14, 2001.

You might just want to try the filters without any correction first. My experience has been that this is the best route to go. The big drawback will be that the actual grade numbers won't really correspond to much anymore. Like a grade 0 filter might really be the same as a grade 2. This all depends on what your setup is like, so making some ringarounds with a small step wedge might show you which ones are working the best. The only time you should need the cc filter, would be for trying to lower the contrast past a grade 2 or so. But, with split filtered printing, you might not need it all. Yeah, a "real" wratten filter will be sort of expensive too. You might want to just give a try first. Good luck.

-- DK Thompson (kthompson@moh.dcr.state.nc.us), February 14, 2001.

One other thought about the cc filter. Depending on where you intend to place, i.e. under your light source, or on the rear element of the lens, might be a factor into the quality of the filter. Wratten filters are generally considered optically "pure". A rosco cinegel is usually used for light sources, the same goes for the CP filters you'd get for color printing. Hope this helps.

-- DK Thompson (kthompson@moh.dcr.state.nc.us), February 14, 2001.

In the past I have done split filter printing with a blue and green filter. While I got some nice results, it was real hard to hold the contrast down, and a lot of work. Split filter printing, while a great technique, is not something I want to have to do for every negative. I am hoping that with a yellow correction filter I may be able to hold the contrast down and use standard filters.I don't really care if the filters respond differently than they are marked, as long as they are consistent. Another thought I have had is maybe my technique is all wrong. I would make a test strip with the blue filter, finding the minimum exposure to give me a saturated black. Then i would do another test giving this exposure first, then swithing to the green filter, do another test strip to get the highlights where I want them. Would it make any difference if I reversed the procedure and did the green filter first? In other words, nail down the highlights before worrying about the blacks? Still a lot of work for negatives that don't need it. It would be much simpler to be able to use standard filters.

-- Bruce Appel (appelgate@aol.com), February 14, 2001.


Bruce, that's pretty much the way I've done it. I usually go for the shadows first, but I've done it both ways. I don't really think it matters. It is a pain sometimes, but I think unless you have some really contrasty negs., that you should be able to get by with just using one filter. You could always get the cc filter to have just in case you needed it. I always thought that using a cc40y was just "sucking" the brightness out of the lamp, even with a high intensity head. Sometimes I like to keep some graded paper around for when all this stuff fails...but that's not too often. If you use an Aristo head, you might want to look into their new tube, I think it's a V54 or something like that, I can't remember. When I made these little contrast ringarounds, I really got a good idea of how different papers responded to the cold light. I just used a Stouffer projection step wedge, nothing too fancy. Good luck.

-- DK Thompson (kthompson@moh.dcr.state.nc.us), February 14, 2001.

You can buy the ccy filter by itself. This will cut down your light output significantly. Think of using Dr. Beers Developer. This is a multicontrast developer that you add more or less of part B to fine tune your contrast chemically! Just another work around I have done over the years. Cheers

-- Scott Walton (f64sw@hotmail.com), February 14, 2001.

Scott, are you mixing this up, or just using something like a combo of Selectol-Soft and Dektol?

-- DK Thompson (kthompson@moh.dcr.state.nc.us), February 14, 2001.

You put the yellow filter directly under the light source, above the negative, and never worry about it again. So, it doesn't need to be optically clear in a printing filter sense. I too use a Rosco gel, I think it was called Straw, and works great. Makes the cold light match the tungsten bulb exactly.

-- E.L. (elperdido65@hotmail.com), February 15, 2001.

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