variable contrast printing

[steve hartsfield]

Sorry, this question has probably be discussed before, however I am new getting back into LF photography. My enlargers are Besseler 45MX2 and Omega C67. They have zone 6 cold lights in them from the mid to late 1980's. I understand that I will not get decent prints on variable contrast paper. Does anybody know where to find vc lamps for these enlargers (diffusion) and do vc lamps work correctly on graded papers? Aristo is out of business!!! Calumet says tough luck! Is this the end of my darkroom (other than using the limited supply of graded papers)?

I have invested in vc paper and did not realize my cold lights would be incompatible.

Thanks for you help.

[Eric Woodbury]

Aristo is gone? That's bad.

I'm using the latest Aristo V54 grids. Very bright. You can hit all the contrasts with one of these and filters. You might try a dichroic color head. Some folks here like those very much. The coldlight VC are attractive, but not very bright. YMMV

[Peter Mounier]

I have a Beseler Dichro 45s color head I will sell if you're interested.
$400.00 plus shipping.
Peter

[SAShruby]

Hmm,

I regularly print Ilford Multigrade with cold light head using split printing and get decent prints using this combination.

Why do you think you won't get decent prints?

[steve hartsfield]

I read on photo.net that printing on vc papers with a cold light would result in constrasty images. I guess I need a V54 lamp for my zone 6 head. Pardon my ignorance, what is split printing?

[steve hartsfield]

I will consider your offer, but will try to find another solution first.

[SAShruby]

Hey Steve,

Split printing is a process of applying two set of exposures, one through green filter which controls the details and one through blue filter which controls the contrast. By having different times per each filter I believe you can set finer grades than with filter grades. This process allows me to look at the print with a table of 6x6 exposures with different grading and use only two-three sheets of paper before making decision which times I use to make a base exposure. (actually in reality I don't go more than 3x3, I use densitometer to read the density range of the negative and then decide the ties for the contrast). When dodging or burning, it would give you an advantage to adjust contrast as well as details with more control.

If you use local search engine, you might find few very good threads on this topic.

[ic-racer]

There is likely nothing wrong with your cold cathode tubes for MG printing. Have you tested it? If you don't want it I'll take it :) :) Now that Aristo may not resurface as a supplier, those older W45 tubes (or similar) will be worth keeping!

Ilford explains in detail how the W45 can be used for excellent results with their MG filters and papers. I use a W45 and can attest that it works fine (http://www.largeformatphotography.info/forum/showpost.php?p=447907&postcount=103).

http://www.ilfordphoto.com/Webfiles/2006130201152306.pdf

You may not have a W45, but I'd read that Ilford document and try what you have. I'll bet it works fine. If you need an 'extra' yellow filter for testing (as it explains in the article), consider using the '00' in combination with another filter in the pack.

Since light output changes with exposure duration (http://www.largeformatphotography.info/forum/showpost.php?p=380768&postcount=63),I'd stay away from split printing.

[SAShruby]

Or buy Zone VI Compensating Timer. $200 and up

[steve hartsfield]

I have polymax (Kodak) filters, they are shades of yellow and magenta only. Where do I find these filters (blue, green, etc.)?

[Donald Miller]

I have polymax (Kodak) filters, they are shades of yellow and magenta only. Where do I find these filters (blue, green, etc.)?

You can use the filters that you have. Magenta is the harder filter and will increase contrast. Yellow is the soft filter. You adjust contrast by varying the amounts of each to the other. One of my enlargers with the VCCE head uses the same colors.

Donald Miller

[Brian Ellis]

You can use any light source to print graded papers, the color of the light makes no difference in the look of the print. Graded papers are a little more sensitive to bluish light and so that type of light will result in shorter exposure times. But the print won't look any different.

[domaz]

I'm using the older Aristo cold light head with a Besler 45. I don't have trouble changing contrast grades. Supposedly putting a yellow filter in the light path can help with contrast issues as well. I would say try it- and if you are picky enough to notice the contrast issues then deal with it at that time.

[ic-racer]

I have polymax (Kodak) filters, they are shades of yellow and magenta only. Where do I find these filters (blue, green, etc.)?

It is more of a concept. In the Additive system, If you had a blue and green bulb, you would turn up the blue light for more contrast and turn up the green one for less contrast. Or in split printing you can think of it as adding extra green or blue time.

With filters, you are always decreasing the light intensity, so it is called subtractive. So, to SUBTRACT green from the lightsource (and get more contrast) you swing in the magenta filter. It blocks its opposite color, which is green. Then to subtract blue (to make the print less contrasty) you swing in the yellow filter (which blocks blue).


But, ADDITIVE and SUBTRACTIVE are just concepts, and in actual use, the paper will respond fine to a filter set composed of either yellow/magenta or blue/green.

[nolindan]

The yellow/magenta filters are - from the paper's viewpoint - identical to green/blue.

Since paper can't see red and we can, the standard VC filters also pass red light, making it easier to see the image for dodging and burning. If not for the red component it would be very hard to see the image, especially at the high contrast grades where the color would otherwise be a very deep dark blue.

You can look at the system as either additive or subtractive...

Yellow = red light + green light, or removes blue
Magenta = red light + blue light, or removes green

It is possible to use standard Rosco filter gels for VC printing. Rosco gels cost around $6 a sheet for the 20x24" size. Google for more information.