cold light heads & vc paper

[temujin]

hello all - i am planning on purchasing a cold light head for a home darkroom. i use mostly graded papers these days, but i sometimes use vc when i want a matte paper (as i am not aware of any matte or semi-matte graded fiber papers). my question is - what approximate contrast grade should one expect to get from a vc paper when printing with a cold light head? also, i have read that some cold light heads require a yellow filter for use with vc papers. is this true only for older cold light heads, or also for modern models such as current aristo heads? thanks.

 

[Michel Hardy-Vallée]

I have an old Zone VI cold light head for graded papers (blue light only) and the correction I use is a layer of CC40Y filter. Using multigrade filters on Ilford papers I have normal grades.

 

[jstraw]

I use the same filter now but plan to buy an Aristo V54 lamp.

 

[Jim Noel]

As JStraw indicates, the secret is the lamp. If you buy straigt from Aristo talk with them and tell them you want the lamp which works best with both graded and MG paper.

 

[George Collier]

Aristo's V54 lamp is designed for VC as well as graded, it has a cyanish cast. I use it successfully with Forte and Ilford VC. In fact I have to find a replacement for Forte now..grrr..
My experience is - works well, but consistency of exposure, and linear filtration behavior between grades doesn't happen, at least with Ilford filters, even with Ilford paper. Much testing of exposures when testing for the right grade, expecially with split filter printing, but worth the trouble, imho.
Also, and Aristo will tell you this - the dual lamp version of their product, even though it's more convenient, requires more exposure than the filter/drawer version, which is the one I have. The drawer is up above the diffusion disc below the bulb, so it's out of the image path. The dual lamp version also costs a pretty penny more too.
"And another thing" - if you get the drawer version you may want to buy an extra drawer, makes things go much faster for split printing.
See here for their heads, there are 3 - http://www.aristogrid.com/prod02C.htm.
No I own no stock, I just think they have a good product for the cash.

 

[David A. Goldfarb]

My head (Aristo HiD for Omega D-series) has a V54 lamp, and I don't have the consistency issues that George is describing, which I suspect are due to the ramp-up time of the bulb. I also have a Graflarger head with an old-style bulb and it definitely has consistency problems.

I use mostly graded papers these days, but for VC I just put the filter between the head and the neg carrier, and that works. The filter is far enough from the neg that it's not in focus. On an Omega-D the head just rests on the neg carrier, and the weight of the head holds it closed.

Some cold light heads (like the Aristo on my Omega D-II) have a separate heater circuit that stays on all the time, so that once it is warmed up it gives pretty consistent exposures.

You can also use a closed-loop timer with a probe, like a Metrolux (which I do) for perfect consistency, which I highly recommend. I don't know how I got along without it. If I'm doing something like a run of postcards for the postcard exchange, I can set it for a very short exposure time, like 1.6 sec., and I have no problem producing 40 identical prints.

 

[Curt]

Who makes the Metrolux? Is it a Calumet made and sold item?