VC Light Source - Exposures Too Long

Discussion in 'Darkroom Equipment' started by MurrayMinchin, Jun 26, 2005.

  1. MurrayMinchin

    MurrayMinchin Membership Council Council

    Messages:
    4,196
    Joined:
    Jan 9, 2005
    Location:
    North Coast,
    Shooter:
    4x5 Format
    I'll try to make this brief, but I think the path to my current situation is relevant. I went 4x5 in the original Brilliant graded paper days, exposed with cold light. When they brought out Brilliant II they changed the contrast, but I found I could keep my Normal negative development time by using Galerie graded paper. This means I have "rich & full" negatives.

    When I switched to VC I got a Zone VI VC head that gave HEINOUS contrast on a host of papers with the Soft and Hard light at equal settings. To achieve a normal contrast print (on Multigrade IV) with the VC lights at equal settings, I had to place a 40YCC filter below the light source and switch to a paper developer similar to Ansco 120. At about the same time I started using sharp and unsharp masking techniques which require a glass negative carrier. The green cast of the glass in the negative carrier also lowered the contrast. I know, I know, why did I order this light if I didn't intend to use Zone VI VC paper? I was seduced by marketing. D'oh...

    Now I have a light source reduced in intensity by the 40YCC filter, two sheets of glass, and base exposures sometimes increased by as much as 25% when a Contrast Reduction Mask is used because of the masks film base + fog. In real life this means an 11x14 base exposure at f8 (f5.6 is wide open) can be 55 seconds. This is with the "brightness" control maxed out at 10. I'll need an alarm clock to wake me up when the exposures are done for 20x24!!!

    It's also very important to the way I work that I know when both lights are stabilized. Have any ideas / options? We are financially inadequate and this was a HUGE investment for us, so please keep this in mind. To date I've mostly been running endless tests and making prints at 5x7 (which is affordable), so the exposure times and apertures were reasonable. I do have a set of 6x6 Multigrade filters from decades ago, so I'm open to any and all Do-It-Youself suggestions as well. Thanks.

    Murray
     
    Last edited by a moderator: Jun 26, 2005
  2. photobackpacker

    photobackpacker Advertiser Advertiser

    Messages:
    430
    Joined:
    Mar 21, 2005
    Location:
    Minnesota
    Shooter:
    4x5 Format
    Hi Murray:

    Did you purchase this unit new or used. If used, describe the unit. The ZoneVI has changed over the years and they are not all the same unit.
     
  3. Loose Gravel

    Loose Gravel Member

    Messages:
    921
    Joined:
    Feb 28, 2003
    Location:
    Santa Barbar
    MM

    I don't know about the Z6 light source, but I did have an Aristo VC and heard many times that is was supposedly brighter than a Z6 and it was SLOW. I switched back to a V54 tube from Aristo and use a MetroLux for stability. It is about 2-3 stops faster. I print with Bergger VC CB and use the Ilford filter below the lens. They don't hurt the image quality one bit and they work just fine.

    I like my exposures around 10 sec and with 8x10s or 11x14s from 5x7 this is easy, still several stops down. Never made a 20x24, but you can do the math and the answer is it would be much shorter.

    Hope this helps.
     
  4. MurrayMinchin

    MurrayMinchin Membership Council Council

    Messages:
    4,196
    Joined:
    Jan 9, 2005
    Location:
    North Coast,
    Shooter:
    4x5 Format
    The paper work it came with calls it a "Zone VI Variable Contrast Cold Light Head for Beseler 4x5 MX and VXL series". I got it new in 2002, then health and Life issues got in the way and I stayed out of the dark for a while...

    In my usual long winded convoluted way, I was trying to find out if somebody else has solved this problem, and what they did to solve it, or if somebody knows of a light source more suited to my needs, or maybe even what bulbs could be suggested to build my own.

    Murray
     
  5. MurrayMinchin

    MurrayMinchin Membership Council Council

    Messages:
    4,196
    Joined:
    Jan 9, 2005
    Location:
    North Coast,
    Shooter:
    4x5 Format
    Thanks, I'll check into it.

    I've found a definition of tungsten light being between 2700 and 3500 degrees Kelvin. Anybody know what Ilford uses as a standard?

    Murray
     
  6. photobackpacker

    photobackpacker Advertiser Advertiser

    Messages:
    430
    Joined:
    Mar 21, 2005
    Location:
    Minnesota
    Shooter:
    4x5 Format
    I printed with an earlier version of the very head you are talking about. I too had problems with the long exposure but I never had any difficulty with too much contrast. If you are getting exceedingly high contrast at a neutral setting, I think you may have a problem with one of the tubes.

    Call Calumet and talk to one of their technicians. I ended up negotiating an exchange with them but my issue was with the earliest design. These units were not well stabilized and you couldn't count on consistency from one print to the next. My understanding is that this problem was been solved and this shouldn't be an issue with one purchased new in 2002. You might ask about this to ensure this is not part of the problem.

    There should be no need to buy a specific brand of paper with this head - nor should you need to add a 40y filter. This was a VC solution for the original graded paper cold light heads and it didn't work very well with them either. If your contrasts are off the wall, there is something wrong with the unit.

    Good Luck. A tip for dealing with Calumet: keep a diary of every phone call, every person talked to and what was said. You may need a strongly worded letter to their president to get satisfaction and these notes will help.
     
  7. lee

    lee Member

    Messages:
    2,913
    Joined:
    Nov 23, 2002
    Location:
    Fort Worth T
    Shooter:
    8x10 Format
    Why not just split filter print laying down you soft light (green) first then using the blue light to control the contrast?

    agree you dont need the 40y for any reason

    contact Calument Photo Blaughn has given good advice imo

    lee\c
     
  8. Bob F.

    Bob F. Member

    Messages:
    3,984
    Joined:
    Oct 4, 2004
    Location:
    London
    Shooter:
    Multi Format
    The document on the Ilford site on Contrast Control has a short section on cold light heads and recommends a 40Y filter with the Arista W45 lamp (not terribly helpful I know but at least suggests you are correct in using one) - it also shows what happens to the contrast grades with that lamp.

    MGIV is a very fast paper at ISO P500 with no filters, so a faster paper is not really a practicality - don't try Forte Polywarmtone (P160): you'll need a calendar, not an alarm clock :sad: ...

    Bob.
     
  9. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    When I switched to VC I got a Zone VI VC head that gave HEINOUS contrast on a host of papers with the Soft and Hard light at equal settings. To achieve a normal contrast print (on Multigrade IV) with the VC lights at equal settings, I had to place a 40YCC filter below the light source and switch to a paper developer similar to Ansco 120. At about the same time I started using sharp and unsharp masking techniques which require a glass negative carrier. The green cast of the glass in the negative carrier also lowered the contrast. I know, I know, why did I order this light if I didn't intend to use Zone VI VC paper? I was seduced by marketing. D'oh...

    Now I have a light source reduced in intensity by the 40YCC filter, two sheets of glass, and base exposures sometimes increased by as much as 25% when a Contrast Reduction Mask is used because of the masks film base + fog. In real life this means an 11x14 base exposure at f8 (f5.6 is wide open) can be 55 seconds. This is with the "brightness" control maxed out at 10. I'll need an alarm clock to wake me up when the exposures are done for 20x24!!!

    It's also very important to the way I work that I know when both lights are stabilized. Have any ideas / options? We are financially inadequate and this was a HUGE investment for us, so please keep this in mind. To date I've mostly been running endless tests and making prints at 5x7 (which is affordable), so the exposure times and apertures were reasonable. I do have a set of 6x6 Multigrade filters from decades ago, so I'm open to any and all Do-It-Youself suggestions as well. Thanks
    .

    It isn't gospel that you have to have both lights at equal settings. What you are doing by adding 40 units of yellow (minus blue) is that you are adding neutral density. Neutral density will decrease the passage of light to the easel. You could accomplish the same thing by increasing the amount of green in your initial settings. You might try using a ratio of 6 soft (green) to 4 hard (blue) and if that is still too harsh then increase the ratio more still. By all means get rid of the yellow filter. Ilford is making that recommendation for a single lamp Aristo cold light head and not a two lamp VC head. The effects of the glass in the negative carrier is not nearly the major factor that your yellow filtration is.
     
  10. Keith Tapscott.

    Keith Tapscott. Member

    Messages:
    1,426
    Joined:
    Jun 11, 2005
    Location:
    Plymouth. UK
    Shooter:
    Multi Format
    Which enlarger do you use? It may be worth switching to an Ilford Multigrade Head. Contact Ilford and see if the latest Multigrade 600 system is compatable with your enlarger.
     
  11. MurrayMinchin

    MurrayMinchin Membership Council Council

    Messages:
    4,196
    Joined:
    Jan 9, 2005
    Location:
    North Coast,
    Shooter:
    4x5 Format
    Thanks to all of you. Your suggestions have been...enlightening!

    This is NOT the way I thought this would play out!!! I had assumed the light was behaving as it should. There are many benefits to living in relative isolation (it's a 1000 mile drive to the nearest photography gallery, or store that sells large format film) but not having peers, or others around to ask questions and learn from, isn't one of them.

    Thanks a bunch...(I'm going away now to question Calumet and Google / APUG.search my a$$ off)

    Murray