Forte Polywarmtone FB slow?

Discussion in 'B&W: Film, Paper, Chemistry' started by naaldvoerder, Apr 11, 2004.

  1. naaldvoerder

    naaldvoerder Member

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    Hello forum,

    Recently I have started to print on Forte Polywarmtone FB semi-matt . I really like the semimatt texture and tone of this paper and i can do Lith on it too. The drawback is that it takes ages to take tone. I arrive at times over 2 minutes at 5.6 for 30x40cm print. Does anyone of you have the same experiance with this paper?
     
  2. ann

    ann Subscriber

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    It has a paper speed of 160 (if remembering correctly) and so it is about 3 stops slower. Check the spec sheet that came with the paper. FOrte recommends exposing changes ; as it has been some time since i have used that paper i am not a 100% sure if the additional time is 2.5 stops or 3. 2 minutes does seem a long time. What is the blub strength? I am assuming you are talking about exposure times for the print. My times are something like 40 secs for a 16 X 20 print at f 11, consender head.

    Toning time is going to depend on which toner and what diltuion ratio.
    With selenium 1:5 I am toning 5 minutes for completion.
     
  3. Donald Miller

    Donald Miller Member

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    A great deal of the exposure time that you are experiencing could very well be due to negative density. I am not sure if the JandC Polywarmtone paper emulsion is similar to the Forte that you mention...however I have experienced times of 4 minutes with a 200 watt bulb on my Durst 138S enlarger. In defense of the paper, the negative density was excessive, in my case.
     
  4. ann

    ann Subscriber

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    Good point Donald, the negatives i have been printing are in the "normal contrast" range.
     
  5. naaldvoerder

    naaldvoerder Member

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    Ann

    I'm using a 100 Watt halogeen light in a diffusor (colorhead) setup. Are there stronger halogene lights?
     
  6. ann

    ann Subscriber

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    you might want to check the specs for your enlarger. There are a wide variety of blubs available, however; they must match the specification of your enlarger.

    Am sure there is someone with more knowledge about electricity than I, but 100 watts for a color head seems small.

    A higher wattage would have a big impact on your exposure times.
     
  7. Donald Miller

    Donald Miller Member

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    The bulb in my 4550VCCEXLG is 250 watt halogen. However it is not as simple as simply installing a larger light bulb. The things to be considered in going to a larger bulb are:

    1. Cooling...increased wattage equates to more heat. Increased heat leads to fire considerations if proper cooling is not supplied.

    2. Power supply if your enlarger utilizes one. Most halogens used in enlargers are lower voltage lamps and consequently power supplies are responsible for supplying the proper voltage and they are sized according to wattage/amperage requirements.

    I agree with Ann's comment that a 100 watt lamp seems small.
     
  8. skahde

    skahde Member

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    Before you start to install halogen-lamps that may be to strong for the the lamphouse as well as the power-supply: what times do you have with other papers at what magnification? Is the mixing box made for the format you are enlarging? Is the lamp the right one for your head or did someone install "just something" that fits?

    BTW: PW is a suprisingly slow paper but IMHO worth the wait.
    best

    Stefan
     
  9. roy

    roy Member

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  10. naaldvoerder

    naaldvoerder Member

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    Stefan,

    The mixingbox is for 6x6. I have the 35mm also but i did not bother to change it. Never felt the need with other papers. I'll try and see if that brings in more light.
     
  11. noseoil

    noseoil Member

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    Which enlarger are you using? I wouldn't start swapping bulbs without a lot of research. As Donald said, the bulb is matched to the housing and power supply, so any changes may be a problem. The Omega 4x5 enlarger I use for all of my enlarging comes with a 260 watt bulb. It is possible that 100 watts is correct for a MF enlarger and a higher bulb rating would be needed for an enlarger of greater capacity.

    The question of negative density is also a good one. Are you exposing with a lot of highlight detail in this long exposure print, or is it a "normal" shot?
     
  12. ann

    ann Subscriber

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    The mixing chamber will absolutely effect times. You need to change to the correct one.

    And as we have all said, check the specs for your specific enlarger to find out what light source would be correct other wise you will create additional issues.
     
  13. Snapper

    Snapper Member

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    ...
     
  14. ann

    ann Subscriber

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    Snapper;
    I believe the instruction indiacte a 2.5 exposure factor.
     
  15. Doug Bennett

    Doug Bennett Member

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    I've used Polywarmtone, and compared to Ilford FB, it is quite a bit slower. My notes indicate that I was consistently using a 1 stop smaller aperture plus a slightly longer exposure time.

    Nice stuff, though, and really heavy paper stock is always sexy.[/i]