Where are the contrast filters supposed to go?

Discussion in 'Darkroom Equipment' started by Andrey, Jan 29, 2008.

  1. Andrey

    Andrey Member

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    I'm trying to hunt down some 6 inch VC filters, but have been offered the small 3.5 inch sheets.

    Is it ok to place them between the bottom condenser lens and the negative? Will that make all of the scratches on the filters visible because of the proximity?

    Or should they go above the first condenser lens?

    I don't want to save a couple of bucks and have artifacts in the prints.

    I am using the big D2 variable condenser.
     
  2. Ian Grant

    Ian Grant Subscriber

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    That's the best place, above the condenser is far too hot and will burn them. Scratches shouldn't show up below, but my one set lasted about 20 yrs with no scratches anyway, as long as you careful they don't mark.

    Ian
     
  3. mark

    mark Member

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    If the filters are scratched now get new ones. If not scratched now, be nice to them, and under the lens is the best place for them. Makes it easier to split filter.
     
  4. Andrey

    Andrey Member

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    Under what lens? The lower condenser?

    Or do you mean under the projection lens (el Nikkor or similar)

    Just by logic, there shouldn't be anything between the negative and the paper, unless it's multicoated and made of optical glass.

    I also heard that scratches on the lower condenser do show up in prints. Wouldn't putting a scratched filter in there do the same thing?
     
    Last edited by a moderator: Jan 29, 2008
  5. Michel Hardy-Vallée

    Michel Hardy-Vallée Membership Council Council

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    Under the lens is the worst place for filters that could be slightly damaged. It's OK if filters are A) gelatin and B) in good condition, but otherwise, it's much safer to put them between the negative and the condenser.
     
  6. Andrey

    Andrey Member

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    ok, I want to know what the manual says. I bet it says to put filters between the lamp and the top condenser lens.

    Otherwise, why would anybody make 6 inch filters?
     
  7. Michel Hardy-Vallée

    Michel Hardy-Vallée Membership Council Council

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    Ilford makes 6inch VC filters. Very useful when you are printing 4x5 negatives.

    Isn't there a filter tray somewhere on the D2 ?
     
  8. Andrey

    Andrey Member

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    I can think of a couple of places where I could stick a filter. :D

    I can put it above the top condenser lens. I think that's the right way as it is before ALL of the optics.

    I can put it right on the negative carrier, above the negative. It doesn't seem right, but if the filter is 1mm above the neg, then it won't show up.

    Or I can stick it in anywhere between the neg and the paper. And that's one of the carnal sins of photography because the image gets degraded.
     
  9. rwyoung

    rwyoung Member

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    Depends on the D2. Mine doesn't have a filter drawer. But sometimes I think it may have been built up from spare parts...
     
  10. Michel Hardy-Vallée

    Michel Hardy-Vallée Membership Council Council

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    Well, the condenser are not exactly part of the image-forming optical system. Their function is to "equalize" the beam of light that comes from the bulb. The bulb is a small, widening light source, and the condensers make it a large, more rectilinear light source.

    So here's my theory: if you put the filters above the condensers, they will be unequally lit by the bulb, most importantly they will suffer from more direct heat and fade quicker. If you put them below the condensers, then you will light them with a more even source of light (i.e. more even fading over time), and the glass will protect a little bit your filters from the heat.

    But anyway, I'm sure if someone really made the test, he would come up with a 1% fading difference over a period of 20 years, give or take 0.5%... So just do what you want, and if it doesn't work, try something else!

    Good printing!
     
  11. 23mjm

    23mjm Member

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    I used a enlarger for a short time that didn't have a filter holder above the neg. So I carefully placed the filter on the neg carrier above the neg. I never had a problem, the filter didn't touch the neg, I did check for that. It also never got hot.
     
  12. John Koehrer

    John Koehrer Subscriber

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    If you're using the D2V with the movable condenser The filters go in the same drawer as the variable condenser. If the older D2 (not V) you need to fabricate something. Putting the filters directly on top the neg carrier is asking for scratches. Putting them above the condenser is asking for rapid fading or possibly melting.
    Use the smaller filters beneath the lens if you don't have th V model
     
  13. mark

    mark Member

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    Hence the reason I said get new ones if they are damaged.
     
  14. Andrey

    Andrey Member

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    It says D2, but I do have the variable condenser head.

    Thanks.
     
  15. Maris

    Maris Member

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    I put multigrade filters under the lens and they work just fine. In theory putting anything between the lens and the photographic paper should degrade the image but I checked.

    The easiest check was to focus the negative with a grain focuser, filter in and filter out, and compare the view. In both cases I saw sharp, clear grain and if every grain in the negative is imaged onto the enlarging paper then that's as sharp as you can get.

    Checking for flare was done by enlarging a good grade #2 negative without a filter and then with a #2 filter. Fine white lines on a dark background and fine dark lines on a light background were compared in both cases. I could not see a convincing difference.

    Smudged, scratched, or dusty filters would probably cause a difference but the position of the filter in the bright enlarger beam immediately under the lens makes these defects glaringly visible. Cleaning or replacing a bad filter is no chore compared to the alternative.