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  1. #11
    L Gebhardt's Avatar
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    Quote Originally Posted by Donald Miller
    The ideal conversion, I would think, would be to use a point light source or even the high wattage and low voltage halogen conversion that Durst Pro has developed and then passing this light emission through a set of dichroic filters that would be incorporated in the area of the filter drawer. Shouldn't be too difficult to accomplish.
    How would you do this? The dicroic filters would need to be variable across the entire filter. In a color head they just move more and less of the filter into the light before it gets mixed in thr mixing box. The Ilford heads use two separate bulbs and adjust the intensity of each to vary intensity of each before the mixing box. It would be fairly easy to create a small mixing box to put above the condensers to act as a more point source.

  2. #12
    roteague's Avatar
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    Quote Originally Posted by Donald Miller
    Is this the dichroic version (color head)? If so you should have no problems printing variable contrast materials. It could be that the 4550 LPL baseboard would replace the missing one. If so they are pretty expensive...something around $450.00 is what was quoted to me.
    I pulled it out last night, it is a LPL 4500II, and yes it does have a color head. The baseboard should expensive, but one of these enlargers new is over $2000. I noticed on Calumet that there was an optional wall mouting bracket for the LPL series, which I am going to see if I can find. If not, then I will look for a baseboard.

    Thanks for the feedback,
    Robert M. Teague
    www.visionlandscapes.com
    www.apug.org/forums/portfolios.php?u=2235

    "A man who works with his hands is a laborer; a man who works with his hands and his brain is a craftsman; a man who works with his hands and his brain and his heart is an artist" -- Louis Nizer

  3. #13

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    Quote Originally Posted by L Gebhardt
    How would you do this? The dicroic filters would need to be variable across the entire filter. In a color head they just move more and less of the filter into the light before it gets mixed in thr mixing box. The Ilford heads use two separate bulbs and adjust the intensity of each to vary intensity of each before the mixing box. It would be fairly easy to create a small mixing box to put above the condensers to act as a more point source.
    The way that I would do this would be to begin with what Durst Pro has done with their conversion using the 1200 watt halogen lamp. In fact, even though it is expensive at $865.00. I might buy their conversion kit. Next I would buy a set of the physically largest dichroic filters that Durst or even Omega use in their color enlargers in the Magenta and Yellow spectrum. I would design an individual adjustment for each of these colors from the 0 to 200 units that they provide. I would try not to use a mixing chamber of an appreciable size since to do so would eliminate the benefits of a point light source. I think that in using a point light source no mixing chamber would be required since the lamp arc is such small dimension that the light path through the filter and any possible inaccuracy of the filter value would be on no consequence.

    Why would one consider this type of a conversion? For myself, I think that the point light source would have definite benefits over a diffusion source enlarger. I have found that, even though I have three diffusion enlargers along with three condensor enlargers, that the condensor enlargers do provide enhanced local contrast over the diffusion enlargers. I have found, in my experience that the local contrast lost in the use of a diffusion light source enlarger is unrecoverable at some latter point through any printing manipulations.

  4. #14
    L Gebhardt's Avatar
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    Quote Originally Posted by Donald Miller
    The way that I would do this would be to begin with what Durst Pro has done with their conversion using the 1200 watt halogen lamp. In fact, even though it is expensive at $865.00. I might buy their conversion kit. Next I would buy a set of the physically largest dichroic filters that Durst or even Omega use in their color enlargers in the Magenta and Yellow spectrum. I would design an individual adjustment for each of these colors from the 0 to 200 units that they provide. I would try not to use a mixing chamber of an appreciable size since to do so would eliminate the benefits of a point light source. I think that in using a point light source no mixing chamber would be required since the lamp arc is such small dimension that the light path through the filter and any possible inaccuracy of the filter value would be on no consequence.
    I still don't understand how if the filters are below the lightsorce how you will adjust them. In the only color enlarger I have played with, Omega D5, the filters partially move in front of the light source. If this happens without a mixing box you will see the filter with the condensers. Is there something I am missing?

    Quote Originally Posted by Donald Miller
    Why would one consider this type of a conversion? For myself, I think that the point light source would have definite benefits over a diffusion source enlarger. I have found that, even though I have three diffusion enlargers along with three condensor enlargers, that the condensor enlargers do provide enhanced local contrast over the diffusion enlargers. I have found, in my experience that the local contrast lost in the use of a diffusion light source enlarger is unrecoverable at some latter point through any printing manipulations.
    I agree, which is why I am curious. I currently own two D5XLs with three heads (condenser, Ilford, and Chromega). I haven't used the condenser head in a while, but I did notice a change in my prints when I stopped. I have not tested the diffusion against the condenser and seen if I could product the same look with each however.

  5. #15

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    Quote Originally Posted by L Gebhardt
    I still don't understand how if the filters are below the lightsorce how you will adjust them. In the only color enlarger I have played with, Omega D5, the filters partially move in front of the light source. If this happens without a mixing box you will see the filter with the condensers. Is there something I am missing?
    In the Durst 138S enlarger the filter drawer is situated immediately in the front of the lamp. The light is then transmitted to a front surface mirror and reflected downward through the condensors. The color enlarger that I have used has dichroic filters that increase very linearly from a small value to a larger value. Thus they are configured more as a variable intensity color "wheel" then a single value that is adjusted in or out of the light path. My thoughts are based on this "variable wheel" model. It is this type of a dichroic filter the I would place into the light path.

    Quote Originally Posted by L Gebhardt
    I agree, which is why I am curious. I currently own two D5XLs with three heads (condenser, Ilford, and Chromega). I haven't used the condenser head in a while, but I did notice a change in my prints when I stopped. I have not tested the diffusion against the condenser and seen if I could product the same look with each however.
    I stayed away from condensor sources for years because of all of the horror stories that AA and others promulgated. I am happy to relate that here has been no single thing that has contributed more to the improvement of my prints then the condensor light source. Of course all should choose their own direction in this regard.

  6. #16
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    Don, if I understand your post, are you saying that filters similar to a graduated neutral density filter exist in M&Y? If this is the case, it seems that a mechanism for adjustment and calibration would be easy enough to make in a home shop. Calibration would be the most difficult part to accomplish, but it would be a question of trial & error against a known standard which already exists from a diffusion enlarger with a color head.

    Second, it sounds as if you are comparing the prints from a variable head with mixing chamber to a condensor enlarger, as the different results found between films developed with PMK and ABC. The diffusion head is a softer image, while the condensor gives the true clarity and sharpness which is inherent in a good negative with high acutance.

  7. #17

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    Quote Originally Posted by noseoil
    Second, it sounds as if you are comparing the prints from a variable head with mixing chamber to a condensor enlarger, as the different results found between films developed with PMK and ABC. The diffusion head is a softer image, while the condensor gives the true clarity and sharpness which is inherent in a good negative with high acutance.
    Yes, that would be a good comparison. What I have found is that local contrast is evident on a print in which the light bundle is sharply collimated as in a condensor enlarger; that furthermore a diffusion light source compromises this local contrast because the light is scattered as it enters the negative interface. That when one fails to realize this local contrast and sharpness that it can not be captured at a latter step or even in increasing contrast (for instance) with a diffusion light source. This is evident to me today because diffusion light sources do not exhibit the need for print spotting to the degree that condensor sources do. I believe this is due to the diffusion light source light scatter "washing" the spots in the diffusion light source. This "washing" comes at a price...that price is reduced sharpness and local contrast. Of course the sharpest condensor light source would be the point light source.

  8. #18
    dschneller's Avatar
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    Quote Originally Posted by naaldvoerder
    Hi forum,

    I am curious to know if there are enlargers, that can be equiped with a variocontrasthead/multigradehead and still use condensors. Or is diffused light in these heads a conditio sine qua non?

    Thanks Jaap Jan

    Hi,

    I have a Beselar 23CII with a Dichro Head that has been added. This enlarger is normally a condensing enlarger. With the Dichro Head I have the option of using a diffuser (two pieces of white plastic) or the condensing lenses.

    Hope this helps,
    Dave
    "...slow down and start using photography to create an image, not just capture one." b.e.wilson

    "Speed kills, Del" Johnny Fever

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