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  1. #1

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    Historical Kodak Internegative Films.

    Two Queries.

    1. Does anyone know anything about "Kodak Commercial Internegative Film, 4325", (exposure time range, was the Density Difference method used to work out the correct colour balance?), or have a copy of Kodak publication, No. E-255T which I could look at or make a copy of. Thanks.

    2. This is going back a bit !
    Ektacolor Internegative film in sheet form was introduced by Kodak in 1961. It was processed in a special developer consisting of "Kodak Internegative Replenisher + Internegative Starting solution. This applied only to sheet film, the 35mm version used the ordinary C-22 developer for a time.
    Does anyone happen to know if this special developer was used from the introduction, (day 1), of the film in 1961, or, was the ordinary C-22 developer used, with a reduction in development time, for a year or so.
    The earliest reference I can find for this special developer is 1964. (Kodak Professional Catalogue for the U.K., 1964-65.) Jack Coote in his book, "Colour Prints", 2nd Edition, published in February 1963, mentions Ektacolor Internegative film and gives 5 minutes for the development time in the same solutions and sequence as the C-22 process but he gives no mention of the Interneg Replenisher or Starting solution.

    I am doing research into Kodak Internegative films for a section on the Web Site "Photomemorabilia". There is some information on Ektacolor Internegative film already on the site, plus other interneg films, to be viewed at :
    www.photomemorabilia.co.uk.

    I may have asked this question before on Apug, but I'll give it another try !
    Thanks. MT

  2. #2
    Bob Carnie's Avatar
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    I used Kodak interneg film .

    I remember The Density Difference Method and yes it was one way.
    Another Was a program Kodak offered for plotting interneg curves and correcting for cross curve.

    There was a third method of manual plotting which I did not use.

    The number one factor that is still prevelent today...The plotting methods only got you to a decent balance . the final balance was done visually.
    Using an Image that included a person sitting in front of a graduated grey from black to white background, holding a large Macbeth colour chart.
    the person and Macbeth were only for quick colour correct reference.

    What was important was to see on the background the transition of grey, usually you would see a cross curve when you were off. the trick was to visually
    get the complete grey background neutral.
    The calibration method above would get you close.

    This was two step ... one step to calibrate the film.. second step make a interneg of the control transparacey .. third step print it on colour paper to best balance... fourth step look at the background and evaluate the cross curve if there was one... fifth step apply slight correction to the enlarger colour head balance to eliminate any cross... sixth step make new interneg with the master control transparencey... seventh step print on colour paper to best balance and see if you have eliminated the cross.

    If not keep repeating until you got rid of it...... We never trusted the plotting methods completely.. as they only got you to a good starting point. from there it was our EYEs

    Contact Internegs were also much superior than projected internegs.
    Reducing Flare and masking out the image was critical for making good internegs.

    I do not miss those days, A good interneg technician in the 80's was worth their weight in gold and usually the most desired for employment, as the whole process
    was based on good internegs.

    Interneg to print , was much more prevalent to direct positive printing in those days and a very important .


    Doug ( Blindpig) who is a new member here on APUG worked on the same equipment that I did in the 80's using , commercial Interneg film for transparancies and as well reflective art.
    He may have a better description of the above as Don certainly was an Inter negative expert working out of Kansas City, I worked at BGM imaging in Toronto and we both worked on the Lisle Camera , which was a computer driven overhead photo comp camera making large format final film composites for all industrys.

  3. #3

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    Michael, here is the scan of the Kodak E-225T publication on 4325 film:

    KodakE225T.pdf

    I have a bunch of Kodak 100T 4x5" film that turned out absolutely great for contact internegatives from Velvia and Astia. No plotting, no densitometry, just a bit of M filtration, overexposure, shorter development and - as Bob said - your EYES as the real judge. Surprisingly good results.

  4. #4
    John Salim's Avatar
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    I too used a lot of '4325' back in the day ( up until 1999 ) and the previous type of interneg film before that.

    I found balancing this film using the new method a lot more time consuming than the older film using the tri-colour method.
    ......never got round to trying contact printed negs though - wish I had.

    Prints produced always looked as though they were originally shot on colour negative, and in my opinion better and natural 'looking' than Ciba's and a million times better than any R-types.

    John S

  5. #5

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    Many thanks for the info, Bob, and for the "A good interneg technician in the 80s was worth their weight in gold........".
    I wish you had told my lab director that in 1974 when I worked in London at a lab doing their internegs while the regular guy was on holiday. I might have got a pay rise !
    I agree, the best way to filter internegs is visually from the prints, which I used to do. I started using Ektacolor Interneg film in 1970. I could'nt afford to buy the special developer to process them in so I used the normal C-22 developer. Ektacolor Internegative film was'nt the easiest film to use but it gave very good results if you took the trouble to filter it correctly.

    darkroom rookie.
    Many thanks for the pdf of E225T. I can now write something on Commercial Internegative film for "Photomemorabilia" and finish the interneg section off.
    I want to write something on "Gevacolor" negative films when I've finished the internegs.
    Many thanks. MT

  6. #6

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    Michael, you're welcome. If it can be of any further help, here are two more Kodak documents. "E-24T", on 4114 film, and a document in German:

    E-24T (download and then open the pdf)

    Commercial Internegative,
    EKTACHROME Duplicating und
    VERICOLOR Print und Slide Filme


    On a side note, I'm looking to buy expired 8x10" colour negative film. If you might find some, please PM me. Thanks.



 

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