life of a colour slide film

Discussion in 'Film and Processing' started by vishwanath_chandrahas, Dec 26, 2008.

  1. Hi,
    I just owned a Nikon F100 and am new to film photography. I was wondering if anyone there can tell me how much longer a slide film can be left in the camera once loaded, without affecting the picture qualities.
    I began with Kodak Ektachrome 100VS, are there any suggestions regarding this? Which other films can I go for?
    that would be great if any one can suggest me book on film photography that gives me the fundamental knowledge.
    Thank you
    - vish
     
  2. I am not sure I load a roll shot it all and develop it within a day or 2. :)
     
  3. The answer can be anywhere between a couple days and a couple years. The answer depends on what kind of stuff you shoot and how critical you are. For raw stock keeping (before exposure), if you just want a decent image, you can leave the film in there for 2 years if it is fresh. If you are shooting critical scenes with gray sweep backgrounds and you want them to match each other, the critical factor will be latent image keeping (after exposure). In a very critical situation, 2 days can make a perceivable difference.
    In general, you will get the best results if the film is well within expiration and is processed within a week or two of exposure.
     
  4. Non substantive films like Kodachrome can be left slightly longer as they are basically mono films where the colours are added during processing.
    Most films you should process within a couple of months, but can if you store the camera in a cool dry place still be Ok for non critical work for up to a couple of years, Pro films need to be processed more promptly as they change more over time if not stored correctly.
     
  5. Just don't worry about it, unless you have left the film in the camera for years - even then it wold be worthwhile to develop it - just to see what happened to it. YOu can use ANY 35mm film in your camera - but if I were you, I would stick with one film first, so you can see what you are doing wrong.
    Slid film is probably not the best film for a beginner because it is unforgiving. I would get a print film, like Kodak Gold 100 or 200 and use that to get prints made.
     
  6. Slide film is great for a beginner it shows problems faster that can be corrected quickly. Learning curve is accelerated.
    Larry
     
  7. "Non substantive films like Kodachrome can be left slightly longer as they are basically mono films where the colours are added during processing."
    I think I can shed some light on this. First, lets deal with the myth that Kodachrome is basicly a B&W film. I've heard it many times, especially from colleagues when I was the engineer in chage of Kodachrome formulation. It is an enduring myth, but it is not true. Check out slides 4-7 in this presentation: http://homepage.mac.com/randrews4/Kodachrome/KodachromeC.htm
    Kodachrome has the multiple layers that are typical of color films. It only lacks couplers (one part of a dye molecule). In both substantive and non-substantive films, chemicals need to be added to form dyes.
    Now lets discus keeping. If the dye forming reactions were the primary factors in keeping, this claim would be true. The primary factors in raw stock keeping are changes in the sensitivity of the silver halide crystals. The primary factors in latent image keeping are changes in the developability of the exposed crystals. The dye formation reactions are fairly stable. Non-substantive films like Kodachrome have no special advantage. Since Kodachrome is a much older formula it is a little less stable than some of the modern coupler incorporated films (i. e. Ektachrome). Modern formulas benefit from new technology and a better understanding of keeping.
     
  8. Hi All,
    Thank you many times for your valuable suggestions. I was thinking of storing slide film in the camera for 2-3 month but having read all your responses I am more confident to judge myself on storage life of films.
    Hi Nicholas, your suggestion to refrigerate the camera sounds paradox, thanks though. I would neve known this otherwise.
    Hi Larry, as you indicated slide film helps us learn faster. But what about the cost of E6 processing compared to negative film processing? I have no idea about it.
    Hi Ron, I take pictures of landscape and nature (this is for your information as it was not clear in my previous question). Nice to here from an expert like you. Your presentation is very informative. Is that ok to print it out and read and would you like to attach a down loadable file to my email ( vishwakc@gmail.com ) .
    Hi Juergen, can you please rephrase your statement "Slide film is unforgiving" I think there is a lot to learn from you.
    Regards
    -vish
     
  9. First, lets deal with the myth that Kodachrome is basicly a B&W film
    Its no myth:
    http://photo-utopia.blogspot.com/2008/12/how-it-works-kodachrome.html
    Kodachrome has the multiple layers that are typical of color films. It only lacks couplers (one part of a dye molecule). In both substantive and non-substantive films, chemicals need to be added to form dyes
    Wrong Kodachrome has no colour layers like substantive films, these are added through developers with couplers.
    What it has is a blue sensitive b&W layer a yellow filter a green/blue sensitive mono layer (Yellow filter takes out blue spectrum) and an othochromatic (extended red) B&W layer there are no colour layers in Kodachrome thats why it is non substantive.
    "both substantive and non-substantive films, chemicals need to be added to form dyes"
    True but with E-6 the colours are in the emulsion at exposure, with K14 they are added during the CMY developer/coupler process.
     
  10. As I said before, the myth is wide-spread. There are lots of references to Kodachrome being a monochrome film before processing. I respectfully disagree. Kodachrome was the first integral tripack color film. Monochrome films have one or two emulsion layers. Kodachrome has 6 emulsion layers just like other color films. (There is a fast and a slow layer for each color record.) The emulsions are spectrally sensitized to red, green, or blue, just like other color films. B&W films are generally pan sensitized. Some of the emulsion components used in Kodachrome have also been used in Ektachrome products. None of them have been used in B&W films.
    Polaroid and the old Kodak Instant film had all of the chemicals necessary to for a full color image. Compared to these self processing films, all other color films are lacking some of the chemistry necessary to form dyes. I wouldn't call them B&W films.
     
  11. Ron I don't want to cast doubt on your knowledge, but as you say you are an expert I'd like some clarification:
    "Kodachrome has 6 emulsion layers just like other color films"
    All my literature says four layers, top layer is a blue sensitive only B&W emulsion like those produced in the 1900's followed by yellow filter. Next layer is an orthochromatic emulsion (blue/green blue filtered by yellow layer) bottom layer is a blue sensitivity emulsion with a panchromatic dye to give blue/red (the blue being filtered by the yellow filter to record red)
    I have never heard of a 6 layer Kodachrome all my books say RGB mono integral tripack negative converted to CMY positive during fogging and development,
    Do you have a list of the layers?
    I don't doubt you have a lot of knowledge but I have several books that contradict your experience including a Kodak tech doc showing four layers, which is why you only have 4 developers Mono (PQ) yellow developer,Cyan and magenta the yellow filter is removed during processing.
    Can you show me a schematic of the layers?
    Integral tripack films can be mono, as long as each mono layer is sensitive to one component of RGB.
    Here is a colour picture taken on APX100 with non integral tri pack
    [​IMG]
     
  12. K-64 has 6 emulsion layers with 11 layers overal:
    Overcoat with matte, lubricant, and anti-static agent.
    UV filter
    Fast Yellow Emulsion
    Slow Yellow Emulsion
    Yellow filter layer with Carey Lea silver (that is yellow) and Lippmann emulsion that turns black in the first developer
    Interlayer
    Fast Magenta Emulsion
    Slow Magenta Emulsion
    Interlayer
    Fast Cyan Emulsion
    Slow Cyan Emulsion
    For the emulsion layers, I'm using the internal designations that refer to the color of the dye that is eventually formed in that layer. It is also a description of what the emulsion looks like before it is coated. The blue sensitive emsulsions are yellow in color, the green sensitive emulsions are magenta and the red sensitive emulsiosn are cyan. Of course the only way to see the color is to view it in white light which will fog the emulsion. People in the factory do see samples of the emulsions that are removed for testing.
    Many of the published diagrams of film structure are simplified just showing a red sensitive record rather than showing the individual layers. Older color films generally had at least two emulsions layers per record. Many modern films have 3 cyan and magenta layers. There was one color neg film that had a cyan record with 4 layers. It had exceptional grain when fresh, but the high silver levels made it very sensitive to background radiation.
     
  13. Substantive - term introduced by the Agfacolor Neu people...

    How long do the specific color sensitizers in the Kodachrome formulations keep?

    It is obvious that the sensitizers must absorb the complementary colors. But I doubt that a black and white-emulsion appears "colorless", i. e. yellowish-white only from the silver bromide/iodide crystals. Of course, in b & w sensitizers with a broader absorbance should be possible.
     
  14. Most of the spectral sensitizing dyes are very stable. One ot the two original green sensitizers oxidized slowly with time. That was the primary cause of the color shift from green to magenta as the film aged. This was one of those times when the short term high temperature keeping tests failed to predict the long term room temperature effects. Oxygen diffuses very slowy through gelatin. It wasn't until keeping tests were run at very high pressures that the long term effect could be studied in a reasonalbe amount of time. Once the cause was determined, the search was on for a more stable sensitizing dye. There were a couple of unsuccessful attempts. Finaly a more stable dye was found, but it left more stain in the film after processing. To compensate for the increased stain, we changed the red sensitizing dyes to a set that produced less stain. These red sensitizing dyes caused the latent image keeping of the red record to improve to the point where it was better that the green and blue records. This color balance shift was deemed unacceptable so we added an agent to the red record to make the latent image keeping worse so it was a better match to the other two records. This improved keeping package was introduced in K-64 in 1987. K-200 used the new set of sensitizing dyes from the outset. The volume of K-25 was too small to support a significant reformulation.
    As for the color of B&W emulsions, in many cases, the sensitizing dyes were not added until shortly before coating so the emulsions in storage were somewhere between white and slightly yellow, depending on the amount of iodide in the crystals. The T-grain emulsions in T-max films would have the sensitizing dyes added at the same time as chemical sensitization. I didn't have any experience with these emulsions.
     
  15. Ron Andrews... Your Kodachrome knowledge is AMAZING! I thank you for everything I have learned about my favorite film throughout the years you've posted on Photonet.
    Tom Burke
     
  16. You're welcome. It was my job for 5 years in the 1980's to understand this stuff. Fortunately I had several dozen engineers and scientists to consult with and several hundred operators who did the real work and taught me how things worked.
     
  17. R.I.P Kodachrome. I treasure my 55 years of Kodachrome movie film and slides. My friends' Ektachrome has faded to insignificance.
     
  18. Kodachrome is not dead yet. And I think we are all part of the lifesupport it is on. Keep pumping on the chest of Kodachrome and breath new live into the old gal. Nothing last forever but some things can be kept on Earth for a little longer.
     
  19. As I've said on this forum many times, my bet is that I will be able to shoot Kodachrome and get it processed in 2010 to celebrate the 75th anniversary of the product line. I created a website to promote this celebration: http://ronald.andrews.googlepages.com/kodachrome
     
  20. Ron
    I see the confusion when you state:
    "For the emulsion layers, I'm using the internal designations that refer to the color of the dye that is eventually formed in that layer"
    By eventually you mean after development, you are also counting both speed layers as single layers (which is fine but confusing)
    My Books state:
    Gelatin overcoat
    Blue sensitive mono layer
    Yellow filter of collodial silver
    Interlayer
    Green sensitive othochromatic emulsion
    Interlayer
    Red sensitive (Extended by injection of panchromatic dyes)
    Remjet anti halation backing
    Film base.
    Ron I'm not suggesting what you state is wrong, but rather deceptive it differs widely from all my information about Kodachrome (even that from Kodak)
    Kodak state that the film is essentially a series of mono emulsions with dyes to modify their spectral sensitivities. These are then exposed to light and each layer developed in a separate colour developer with the opposite colours coupler.
    What you say must be true if you worked on the emulsion for as long as you state, but can you explain why all other sources (apart form yourself) say it is a mono RGB sensitised emulsion sans couplers?
    Mark
     
  21. Mark,
    Some of this is the degree of complexity one wants to use in describing a film. All full-color films have at least three color records. (I'm not counting the 2-color Kodachrome as a full color film.) There are many sources that refer to color films having three "layers". These sources are simplifying a color record by describing it as a layer. If you define "layer" as part of the coating that has a consistenet composition, then all modern color films have more than 3 layers. The original Kodachrome films had 3 emulsion layers with big fat interlayers between them (necessary for controlling the dye bleach process). In the 1950's it was discovered that improved results could be obtained by using two emulsion layers for each color record. In the 1970's this idea was expanded to three layers for some of the color records. As I mentioned before, there was one color negative film that used 4 layers to make up the red record. (see Example 1a at column 14 in US patent 6,875,563). This particular film had a total for 14 layers.
    Perhaps I'm being too technical, but if there are two different kettles with two different green sensitive emulsions and these two kettles are delivered down two different pipes to the coating hopper and they are extruded through two different slots in the coating hopper and they don't mix together and you can see the difference when you look at a cross section of the film, then I would call them two layers rather than one.
    I'm not sure what book you are using, but it has some factual errors. The film base is between the remjet backing and the red sensitive record. The red emulsions use red spectral sensitizers that are different from panchromatic sensitizers. The reference to a "blue sensitive mono layer" is confusing. This could refer to a single layer blue record or a monochromatic blue record. All individual emulsions are monochromatic. It is when you put several different emulsions together in different layers that you for a color film.
     
  22. Ron
    Yes you're right the remjet is between I was remembering rather than looking at the books.
    The Books I'm using are:
    The Science of Photography H Baines Edited by E.S Bomback 1976
    page 266: 'The film (kodachrome) consists of four separate coatings on the base. The first consists of a non colour sensitised emulsion for the blue record. Under that is a yellow gelatin filter under which is an orthochromatic emulsion blue/green sensitive but because of the yellow filter blue light doesn't hit the layer so is a green record.
    Finally the bottom layer is a standard emulsion (blue sens) incorporating a special panchromatic dye with very little green sensitivity.
    Exposure thus records the RGB constituents in the three layers"

    (End quote)
    Also I have read in the book 'Film' by Michael Freeman.
    Page 108: Non Substantive film
    "As you use it (Kodachome) it is essentially a black and white film, with three colour-sensitized layers, the colours are added later"
    (end quote)
    Another Book Advanced Photography by M.J Langford
    page 180
    "As shown Fig 10.6 the film consists of an ordinary blue sensitive emulsion, the second being an orthochromatic, since both are blue sensitive a yellow filter is place between the two, thus making the second green only sensitive.
    The third is sensitive to red but not green.

    (End quote)
    It then goes on to give the mechanism by which the oxidized developer bonds the couplers to the individual layers.
    Lastly The theory of the photographic process fourth edition T.H James (C.E.K Mees)
    on page 337
    The p-phenelenediamine developer reacts with the exposed silver halides, the oxidised developer then reacts with the couplers (in the developer not film of course) to form dyes in the separate layers.
    It goes on:
    Among the acyclic methylene compounds that react with the oxidised p-phenylenediamines to form Yellow azomethine dye are beta-ketocarboxamides etc
    It then explains how the magenta pyrazolones and cyan phenols react to make indoanaline dyes.
    All very technical stuff :) but they seem to suggest that the colours are formed by the developer (or rather the oxidised dev) to generate dyes within each RGB sensitive layer, in other words those dyes are not within the emulsion at time of exposure but are made by chemical reactions between the developer and couplers in the processing baths.

    Thank you Ron for you patience.
    You see my problem in accepting your version, as it doesn't seem to agree with my literature on the subject.
    lastly:
    http://www.kodak.com/global/plugins/acrobat/en/service/Zmanuals/z50_03.pdf
    Where they state:
    Simultaneously, the resulting oxidized color developer
    combines with the cyan coupler to form a positive cyan dye
    image. This image is deposited only in the red-sensitive
    emulsion layer.
    That last quote seems to suggest that the dye is indeed formed in the red layer which if it is a panchromatic mono emulsion as seems to be suggested by all the books I've read would make sense
    Thanks
    Mark
     
  23. Mark,
    I don't know whether anyone else is paying attention, but I'm willing to continue the discussion. I understand the confusion. There are many sources that don't all agree.
    I'm not familiar with "The Science of Photography H Baines". I take issues with the quotes. The reference to "a special panchromatic dye with very little green sensitivity" is an oxymoron. Panchromatic sensitization must have green as well as red sensitization. In practice, there is no single spectral sensitizing dye that can be considered panchromatic. All panchromatic films have more than one dye to cover the spectrum. To refer to "four separate coatings on the base" and "Exposure thus records the RGB constituents in the three layers" is, IMHO, overly simplistic. I understand the confusion. I've used these simplified explanations in some situations, but I get a bit more technical on photo.net. It is technically correct to refer to three color records, but then you have to explain what you mean by a color record. It is easier to refer to three coler layers even if it isn't quite correct.
    The one source I'm very familiar with is the 4th edition of "The Theory of the Photographic Process". This was considered the "bible" in the Kodak Research Labs. I wouldn't dispute anything in that volume. The dyes in all conventional color films are formed when the oxidized color developer joins with the coupler to form a dye. This is true for K-14, E-6, and C-41 films (as well as ECN-2 and ECP-2 and several other processes).
    I'm disappointed (but not surprised) that the K-14 Z-Manual refers to only three color layers. This is not the only time that I have disagreed with Kodak publications. They like to keep things simple. I have used that same diagram that is included in page 3-4 of this reference. I also includes photomicrographs of crossections that clearly show two cyan and two magenta layers. (If you know where to look, you can also see two yellow layers.) Check slides 10-19 in this reference: http://homepage.mac.com/randrews4/Kodachrome/KodachromeC.htm
    It is true that if you process a roll of Kodachrome film in an E-6 process, you get blank film--just as you would with B&W film through E-6. But, you can't process a B&W film through K-14 and get an image either. To call Kodachrome a B&W film where the color is added in processing is overly simplistic. Perhaps the tongue in cheek comments from my colleagues have made me too sensitive to the issue. To me a color film is a film that records a color image and can, after development, reproduce a color image. Kodachrome fits that definition of a color film.
     
  24. Correction: If you process a B&W film in K-14, you might get a dye image, but it will be monochrome. The conclusion is not changed. A color film is a film that records a color image and can, after development, reproduce a color image. Kodachrome fits that definition of a color film.
     
  25. Hi, Ron...
    Are you saying that dye is not added to the film from the K14 processing solution? If not, was dye ever added to the film when Kodachrome was processed (K12 and earlier)?
    Tom Burke
     
  26. "If you process a B&W film in K-14, you might get a dye image, but it will be monochrome"

    Wouldn't the first developer bath give a mono image? I mean it is a fairly standard PQ type developer.
    Also if you put Kodachrome through a mono developer as long as you remove the remjet backing in an alkaline pre wash it is possible to get a mono negative, this is done when people find K11 films or 120 Kodachrome.
    The Baines book is a good one Dr Baines was deputy head of Kodak research in the UK I find it hard to think he would be in error, most of his data comes from Ken Mees as the two worked together.

    I checked out your slide show and yes it's a nice celebration of Kodachrome. Slides 2-4 do indeed show a yellow layer, but I feel this doesn't make it a colour film as that layer is not sensitive, but just a filter for the blue part of the spectrum akin to putting a filter over the lens if making Tri-chromes.
    Lets make an hypothesis:
    Say Kodachrome is a mono film sans colour couplers. Now take one layer say the green magenta. The layer is made up of a othochromatic (that means monochrome film right?) film that is a normal blue mono film (like films prior to 1890's) incorporating merocyanite to extend its sensitivity towards green.
    When exposed the latent image records only the green wavelength because of the yellow filter. When processed through the first bath (PQ) it is a mono neg image, it is then fogged and reversed then processed in a p-phenelenediamine developer with magenta couplers with make magenta methylene dyes when the couplers combine with the oxidised developer (as discovered by Fischer)
    So you see my point? I know it may irk you but I think Kodachrome may indeed be a mono emulsion where colour is added during processing...
    Mark
     
  27. just as an aside:
    I take issues with the quotes. The reference to "a special panchromatic dye with very little green sensitivity" is an oxymoron. Panchromatic sensitization must have green as well as red sensitization. In practice, there is no single spectral sensitizing dye that can be considered panchromatic.

    To be fair to Dr Baines he goes to great lengths to state that the red emulsion is BGR sensitive with a trough in the centre green region, therefore it is 'panchromatic' but with a reduced sensitivity in the green. The blue is blocked by the yellow filter above the trough in the green between 500-600 mยต and extended red make it a mainly red recording (with some green as no dye is perfect) layer. That could be why the dye in the red layer is a special pan dye, surely it must be possible to incorporate dyes in a mono emulsion with reduced green sensitivity?
    Possibly Baines should have said the Red record emulsion is a reduced green sensitive emulsion with extended red using dye technology from mono panchromatic emulsions to extend the red sensitivity in that layer
    Mark
     
  28. Any silver halide film will form a monochrome image in the frist developer of the K-14 process. Since all of the silver is removed in the bleach and fix, only a dye image will survive. Since some of the silver left undeveloperd by the first developer will likely be developed by at least one of the three color developers, there will be some sort of monochrome positive dye image.
    As for the description of Kodachrome as a monochrome film, we remain in disagreement on that score. Any color film could be described as a combination of three monochrome films. The lack of couplers does not turn an integral color tripack into a monochrome film. Similarly the presence of cyan, magenta, and yellow couplers in chromogenic B&W films does not turn them into color films.
     
  29. Thomas,
    The dye in all color films is added in the developer. In substantive films (E-6, C-41) the coupler (one part of the dye) is in the film and the developer (the other part of the dye) is provided by the color developer solution. In non-substantive films (all Kodachrome processes), both the coupler and the developer come from the developer solution. There are no color films (except Polaroid and similar types) where the dye is in the film at the time of exposure.
     
  30. Similarly the presence of cyan, magenta, and yellow couplers in chromogenic B&W films does not turn them into color films
    Ok but Ilford state their are no colour couplers in their XP2 that the dyes are purely formed in development, so I guess we'll have to agree to disagree on that one:
     
  31. Mark,
    First, some specifics:
    Quoting from the Ilford fact sheet (http://www.ilfordphoto.com/Webfiles/20061301945161573.pdf):
    "XP2 SUPER is a chromogenic film. This means that
    the dyes which make up the image are formed
    during development rather than being present in
    the film or added later."
    The word coupler does not appear in this document. This film is like all K-14, E-6, and C-41 films in that dye is formed during development.
    Now a general question:
    I have stated my definition of a color film: "To me a color film is a film that records a color image and can, after development, reproduce a color image." What is your definition of a color film?
     
  32. Ron
    I have read that XP2 PDF and I guess when they say there are no dyes in the film that there are no RGB layers just a single panchromatic record, I disagree that there are CMY couplers in the emulsion as they would normally be in the RGB layers- this film has no such layer structure.
    I am not a big XP2 user but I think from memory that the dyes that form are fairly neutral possibly of the blue family of analines possibly napthols in coupler form but certainly there are no CMY colour couplers in the emulsion do you have any information to the contrary?
    What constitutes a colour film? that is a big question. I guess I disagree that none of the constituents of kodachrome have ever been used in B&W many of the dyes indeed are used to modify the spectral responses of monochromatic films, in fact all that I have read backs up that it is a mixture of mono films that record colour in their layers rather like the colour from B&W I posted in the thread which uses filters to alter the response of the B&W film.
    For me I think a colour film has to have a colour sensitive layer with an incorporated coupler, sure that is a rigid and slightly inaccurate definition because I am fully aware of the nature of dye formation within the developer as oxidisation takes place.
    It is a subtle argument, no easy answers to the questions posed. I think that's why it resonates with you personally as colleagues within your organisation had differing opinions which is often the case with scientific questions.
    Just reading the many books I have on the theory of the photographic process throw up many such arguments, and I guess that's why I have questioned you in this thread I want to learn and if someone sings a different tune I will listen even if it doesn't mesh with all my current information.
    Mark
     
  33. If, by your definition, a color film must have incorporated couplers, then this clearly excludes Kodachrome. It also excludes the additive color systems such as Lumiere color, Dufay color, and Polachrome. It would exclude the Kodacolor lenticular movie that required color filters in front of the lens and the projector. It would exclude the thick Lippmann emulsions that record color by recording an interference pattern. You may want to expand your definition to include dye releasers if you want to include Polaroid and the Kodak and Fuji instant films. You are consistent with your definition--I just disagree.
    A minor point: you are correct the some of the spectral sensitizing dyes in Kodachrome are used in B&W films. What I wrote before was that none of the emulsions (the silver halide crystals) in Kodachrome have been used in B&W films.
     
  34. "It also excludes the additive color systems such as Lumiere color, Dufay color, and Polachrome"

    I thought about those, but they are additive systems and have the final colours within the emulsion before exposure, I actually added a paragraph mentioning those and the Clark-Maxwell experimental colour systems used by Prokudin-Gorskii but feel they can be colour films as the colours are in/or superimposed on the emulsions before exposure. I particularly like the Autochrome system with its tri colour starch grains and graphite but feel that these are of historical interest because of the many problems in obtaining consistent highlight densities have confined them to history.
    As for none of the emulsions of Kodachome being used in B&W according to my sources the blue layer (which they call the conventional sensitivity layer) is the same sensitivity wise as most emulsions pre 1890's after which chemists started using merocyanine to extend into the green region after the discovery of spectral sensitisation of silver halides by H.W Vogel
    So my argument is rather that Kodachrome uses some technology from B&W rather than the other way round.
    Thank you for your time and answering my questions, I am not an emulsion expert just a photographer but I have enjoyed our discourse, and please excuse me for asking so many questions.
    Regards
    Mark
     
  35. Mark,
    I wouldn't participate if I didn't enjoy it.
    As for some details, the blue sensitive emulsions in Kodachrome use technology from the 1950's. There is a spectral sensitizing dye although it is not obvious from the spectral sensitivity data. The emulsions are sensitized with sulfur (1925) and gold (sometime after that). They are washed by coagulating phthalated gel (1950's). The antifoggant dates from sometime in the 50's or 60's.
     
  36. The condensation/precipitation of the insoluble dye formed from the oxidized developer and the soluble coupler makes the Kodachrome-type color films so unique. But it is well known that B & W negatives can be printed into monochrome color prints by adding such a color coupler to a suitable developer, and removing the silver from the print after the development by a bleach-fixing solution, leaving only the dye on the print.
     
  37. Ron you state that Kodachrome blue recording emulsion used tech from the 1950's and that may be true but remember the film was already 20+ years old at that point.
    Sulphur and gold are often used in B&W emulsions to make more reliable sensitivity specs (electron traps) as are antifoggant which are often included in in emulsion Agfa used benzimidazoles in the 1920's and restrainers are added to both emulsion and developers.
    So none of those things mandate a colour emulsion
     
  38. Perhaps I wasn't clear. I was pointing out that the emulsions are considerable different from the emulsions of the 1890's. The emulsions of K-64 today are far removed from the emulsions in the original Kodachrome.
    While I metioned before that several of the emulsions in Kodachrome are used in other color films, there is no such thing as a color emulsion. One emulsion can only respond to one range of wavelengths. One emulsion can produce one color record (although most modern films use 2 to 5 emulsions per color record). At least three color records are needed to produce a color image.
     
  39. "I was pointing out that the emulsions are considerable different from the emulsions of the 1890's. The emulsions of K-64 today are far removed from the emulsions in the original Kodachrome".


    Which was my point, is it possible that early incarnations of the emulsion were as described by text books?
    You then go on to several of the emulsions are used in other colour films, yet the big difference surely is all other colour films include colour couplers in the emulsions, kodachromes are in the developer- I think that sets it apart.
    Sure some of the other components are used in the Ektachrome range like the yellow filter and some of the sensitising dyes etc. But also some of those dyes are in mono films.
    I would agree that there isn't such a thing as a colour emulsion per se but the inclusion of CMY couplers sets them apart from mono films and Kodachrome.
     
  40. "a colour film has to have a colour sensitive layer with an incorporated coupler"
    Mark,
    You might want to revise your definition. As written, it includes chromogenic B&W films. They include cyan, magenta, and yellow couplers--in the same layer.
    I'll stand by mine: "To me a color film is a film that records a color image and can, after development, reproduce a color image." We already have accepted definitions for substantive and non-substantive color films.
     
  41. You might want to revise your definition. As written, it includes chromogenic B&W films. They include cyan, magenta, and yellow couplers--in the same layer.
    No Ron, not according to ilford. They say they have one record - a panchromatic one and a single "nuetral dye' forming coupler. They do not include three layer RGB with complimentary CMY coupler.
    I don't know about the Kodak CN film but if the couplers are in one layer which is a mono panchromatic record then it can't be a colour film by anyones definition
     
  42. Mark,
    So we agree that a color films must have at least three color records?
    In "
    Technological Applications of Dispersions

    By Robert B. McKay" The author describes Ilford XP2 as using a "blend of different coupler dispersions". I know that the Kodak chromogenic B&W products use a blend of cyan, magenta, and yellow couplers.
     
  43. So we agree that a color films must have at least three color records?
    yes but as well as colour records RGB layers they have the complimentary CMY couplers for my definition I can make RGB separations from T-max (or any other mono film) and give you colour results but that doesn't make them colour films, the RGB layers must not only be integral but must have the couplers there before exposure.
    As for your link:
    XP2 has a single panchromatic record (no separate RGB) and a series of couplers that give an effective neutral dye formation XP1 just used blue( a little magenta too) which caused problems in printing on their multigrade paper.
    In your link it clearly states that a neutral dye image is formed (as I've stated Ilford techs have told me), actually says nothing about CMY couplers but I'd imagine as it is a Pan record the couplers would give a proportional dye formation to the Pan spectral response this in my definition would not make XP2 a colour film as it has no colour RGB layers (eveen if it has couplers.
    My definition is a colour film has separate RGB sensitive layers incorporating CMY couplers neither XP2 oir kodachrome have those.
     
  44. What about Polaroid?
     
  45. Ron
    I know even less about Polaroid, I'm no emulsion expert but I'd imagine Polaroid is a donor receiver type tech the actual negative part was discarded, but I'd imagine that the tech was similar to that of a colour negative with RGB layers but instead of going through a developer each layer had its own complementary developer ie Blue sensitive record would have yellow dye developer (and coupler)
    Other types of instant film (without donor peel sheet) had some sort of opaque layer above the image receiver to protect the developer from light which I believed broke down over time possibly with the p.h of the developer?
    But I don't know as I have never studied that process.
    But as I said I have no idea how it worked, the above is how I would imagine it worked and I have shot less than a dozen Pola images as it wasn't my bag.
    But I'm sure it had RGB layers and all the 'ingredients' to make it a self contained colour film.
     
  46. Polaroid uses dye-developers incorporated in (or was it adjacent to) the emulsion layers. The alkaline processing fluid activates the developer. Development renders the molecule immobile. Where there is no development, the dye-developer migrated to the receivor layer. Kodak and Fuji used dye releasers along with reversal emulsions that developed when not exposed. Oxidized developer reacted with dye releasers to release dye. I raised the issues because they don't conform to your definition because they don't have couplers.
     
  47. "Polaroid uses dye-developers incorporated in (or was it adjacent to) the emulsion layers"

    They according to my sources have a 'linked' dye, to me that means the colours are in the film during exposure.

    "I raised the issues because they don't conform to your definition because they don't have couplers".

    Yes they do, the developer has a complimentary linked colour dye, that would make them conform to my definition.
    Whereas Kodachrome has no such dye in the film during exposure which makes it a mono film until it goes through developer/coupler bath.
    To me a colour film Has:
    Separate RGB layers, a incorporated coupler or dye that is in the film at the point of manufacture. If that colour coupler or dye is added to the body of the film by a developer some weeks/months/years that is not incorporated within the film then it would not be a true colour film.
    Kodachrome is according to all my sources "effectively' a mono film at the point of exposure, you are the first person I've ever seen challenge that, and that includes people like Baines, James, Mees etc all people from an organisation you worked for.
    See why I need better proof before I change my mind? Backing up assertions with at least three respected sources is how I obtain information, I need the same from you before your argument can hold sway.
    Mark
     
  48. I'm being plarticular over words because couplers are different from dyes. The dye-developers in Polaroid and the dye releasers in Kodak and Fuji products qualify as dyes since they are colored. Couplers are (except for masking couplers) colorless. If you modify your definition to included both couplers and dyes, then it is consistent.
    I still contend that the essence of a color film is the ability to record and reproduce color and not related to whether some or all of the dye molecules are present in the coated stucture at the time of exposure. We will continue to disagree on that point.
     
  49. In that case i give you Fuji Neopan 400 the colour film:
    [​IMG]
    colours added during processing
     
  50. What was the process? Oil painting? Photoshop? Three color separations? Judging by the registration problems, I'm guessing this is from color separations. Since we agreed that to record a color image takes three color records neopan doesn't qualify.
     
  51. It is three colour records from separations one blue filter, one green one red, in three separate frame a la James Clark Maxwell but it fits your definition ;-)
    "I still contend that the essence of a color film is the ability to record and reproduce color and not related to whether some or all of the dye molecules are present in the coated stucture at the time of exposure"
    By the way this is tongue in cheek humour.
    Over and out
     
  52. The singular "film" was intended to rule out three color separations ala Maxwell, Technicolor, and the early work of Mannes and Godowski.
    Next time we'll have to start our own thread.
     
  53. Yep thread hijack isn't cool, I guess we're the only ones here who are interested in what is essentially an angels and pinheads type argument.
    regards
    Mark
     
  54. Ron and Mark...
    Hyjack away! I enjoyed the discussion, for sure. Shows that I can still learn something at my age?
    Tom Burke
     

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