RA4: elusive pure white

Discussion in 'Color: Film, Paper, and Chemistry' started by David Lyga, Jun 22, 2011.

  1. David Lyga

    David Lyga Subscriber

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    Am I the only person noticing this? If so, I’ll back off and let this post die a natural death. But…take a really close look at your borders. (I warn you that I am being a bit absolute here.)

    Since 1978 I have been processing ‘C’ prints, first with EP2, then, as now, with RA4. Back then I lived in New York City and regularly bought really fresh Ektacolor paper from Olden Camera (as there was great turnover there). From then to now, regardless of process or method, I have been mildly annoyed with something most might not even be noticing: the purity of the whites.

    When prints are fully washed after the process and left to dry, the tiny problem emerges without fail. Take a Kleenex or some white bathroom tissue or a piece of bright white copy paper and compare, closely, with the unexposed border of the dry color print. There will be a very small, but definite, level of density in the print’s white area no matter how fresh the paper. Optical brighteners do not mitigate this reality.

    Certainly, when looking at the print alone, without this relative comparison test, the print looks great because, mentally, we subconsciously make the small adaptation towards visual optimization. (We ‘know’ in advance what the print ‘should’ look like from our reservoir of common knowledge.) But what really got me noticing this and refusing to back down from this minor flaw was the fact that the dyes on digital prints do not ever touch the ‘virgin’ whites when they are not supposed to, and leave them truly pristine. In the RA4 process everything gets developed, exposed or not, and there always seems to be a tiny level of density present (which slowly increases as the paper ages). Obviously, changing filtration will not affect this tiny base density that is there solely because of the chemical process and without the aid of light, so attempts at filtration change do ‘improve’ the overall situation but the overall base is still there. Again, this becomes a factor only with the comparison with the pure digital colors. I hate to admit this superiority that digital intrinsically has over ‘C’ prints, but it is true. Analogously, this is like comparing the playing of a pristine 33 RPM record and then playing a CD of the same recording: suddenly, the almost nonexistent surface noise of the LP becomes apparent and we no longer can get away with letting out minds filter out this almost silent ‘noise’. (However, LPs may have other acoustical factors, some will say, that obviate this CD advantage.)

    The identical density problem is present also in the BW process. But there we have the luxury of passing the print briefly through a dilute Farmers reducer to bring back the pristine whites so that they shine. Also, in the BW process there are situations whereby a cream base ADDS to the aesthetics of the picture, and visually enhances the monochrome image. Unless for abstract reasons, this is decidedly not the convenient case with colors, as they demand purity to be most effective.

    Am I missing something here? Maybe this ‘complaint’ is not noticed or, instead, is considered too immaterial to be rightly discussed. But I do notice this and this factor keeps me from fully embracing the color process. Perhaps my being too much of a purist stands in the way of practicality and largely misses the point (I welcome criticism), but the factor is real to me and becomes a bit like looking at a color image though a skylight filter: it is that slight downgrading of the hues that I am talking about. – David Lyga.
     
  2. Athiril

    Athiril Subscriber

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    LP vs CD, much is also done in the recording and mastering process, modern mixing much more clean and clinical. Some CDs are not, you can hear noise (many recordings are still made with Valve desks, still can get noise with transistor desks too), fingers brushing against keys... etc.

    I've seen it from lab prints from digital (laserjet to RA-4), print came back grey and dull.. though a case of no colour management at all.

    "cream base" - many online hipsters colour cast their black and white levels in their images now so it's trendy.


    As for remedies.. sunlight/UV will reduce the dyes, though it may start affect the denser stuff first? Sodium Hypochlorite rips everything off a film including dyes.. I'd suggest a weak diluted solution of laundry bleach.. but that'd start eating away at the top layers..

    It sounds like you want some kind of reducing bleach. Metabisulphite + a small amount of sulphuric acid might be worth an experiment?
     
  3. timparkin

    timparkin Member

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    Out of interest, how do you choose between a paper with OBA's or without. If without then how do you live with the 'less than white' base?

    Tim
     
  4. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    I remember the old EP2 had a creamy base. The old Oriental color paper was gorgeous had a white base. Don't know of any RA4 papers have whiter base. Maybe Fuji makes color paper that has a white base. I remember the old EP2 print processor was a 12 minute wait. Today's RA4 is only 5 minutes. So much faster.
     
  5. L Gebhardt

    L Gebhardt Subscriber

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    Fuji Crystal Archive is whiter than Kodak Endura. I have never had an issue with the Fuji, except that sometimes it's too white. Of course I frequently feel the Endura is too yellow, so no paper is perfect for all images. But the density of either in the whites doesn't generally bother me, whereas the uninked sections on an inkjet do.
     
  6. Photo Engineer

    Photo Engineer Subscriber

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    Kodak Endura paper uses a TiO2 (Titanox) impregnated layer for whiteness. In that layer are many chemical preservatives and tints to make the Titanox as white as possible. The paper contains a UV absorber to reduce dye fade. The paper also contains an optical brightener which is present in the color developer made by Kodak (IDK about others).

    The preservatives tend to make the paper yellowish and the brighteners tend to remove that color and whiten the print.

    However, fog can cause stain in prints. Any print processed in a substandard manner or with a substandard process will have increased stain which is increased by the age of the stock you use.

    In the final analysis, all color papers will have a mild Dmin that has a density of about 0.15. The stain should be neutral if things work right! A stain of 0.2 or higher indicates a problem.

    PE
     
  7. David Lyga

    David Lyga Subscriber

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    Sorry Tim, I do not understand what you mean by OBAs.

    I live with what I must live with. The theoretical perfection is not there with base density. I have tried highly dilute laundry bleach but there never seems to be a dilution where I can get what I want. Either the bleach removes all or imparts a reddish hue throughout. The metabisulfite and sulferic acid sounds like it just might be the 'color' Farmers reducer. If so, Athiril just might be the next sage. How do I get sulferic acid:hardware store, grocery store, or must I formally apply to the photo chemical folks? - David Lyga
     
  8. Photo Engineer

    Photo Engineer Subscriber

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    Do you use a stop bath after the color developer? That will help.

    PE
     
  9. David Lyga

    David Lyga Subscriber

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    Yes, PE, always. About 1% FRESH acetic acidic acid solution, no sulfite though. - David Lyga
     
  10. Photo Engineer

    Photo Engineer Subscriber

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    Kodak or Fuji chemistry?

    PE
     
  11. David Lyga

    David Lyga Subscriber

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    PE: Kodak Dev/Repl RT(roller transport) bought from PDI Supply in Rochester, NY.
     
  12. Photo Engineer

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    Then, if your Dmin density is over 0.20 in any color, you have a serious process or keeping problem. If it is below 0.20 and neutral to warm toned, then this is normal. If it is greenish in any way, you have a fog problem or chemical contamination.

    PE
     
  13. David Lyga

    David Lyga Subscriber

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    Thank you PE; that is both what I wanted to hear (I am not guilty of any process defect) and NOT what I wanted to hear (that this is considered 'normal'). I will have to live with this. The prints look fine but I know that if they were done digitally I would obtain just that little difference which, in comparison, can actually be noticeable. There is a tiny bit of 'dry down', like on some BW prints. - David Lyga.
     
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  15. 2F/2F

    2F/2F Member

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    Sounds like digital would be preferable to you with most things.
     
  16. Rick A

    Rick A Subscriber

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    What about using Fotospeed CSP 100 as final wash or after final wash, isn't it supposed to brighten(and whiten)prints. I'm not familiar with color chems, but read about the stuff when I was considering color printing.
     
  17. Photo Engineer

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    I think that a point that must be made is that ALL reflection print materials have a minimum reflective density of about 0.1 in all three colors. This is just due to the laws of physics and chemistry. Baryta and Titanox have that characteristic. You will find this to be true with both digital and analog prints. There is nothing that can be done about it.

    Now, digital prints maintain that value because if there is no density, then the ink or pigment is not applied.

    With analog prints, all areas of the paper are treated with all of the chemicals and there is always some level of fog and stain. The fog is just normal random grains that develop and the stain is due to the process chemistry.

    So, there you have it.

    PE
     
  18. richard ide

    richard ide Subscriber

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    Someone should invent borderless prints. :munch:
     
  19. David Lyga

    David Lyga Subscriber

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    RIchard Ide: the borderless prints do not solve the inherent problem: the degradation is still incorporated into the whole layer of sensitivity. It merely removes the immediately obvious degradation. I wish there was a way to reduce, overall, the density layer like with Farmers reducer for BW. - David Lyga.
     
  20. richard ide

    richard ide Subscriber

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    David,
    I understand the the problem, but it is one with no apparent solution. At least with BW there is an option if base fog is present.
     
  21. hrst

    hrst Member

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    If you are talking about digital RA-4 prints and not inkjets, remember that they use the same or same kind of paper and same chemistry and thus suffer from exactly the same problem. You just usually get them with borders cut. If you are seeing a difference in white borders between a digital RA-4 print and analog RA-4 print, there is some kind of problem in your process... Or, if you use the old-style Supra Endura, it might have a bit higher Dmin than the papers used by digital printers. You can try the same papers they use, or try Fuji CA. I agree it's a little bit more white.

    Also, blix can cause yellowish staining in some problem cases. As you are using Kodak chemistry, this probably isn't the issue but check that it's fresh and correctly mixed.
     
  22. David Lyga

    David Lyga Subscriber

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    hrst: Absolutely correct: whether 'writing' digitally to RA4 paper or doing it the standard optical way there is STILL the process itself which imparts the 'tiny fog' I speak about.

    BUT...if the color print is made in a printer, the color that is not wanted ('tiny fog layer') simply does not get put onto the paper because the white part does not get compromised by any chemical process: it STAYS pure white. THAT is where digital, at least theoretically, provides potentially purer colors. - David Lyga
     
  23. Athiril

    Athiril Subscriber

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    Just watched an ad for nappi san, whitens fibres and removes stains. Should try it on paper. :tongue:
     
  24. hrst

    hrst Member

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    Yes, but color pureness if a completely different matter than Dmin.

    Our eyes have an automatic exposure control, thus any constant amount of density is automatically corrected for IF there is no comparison point in the view at the same time. This trick is constantly used by varying the background color where the prints are mounted; the same prints look totally different when mounted on black instead of white. Mounting a print with limited Dmin on a very slightly gray background makes the print look same than mounting a print with a better Dmin to a white background.

    Of course, there is a limit. If the Dmin is really bad, you will need special lighting and mounting place for the print which is not practical anymore. But as the Dmin in RA-4 process as well as Ilfochrome process (which "suffers" from exactly the same "problem") is quite near, or "near enough", to good white, the problem is obvious only when specially seeking for it by comparing to, for example, a copy paper filled with optical brighteners. Cutting the white borders "hides" the problem and so it becomes purely psychological, mattering only those who know it.

    But in the end, as the photographs are a medium of visual art, the end result should be what matters. On the other hand, any technology has bunch of invisible problems you just don't know about.

    Color pureness you are talking about, on the other hand, or how vivid and rich colors can be reproduced, is more dependent on the dye reflectance spectra.
     
  25. 2F/2F

    2F/2F Member

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    I think that if the OP does not like the way type C prints look, he should print inkjets. But I have personally never had a problem with the way type C prints look, however, and neither does any photo gallery I know of that displays color work. They do, however, often have problems with inkjets. Even the OP said he didn't notice the fog until he compared it to a napkin or something. (I am paraphrasing from memory here; sorry if I got it wrong.) In that case, the old cliche should be applied: If it ain't broke, don't fix it.

    Also, "digital print" and "inkjet print" are not synonymous, though they are often being used as such in this thread. (I would actually argue that there is no such thing as a "digital print," only a "print from digital," but I see no purpose in getting deep into that here.) Digital files may be printed a number of ways (inkjet, type C, type R, offset litho, screen print via printed-out transparency, alt process via inkjet negative, etc.), just as frames of film may be printed in various different ways (silver-gelatin, type C, type R, screen, offset litho, alt process, etc). The source of the image (film frame or digital file) is separate from printing processes, for the most part. I.e. You cannot tell whether the image was shot on film or digital simply by looking at what type of print it is on a gallery tag. I could label a print shot with my Nikon digital camera as a type R print if I had printed it via Lambda/Lightjet to Ilfochrome material. And I could label a print shot with my Nikon F an inkjet print if I scanned the film and made the print with an Epson.

    The use of the phrase "digital print" to mean "inkjet print" can lead to a lot of ignorance and/or misunderstanding if it is read by people who are beginners in the craft.
     
  26. hrst

    hrst Member

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    To me, term "digital print" defaults to RA-4 laser exposed print, which is clearly the most common type of digital print made commercially.