Colour Negative Film and Filters

Discussion in 'Color: Film, Paper, and Chemistry' started by Roger2000, Sep 1, 2011.

  1. Roger2000

    Roger2000 Member

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    Hello,

    In the recent discussion about Kodak Ektar vs the Portras, the focus very quickly changed from the difference between these two films into a discussion about using a filter on your camera when taking pictures using colour negative film. Of Ektar, Mr 2F/2F said this:

    Proper exposure of all the color layers is very important with this film. That means you will have the easiest time printing if you filter it:

    - any time it is cloudy
    - any time it is overcast
    - any time your subject is primarily in the shade or in window light
    - any time it is more than a few hours either side of noon.
    - any time you shoot under artificial light that is not daylight balanced (i.e. most artificial light in our day-to-day lives)

    Given what many people tend to shoot, this means that most people should filter this film a good deal of the time. The same is true of any color neg material, but especially important with this film due to the fact that it's contrast lowers it's latitude for imbalanced color.


    There then followed a discussion about when and with what to filter colour neg film.

    And it's all left me rather baffled.

    I've used colour negative film for the last three or four years now and never used a colour correction filter. In all that time, I have never thought that the colours in the final photograph were 'off', whether shot in daylight or with a flash.

    I have had many minilab prints made and recently started to make optical RA4 prints.

    This makes me think that one of these two conclusions may be valid. Which do you think is more likely:

    a. the need for filters (80, 81, 82 etc) has been overstated by people in the Ektar v new Portras thread; or

    b. some of my pictures would have turned out with far better colour (noticeable to the man on the street) if I had used the relevant filter in open shade or under a cloudy sky etc.

    Many thanks for any contributions!
     
  2. iranzi

    iranzi Member

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    I had exactly the same thought, that those statements warrant a separate thread. I just paste my question here:

    Just been rereading this thread. Very interesting. But somehow I can't believe shooting daylight negative film in overcast/cloudy/shadow conditions outdoors will cause any problems. Has anyone here done any testing or seen results of such tests that show necessity of in-camera filtering for colour negative film? It sounds very strange to me that any of the above conditions will cause loss of density in any of the layers so severe that filtering during printing won't be able to restore without introducing color shifts. I've never seen in-camera filtering for negative film recommended in any of the colour photography books either. So, i'd be very grateful if any of you can quote from any reference, books, articles, tests, etc that prove your point.
     
  3. Athiril

    Athiril Subscriber

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    As stated in the other thread.

    I could colour balance easily an unfiltered shot as well as one with a Tiffen 85 series filter. Identically. The filtered shot (being overcast as well as under a forest canopy type thing) had richer colour with the same balance and contrast.
     
  4. Michel Hardy-Vallée

    Michel Hardy-Vallée Membership Council Council

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    I shot Ektar 100 in my Rollei with the R5 filter with a subject in full open shade, and it turned out excellent. It's probably easier to correct colours thus than to fiddle with Y+M at the printing stage.
     
  5. DREW WILEY

    DREW WILEY Member

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    If you're getting the results you want, I guess that's all that matters. But I'm fairly amazed to see the
    actual images of people who wing it with color neg film, or who brag how they can correct anything in
    Photoshop, well, except this or that, so it must be the film's fault, and Kodak is really dumb. To me their
    wonderful images look very off and fall far short of the real potential of the film. We all probably do things deliberately creative with our favorite films; but a lot of these folks are defaulting through ignorance of technique. My darkroom prints from Ektar, and to a lesser extent, the older Portras, look
    very clean, vibrant, and rich by comparison. I've learned all this the hard way; and when one shoots 8X10, there's a real financial sting to an unbalanced exposure. When you don't filter and expose as needed, you've not only got a color balance problem, but are effectively altering the geometry of the three dye curves relative to one another. I don't know how much detail I want to get into, if folks are unfamiliar with the sensitometery of color films; but this is something which CANNOT be post-corrected. All three color layers are affected in a variety of ways, depending on the specific film, and some of this
    turn into what I call "mud".
     
  6. jglass

    jglass Subscriber

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    1. Let me ask again for recommendations on a consensus, authoritative book or web book on use of color filtration on color film. Someone suggested Horenstein. Any others? I need a basic primer, with reference to these weird filter numbers that you guys are tossing around.

    And it would be very nice to see comparisons of with and without filtration in some of these problem situations.

    I've also been winging it but have definitely been dissatisfied with results in some mixed lighting, mixed sun/shade situtations.

    2. what filtration would you experts use in a situation involving deep-ish shade (forest?) with bright sun shafting through and the subject in the sun?
     
  7. DREW WILEY

    DREW WILEY Member

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    First of all, in terms of specifics, we're talking about a fairly new set of Kodak films. So don't expect some book to be available. And in terms of "authoritative" or "consensus" on the web, well, good luck. The web is loaded with BS, and you have to do some sifting. If you want to understand the real nature of the problem you have to study basic sensitometery and learn how to interpret the published curves etc thoughtfully. Books on this subject are available. But just try taking my word for this, and experiment. Mixed lighting will always be a challenge because you are dealing with more than one set of
    circumstances in the same scene. You can compromise filter, or not filter at all, and just let the chips fall where they will. In a film like Ektar the deep shadows under an open blue skies will tend to go an
    uncorrectable blue, while the rest of the scene will fall into place. Ektar doesn't have the warming "mud"
    of overlapping film curves to the extent of traditional portrait neg films. Each new film entails its own
    learning curve to recognize its particular signature. But if the overall scene is in deep shade under
    blue sky, I'd recommend an 81C. A lower-contrast film like Portra 400 might be slightly more forgiving in
    mixed lighting. Color transparency films aren't wholly immune from analogous problems - the difference is,
    we can just slap them on a lightbox and immediately recognize the idiosyncrasies. Reading color negs takes a lot more experience and generally actual printing too. And after awhile, people tend to accept
    those idiosyncrasies as representing something real. Just thumb through some of the shots in something
    like Natl Geographic and see how many published images reflect the color bias of some film rather than
    anything real, especially in night shots. Lots of blue that was never there in the original. Call it creativity
    or call it cliche, it simply proves no film is perfect, and maybe shouldn't be.
     
  8. Athiril

    Athiril Subscriber

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    People go too far when they say the film cannot be colour balanced the same when you're simply shooting the shade let alone overcast situations. I've had no problem colour balancing Ektar unfiltered shot inside a forest.


    Conversely the Konica Centuria Super 100 (120) I shot unfiltered vs filtered in heavy overcast under a forest canopy, as I stated before, it colour balances identically filtered vs unfiltered, obviously different values for each balance. It has a richer look to the colour filtered though. This is the filtered shot, it may look too warm to some, but this was my chosen colour balance, saturation has been slightly increased by a small amount over what the scanner's response is to the film (which is typically lower saturation than RA-4 printing to begin with) as I play to the strengths of the image.
    [​IMG]
    Marysville Ranges? by athiril, on Flickr

    This is the only recentish comparison I have done. I'll try to dig out the neg sheet at some point to find the unfiltered shot which I didn't use again for comparison purposes.
     
  9. DREW WILEY

    DREW WILEY Member

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    The problem is with MIXED lighting. I've shot Ektar and Portra many times in deep shade in the redwoods
    or under our frequently overcast skies. Might do more of that tomorrow, though the sun is likely to come
    out in the afternoon and result in mixed light. Easy to filter for. The difference is, that if I don't, and just
    expect to correct the color balance with the colorhead afterwards, the exposure level of the different
    dye spikes will be out of syn, therefore unmatched in intended geometry, so certain things just can't be corrected that easily could be in the first place (unless you're breaking the rules on purpose). When
    in doubt, it's safer to overfilter for the blue cast a little than under filter it. I really hesitate to outright
    argue with people who haven't actually done such filter corrections, especially the "I can do anything in Photoshop" geek mentality who have no higher expectations than what they see on the web. Minor
    changes in photo habits can indeed result in significant cumulative improvements in print quality. This
    is one of those relevant factors.
     
  10. Roger Cole

    Roger Cole Member

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    I'd love to see some real comparison prints, not scans of prints or, even less useful, scans of negatives, done by a really experienced color printer like Drew, of unfiltered versus filtered shots. I've never filtered it either, and aside from something extreme like indoor incandescent or, worse, fluorescent, I've never felt it was uncorrectable in printing or really all that difficult to correct. Granted it's been over a decade since I was doing color printing, and I also point out that I make no claims that I could make them look identical or even "just as good" since I didn't do side by side comparisons. I just got results, without too much trouble, that were fine to me. I'm perfectly willing to consider that my standards might just not be what they could be.

    Comparison scans with no or at least the same post-scan corrections, to make them look as similar as possible to the originals in the eye of the person who did the original printing, would be interesting but maybe not as telling as viewing the actual prints. Unfortunately we don't have an easy way to directly view the comparison prints themselves across the Internet.
     
  11. DREW WILEY

    DREW WILEY Member

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    These new Kodak color neg films really are quite a bit different than they used to be. For one thing, the
    dye spikes are a lot steeper and more "spikey" than before, esp with Ektar. That means the potential for purer hues and actually less chromaticity error when optimized, but also less forgiving, at least until you go further down the chain of contrast, where the priority is on skintone reproduction (or at least, a visual stereotype of analagous warm neutrals). Unfortunately (or fortunately) I don't even have a digital camera for web use; and the web it a very blunt axe anyway. I do have some 'dud' CA prints laying around relative to my own comparison prints which I could take snips from, but not right away - getting ready for a trip.
     
  12. Athiril

    Athiril Subscriber

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    Again, I've had no problems with that. Mixed lighting is mixed lighting. The obvious needs to be pointed out. It is not supposed to be balanced at the same time on the neg, they are supposed to render with a differential. Which they do, regardless of your filtering. They are spectrally different. Ektar does not have the kind of problems you are talking about in the mild scenario of mixing 5600K with 6500K you are describing, it is no where near any extremes that can occur. Indeed minor changes in your photo habits can result in significant improvement, so I would take a look at your metering technique and your lab processing quality.

    Your attitude here is a very ad hominem approach. No that it makes any kind of difference to the validity of my ideas, I should point out the fact your ad hominem type attitude also is relying on several attitudes and pre-conceptions about other people which you have no idea about to begin with, making it that much more ridiculous. EG; I do have an enlarger, a Eurogon Dichroic, and I have my preferred method of shooting

    I do have an enlarger, it is a Eurogon Dichroic. I have my preferred method of shooting. I upload few of the images I take, and print even fewer. I certainly do not have a "I can do anything in Photoshop" approach. The image above and the unfiltered version will colour balance the same on an enlarger as I have not done anything that cannot be done on the enlarger I own with it.

    As an aside: Balancing on an enlarger optically is the last concern since the vast vast majority of RA-4 prints originate from scans, as very few people who make wet prints from colour film do it themselves with an enlarger (the majority concern is whatever the majority workflow is (the majority of sales of Ektar)). They get it done at a lab, from their scan, or from a minilab scan, etc. So more complex colour correction apart from a simple colour balance is perfectly applicable in the evaluation of the usage of Ektar (especially since it is a scanning film). Obviously a better quality neg is one that needs the least amount of work and only simple correction, with that in mind, it will optically enlarge well as a benefit as well.

    Everyone here will be shooting film, and very very few of them here will be getting film-to-paper wet-prints.




    Here is some Ektar from sunday, the only filtering is from the CPL, it is incident metered in the direct sun (adjusted for filter), and 1/3rd over that I think if I remember correctly from the time. It was a very high contrast scene, there is a lot more shadow detail on the neg than what is apparent in the image, as I chose to make it a bit more natural rather than having grey blacks. It is a straight colour balance, the same as what I can get with the dials on my Eurogon.

    It looks natural, as does the differential light temperatures. I certainly wouldn't try to colour balance a neutral scale in both of them at the same time. That would be highly unnatural, I prefer the image to look natural for the most part, so I certainly do not wan't the colder portion of my image looking any closer to white/grey/neutral.

    [​IMG]
    Waterfall by athiril, on Flickr



    Otherwise what you are talking about is simply not a mild mixture of lighting, but a drastic one, which of course, is a dramatic different in light temperature. Your eye has local chemical sensitivity of exhaustion to intensity (both luminous and chroma). The film does not. Because it would sound like you are mixing shade as high as 10,000K with sunlight as low as 4,000K, and then throwing in 20,000K skylight.
     
    Last edited by a moderator: Sep 2, 2011
  13. David Lyga

    David Lyga Subscriber

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    I regularly use a yellow filter for outdoors and NO filter under tungsten. More yellow is required when printing but I like the slight improvement with contrast with daylight exposures, especially in shade. (Indoor exposures already have the slight increase in contrast.) B&W or color, negative film likes Kelvin 3000 and hates Kelvin 10000 (except don't do this with reversal color!) - David Lyga
     
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  15. DREW WILEY

    DREW WILEY Member

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    You're somewhat missing my point, Athiril. It's not just about color balance. It's about relatively minor
    variations in the exposure difference between the different layers causing mismatched geometry in the
    curves, and therefore certain uncorretable nuances. Ektar is especially sensitive to this. It might not
    matter to some people, but does matter to me; and at times even a modest 81A correction will make the
    difference between a merely OK print and one in which the hues absolutely sing. Optimization is the name of my game. Yeah, I'm very nitpicky how my prints look. I don't expect other folks to play by my
    rules; but if they too want optimization of color neg response, this kind of filtering is a necessary element. Or at least, recognition of it is a valuable factor in deciding when to break the rules; for example, when you want the shadows to go blue and when you don't relative to the subject. Mixed
    lighting with filtraton gives you options that mixing lighting without does not. And in this respect, color
    neg films are a different animal than chromes. The problem is, photographers just got too accustomed
    to what they think neg prints inherently look like. When an improvement comes along from the traditional
    mud, they go "wow", but don't invest in the full potential of the new films.
     
  16. iranzi

    iranzi Member

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    Can you refrain from talking for some presumed "majority":"Balancing on an enlarger optically is the last concern since the vast vast majority of RA-4 prints originate from scans". WTF?

    "Balancing" in the enlarger is a major concern of this thread. And all the scanning "majority" should take their problems elsewhere.

    Also, this wiley is all over the place making no sense at all with his dye spikes and all the rest.
     
  17. DREW WILEY

    DREW WILEY Member

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    Makes no difference. The nature of the problem is analogous whether one is printing in the darkroom or by any other means. If you're off on the wrong foot when you take the shot in the first place, you are boxed in as far as potential corrections are concerned. But it's all there on the mfg tech sheets anyway. Why do you think they publish these things in a standardized fashion? But you have to learn the vocabulary, which in this instance is on a graph and logarithmic. They've already done a lot of the work for you and make it easy to compare one film to another, once you understand the basics. Being
    able to correctly interpret the dye spikes saved me about six more months of testing and several hundred dollars. For example, just compare the dye curves for Ektar from those of Portra 400 and
    ask what the practical significance is of the difference. This same kind of shorthand has been the
    standard way of objectively comparing film for decades. You still need to do personal testing to get
    the feel for the specific signature of a film; but ignoring the dyes curves is about like ignoring the
    ASA if you want to avoid wasted time and money, and disappointing shots.
     
  18. Roger Cole

    Roger Cole Member

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    So far I was agreeing with you completely. People "on here" are likely to be most interested in optically printing onto photo paper. I won't dispute this isn't true for the majority of people, but those aren't on here.

    At least I am primarily interested in optically printing with an enlarger onto RA4 photo paper. I care a bit less about scanning for web or my own ink jet output, and not one bit in the world for scanning by a lab or for the lab to output my scan on a lightjet, inkjet, holodeck or replicator. Whatever. I'm going to optically print mine.

    But then you we suddenly and abruptly part company of opinion:

    Drew is making perfect sense. His comments about the dye response peaks make perfect sense to anyone who knows the slightest bit about color film and sensitometry. That would be me, someone who knows "the slightest bit." I'm far from an expert, don't own a desnitometer, but his comments are completely lucid and make sense. I for one appreciate his input.
     
  19. Athiril

    Athiril Subscriber

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    No. The vast majority of RA-4 prints come from scans. As the vast majority of RA-4 prints come from minilabs. Most colour shooters don't process their own film let alone print. Those who print their own RA-4 directly from a film negative with an enlarger are the minority of colour film shooters.
     
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  20. Athiril

    Athiril Subscriber

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    Actually they are on here. APUG is one of the best and most popular resources for film shooters.

    APUG unfortunately seems to attract a lot of people that have attitude problems and issues with just about everything, and have very easily offended sensibilities with just about everything again.

    They make this place less friendly and scare off an unknown number of film shooters.



    The film is daylight balanced, you do not have to go far to correct for daylight, shade falls where shade falls at that colour balance, and that is both normal and correct.

    I've had identical colour filtered and unfiltered in situations close to daylight, including mixed light that has all originated from the sun.

    The film is 5600K balanced. 5600K is direct sun, direct sun throws shadows, and simply will be by definition your specific very mild example of "mixed lighting".

    As far as what the "mfg" has specified, they have published that Ektar has nearly 11 stops of a straight line response for red (cyan forming layer), green (magenta forming layer) and blue (yellow forming layer).

    If you have uncorrectable problems with that shooting in a 5600K situation that is changed by very minor filtration, then the problem is with you - either exposure, processing or psychological.
     
  21. Roger Cole

    Roger Cole Member

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    I don't have an attitude problem and I don't have any problem with people shooting negatives for hybrid work flow, which is what you are talking about whether you call it that or not. But APUG has made a big stink about not being about hybrid methods. FWIW I don't agree with that. I'd like to see it encompass shooting film for such purposes. But I don't make that decision and it's not within the stated subject matter of APUG.

    More importantly, I think, while I agree the majority these days are scanned one way or another, those aren't the people who primarily come here. This is a different audience.

    I'm not even against arguing that, "for scanning purposes filtration concerns are different because..." etc. What I'm taking issue with is the idea that optical printing via an enlarger is such a small group as to not be a consideration. That may be true for the manufacturer who needn't be too concerned with our small quirky little band of darkroom workers, but I don't believe it is generally applicable here.
     
  22. DREW WILEY

    DREW WILEY Member

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    You are plainly ignorant of the basic implications of color neg sensitometry, Athiril. If so, and you are
    happy with the results you are getting, that's fine with me. It does not change the objective facts which might be very useful to someone else. So you are perfectly welcome to ignore the following
    analogy. Let's visualize three great volcanoes in the Hawaiian Islands: Mauna Kea, Mauna Loa, joined at the base, and Haleakala off on Maui. From out at sea or in the air, as a panorama, these peaks
    not only have their individual altitudes, but a distinct individual shape respective to one another, based upon sea level. Now lets imagine you "sink" Haleakala or underexpose it just by 500 hundred
    feet in altitude. If you do this, you have not only changed the height of the island, but the entire profile and shape of Maui. It geometrically becomes something entirely different in relation to the
    other two peaks of the Big Island. Suddenly, the Kona coffee growing zone on Maui is not aligned in
    elevation the same zone on the Big Island, but with lava beds covered with thorn bushes. So when
    one underexposes the yellow dye layer of a film, it is not just the reproduction of pure blue which is
    affected, but of every other hue which need any yellow dye whatsoever. The colors get off, muddied
    to some extent; and even if this is slight, it fails to achieve the full potential of the film to reproduce
    the chroma in the scene.
     
  23. Tim Gray

    Tim Gray Member

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    I don't have a dog in this current fight, but I would like to point out that there are probably more people on APUG who scan than you realize. I shoot only film, dev and wet print my B&W, and scan both my B&W and color. I'm just not allowed to talk about that last bit. Doesn't mean I'm not doing it (just like a lot of other people here).

    Don't misinterpret scanning not being talked about on APUG as nobody on APUG scans their color.
     
  24. Athiril

    Athiril Subscriber

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    If this is happening to you in daylight as you insist it is you are underexposing your film or the processing of the film isn't good. You've already admitted the problem takes underexposure to cause, hence there in lies the clincher.

    What is funny about what you say is that Ektar is worse than Portra 400. Which again, is very funny, since the yellow dye forming layer (blue sensitive) has a far steeper gradient in spectral sensitivity in Portra 400, which means less change in blue spectral width when underexposing.

    Again, take a look at your exposure (and if necessary, the t-stop of your lens), processing.

    Because honestly, it's ridiculous what you have been saying, again daylight film can't cope with daylight situations without filtration (since daylight is your definition of mixed lighting daylight and the shade created by it), where you say an 80A makes big difference in the print between ok and fantastic. That has a filter factor of 0.485 stops, and a MIRED of 18. Your film is obviously not getting enough exposure.

    The vast majority of film shooters take their colour film to be processed at a lab or mini-lab. APUG is a highly popular site on the internet for film shooters and caters to a wide audience.
     
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  25. Athiril

    Athiril Subscriber

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    I will not recognise it as a hybrid workflow, for all of time the majority of colour film shot has not been processed by the person shooting, but by a lab or minilab that they pay to have it done.

    Sending it to a lab or minilab has always been the normal workflow for colour neg. Thus the normal workflow for the past several years has been to scan and do a laser wet print.

    These new films are designed for this workflow in mind. FWIW I wasn't pointing the finger at you when referring to some people's attitudes on here that chase away new users.
     
  26. brian steinberger

    brian steinberger Subscriber

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    I agree greatly that APUG should be more loose about discussing "Hybrid" work-flows. And yes there are probably alot of us scanning that are members of APUG but are too scared to share our knowledge on scanning because we're afraid we'll get scolded. I'm sure I could take my questions to DPUG, and I have, but the truth is that there just isn't as much help or folks on the site as there are here. So if the people are here, and the knowledge on the topic is here, then why can't we share it and talk about it?! After all, we're all still shooting film!