Latitude of colour negative film

Discussion in 'Color: Film, Paper, and Chemistry' started by Medusa83, Dec 3, 2009.

  1. Medusa83

    Medusa83 Member

    Messages:
    72
    Joined:
    Jul 6, 2006
    Location:
    B.C., Canada
    Shooter:
    4x5 Format
    Hey guys,
    I haven't been able to find any solid info on the number of stops one can expect out of colour negative film. I read somewhere that it was between 7-9 stops and elsewhere that it was -2 to +3. I am specifically interested in portra 400nc and 160nc. Can anyone help thanks!!!!
     
  2. AlexG

    AlexG Member

    Messages:
    97
    Joined:
    Mar 24, 2009
    Location:
    Sacramento,
    Shooter:
    Medium Format
    Direct from the KODAK Darkroom Dataguide 1990 (I don't know how this info holds up today, though.)

    Color neg Film Acceptable Exposure:
    3 stops over
    2 stops over
    1 stop over
    Regular exposure
    1 stop under
    2 stops under


    Transparency Acceptable Exposure:
    2 stops over (very overexposed - possibly unusable image)
    1 stop over (whites are blown out)
    Normal Exposure
    1 stop under (contrasty image)
    2 stops under (very contrasty and dark - possibly unusable image)
     
  3. DanielStone

    DanielStone Member

    Messages:
    3,107
    Joined:
    Dec 30, 2008
    Location:
    Los Angeles
    Shooter:
    Multi Format
    For both 160nc and 400nc(I use these as well as the VC lines), I've found them to have the standard -2 to +3 latitude. Regrettably color can't be treated the same as b/w, and with the zone system, due to color crossover.

    but the -2 +3 works for me, but I try to get things within a -1 to +2, just so it makes printing, and scanning, easier in the end.

    -Dan
     
  4. Medusa83

    Medusa83 Member

    Messages:
    72
    Joined:
    Jul 6, 2006
    Location:
    B.C., Canada
    Shooter:
    4x5 Format
    Thanks so much for the help!!
     
  5. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,781
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    I have posted photo examples made over this range several times on APUG. I hesitate to do it again as it takes up storage space. I suggest that you look up either the direct negative scans or the prints from the negatives. I used Portra VC.

    PE
     
  6. hrst

    hrst Member

    Messages:
    1,300
    Joined:
    May 10, 2007
    Location:
    Finland
    Shooter:
    Multi Format
    It's usually said "2 under and 3 over" but that's marketing. 2 under may be usable but it's usually not good at all, but 3 over can be quite good. I would rather say 1 under and 3 over, or 2 under and 5 over.

    Today's films have better highlight linearity and thus overexpose latitude than before.
     
  7. Chris Lange

    Chris Lange Member

    Messages:
    780
    Joined:
    Aug 17, 2009
    Location:
    NY
    Shooter:
    Multi Format
    my father used to pull portra 400NC down to ASA 6 when he was shooting glamour and beauty, and those negatives apparently came out beautifully.
     
  8. 2F/2F

    2F/2F Member

    Messages:
    8,003
    Joined:
    Apr 29, 2008
    Location:
    Los Angeles,
    Shooter:
    Multi Format
    The best thing you can do is to figure it out yourself. Forget the in-camera metering of the composition that you will be photographing, as it will introduce too many possibilities for error. Unless the composition is a scene that averages out perfectly to a middle grey tonality, your in-camera metered exposure will, quite simply, be wrong. Use an incident meter or a grey card (and open 1/2 stop from the card for your "normal" exposure). Take a bracketed roll, underexposed all to hell through overexposed all the hell, drop it at the drug store, and get automatic 4x6s back. (If you can find a place that still prints 4x6s optically, I'd go that route instead.) The most underexposed neg that still made a decent print is how far under you can be, and the most overexposed neg that still made a decent print is how far over you can be. That is the definition of latitude. If you really meant dynamic range, and not latitude, that is another issue all together.
     
  9. 2F/2F

    2F/2F Member

    Messages:
    8,003
    Joined:
    Apr 29, 2008
    Location:
    Los Angeles,
    Shooter:
    Multi Format
    That is not pulling. That is grossly overexposing (six stops). If no changes are made in processing, it is not called "pulling".
     
    Last edited by a moderator: Dec 4, 2009
  10. David William White

    David William White Member

    Messages:
    1,179
    Joined:
    Jun 23, 2007
    Location:
    Hamilton, Ca
    Shooter:
    Multi Format
    Point of clarification (without arguing the figures quoted):

    The '7-9 stops' is a description of the total range of luminance the film is able to record, from highlights to shadows. The '-2 to +3' is the variance from nominal exposure allowed for respectable, standard prints.
     
  11. 2F/2F

    2F/2F Member

    Messages:
    8,003
    Joined:
    Apr 29, 2008
    Location:
    Los Angeles,
    Shooter:
    Multi Format
    That sounds right at first....but on further thought, it cannot be. Even when not at their best-performing ISO settings, quality digital cameras can almost match that nine stop figure these days, and considering the stop or so of headroom when shooting raw and doing the equivalent of "pulling", they can (barely) exceed it. Color neg film can record far more than 9 doublings of luminance value in a scene, as can black and white film. I know that from personal experience.

    Perhaps the 7-9 stop figure is not just talking about the film itself, but factors in the conversion to a "straight" positive print on to RA paper, without utilizing special printing techniques such as burning, masking, or multiple scanning...but the film itself can certainly record a wider luminance range than that.
     
    Last edited by a moderator: Dec 4, 2009
  12. stevewillard

    stevewillard Member

    Messages:
    178
    Joined:
    Feb 6, 2005
    Location:
    Fort Collins
    Shooter:
    Large Format
    Like PE, I also use Portra VC 160. I expose it at ISO 80 to ensure 0.15 density units above film fog at a Zone I placement when exposed in shaded light. Shade light is a cooler light and has less red then direct sun light areas. Using ISO 80 insures that any reds in shaded areas such as flowers are properly recorded and do not turn muddy.

    I also have constructed a 14 stop characteristic curve ranging from Zone I to Zone XIV using ISO 80. The curve is very straight from Zones I to XII which means the contrast is constant over that range. Zones XIII and XIV exhibit a shoulder, and the curve begins to flatten which means the contrast at those Zones is reduced. However, detail at Zones XIII and XIV are still very good.

    Basically what this means is that Portra VC 160 does a very good job at approximating the brightness ranges of the human eye. If you can see it you can photograph it. With a 14 stop range, I have no need of nor do I use graduated neutral density filters. I have shot under the most extreme mid day conditions one could ever imagine and have gotten excellent results. However, I would like to qualify that statement with the following considerations:
    • I use a UV 2A haze filter. This filter is the only filter that removes 100% of the UV radiation and is designed for high altitude shooting. It is not cheap.
    • I also use a polarizer filter to help with clouds. The polarizer will remove any glare in the scene and will increase the contrast in clouds to help compensate for the reduction in contrast at Zones XIII and XIV.
    • Printing high contrast color negatives using traditional methods with a scene range of 14 stops is a topic that needs to discussed some where else. The methods can be very complex.

    Hope this helps...
     
  13. 2F/2F

    2F/2F Member

    Messages:
    8,003
    Joined:
    Apr 29, 2008
    Location:
    Los Angeles,
    Shooter:
    Multi Format
    Good info, Steve. Thanks.
     
  14. Sponsored Ad
  15. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,781
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    Steve;

    Very good comments. I should add that I use the same filters that you do and leave them on my cameras all of the time. The only one that does not have the filters is my Speed Graphic unfortunately, but, you can't have everything.

    PE
     
  16. DanielStone

    DanielStone Member

    Messages:
    3,107
    Joined:
    Dec 30, 2008
    Location:
    Los Angeles
    Shooter:
    Multi Format
    So Steve,

    you expose 160vc at 80, all the time? I'll have to shoot a roll and see what its like.

    just out of curiosity, what type of uv 2a filter would you recommend? I have b+w filters on all my lenses, would a 2a from them be satisfactory? I've also heard of a company, Formatt, that supposedly makes super-duper filters(with a price to match). Have you ever heard of them?

    thanks for the info!

    -Dan
     
  17. nworth

    nworth Subscriber

    Messages:
    2,191
    Joined:
    Aug 27, 2005
    Location:
    Los Alamos,
    Shooter:
    Multi Format
    Color negative film has extremely wide latitude, but you can definitely tell when a negative has been underexposed or overexposed. It's more tolerant to overexposure than underexposure. You can get acceptable (well, sort of) negatives in the +3 to -2 range, but things get a bit washed out with overexposure and gritty, with little shadow detail, on underexposure. I've found you can treat color negative film very much like black and white film. Make sure you have sufficient exposure for the shadows, and the highlight will probably take care of themselves (except in really extreme contrast situations). Best results are usually near the rated speed, but I often give about a third of a stop overexposure to make sure the shadows are good (sometimes more).
     
  18. stevewillard

    stevewillard Member

    Messages:
    178
    Joined:
    Feb 6, 2005
    Location:
    Fort Collins
    Shooter:
    Large Format
    Yes Daniel, I expose my film at ISO 80 all the time. This makes sense because a scene with both extreme shadows and highlights is what I shoot most of the time. The highlights expose just fine, and I get rich detail in the shadows. A scene only in bright sun is equivalent to a scene with both shadows and highlights, but without the shadows. In scenes like this I look for a shadow some where close to the scene to meter on and give it a Zone III exposure/placement (most of the time) even though the shadow is not in the actual scene I am photographing. This allows me to let the highlights fall where there may and exploit the full 14 stop latitude of Portra VC 160.

    It is very important with color negative film that you expose for the shadows just like do with b&w film and let the highlights fall where they may. This is because the shadows are the thinnest part of the negative. Do not expose for the highlights like you do for slide film otherwise you could severely underexpose the film and not realize the full 14 stop latitude of the film.

    I shoot with 5x7 and 4x10 large format cameras and use the Lee Filter system. I purchased my filter from B&H Photo, and it is a Format filter. The price for a 4X4 inch filter is $157.50. The filter has a slight yellow tint to it, and I have had no problems with it.

    The filter I purchased came with a plastic frame. I carefully remove the frame which was glued on. The filter consist of three layers of glass cemented together. I then sanded the edges and seal them with clear nail polish. The filter is thicker then the standard filter thickness and would not slide into my Lee filter holder. I hand to modify one of the slots on the filter holder with shims so that I could slide the UV 2A filter into the slot.

    Hope this helps...
     
  19. Medusa83

    Medusa83 Member

    Messages:
    72
    Joined:
    Jul 6, 2006
    Location:
    B.C., Canada
    Shooter:
    4x5 Format
    Thanks that was really what I needed as I only shoot slide and B&W at the moment and that statement makes it much clearer.
    Thank you everyone for your input!
     
  20. stevewillard

    stevewillard Member

    Messages:
    178
    Joined:
    Feb 6, 2005
    Location:
    Fort Collins
    Shooter:
    Large Format
    The power of color negative film lies with bold vivid light which is just the opposite of color slide film. In fact, I cannot shoot with someone who uses slide film because my needs are so different. You can see some of my work on my website at www.stephenwillard.com to get an idea of what I am talking about.

    Please note photographing a bold high contrast scene is the easiest part. Portra VC 160 can do that with easily. The hard part is printing a high contrast color negative onto paper. There are two methods you can employ. They are dodging & burning and masking. I use the masking because it can be applied to very small or fragmented areas of the image that would be impossible to do with dodging & burning. However, there are two serious problems with masking high contrast negatives. They are as follows:


    1. Ghosting - This is a term I made up to describes a vivd halo that occurs where there is abrupt density differentials in the mask film sandwich such as where mountain edges meet the sky.

    2. In order to compress the brightness ranges from extreme shadows to extreme highlights I have to create mask as thick as bricks to hold back light in the shadows long enough so that the highlights can be properly printed. These thick masks will compress the hell out how of adjacent detail with similar print values. For example, detail in a mid tone region of the print can turned to mud looking flat, lifeless, and dull.

    To overcome these two problems I have had to invent whole new masking technologies in my darkroom which took me years to do and at this time is proprietary. For this reason I highly recommend that you restrict your scenes to 8 to 9 stops at the most.
     
    Last edited by a moderator: Dec 4, 2009
  21. hrst

    hrst Member

    Messages:
    1,300
    Joined:
    May 10, 2007
    Location:
    Finland
    Shooter:
    Multi Format
    Clarifying dynamic range and exposure latitude

    Terms dynamic range and exposure latitude cannot be defined without each other. For a given technology (slide film, neg film, digital) there is only dynamic range. Then, exposure latitude means the extra dynamic range for a given scene. For example, if a negative film has a dynamic range of 14 stops, and a scene you are going to photograph, has a contrast of 9 stops, you have 5 stops of exposure latitude.

    So, there is no "exposure latitude" for a given film, but rather there is "exposure latitude" for a given film AND scene.

    But, that is only a simplification. In fact, there is no perfectly linear and uniform system over the whole dynamic range. If you have 14-stop dynamic range and 9 stops of information, there are more and less optimal exposure choices to select from. And that depends on everything, again.

    Dynamic range for digital, slide film and neg film behaves quite differently.

    But I have come up with three different definitions for dynamic range, that can be used for digital or film.

    The almost linear / noiseless dynamic range -- the brightness information that shows all the very fine low-contrast detail perfectly without any contrast-increasing post-processing.

    The usable dynamic range -- all the brightness information that can carry quite fine details, so that this fine detail can be somehow seen in the final picture without contrast-increasing post-processing; or with contrast-increasing post-processing, any low-contrast fine detail can be revealed in very acceptable quality.

    The complete dynamic range -- all the brightness information the medium can record, regardless of quality and the effort needed in post-processing.

    For the good digital SLR cameras, the figures may be something like 7, 9, 11 stops. For color slide films (example: Fuji Astia 100F): 5, 9, 12. And, for colour negs..... Well, the manufacturers don't even bother to print the shoulder region in the characteristic curve in datasheets, because the linear section is already so long. The figures for color negs are something like: 11, 15, 25. This seems to agree quite well with Steve's experience.

    Today's color negs have the linear region as long as the whole dynamic range of digital, and then they have a very good and long shoulder region, that is completely extra!

    Here's a shot on Fuji Superia XTRA 400, overexposed 9 stops (thus placed almost completely on the shoulder) and contrast boosted after scanning: http://sorsa-tv.ath.cx/~antalh/tur/9ylivalotus.jpg
     
    Last edited by a moderator: Dec 4, 2009
  22. Athiril

    Athiril Subscriber

    Messages:
    2,948
    Joined:
    Feb 6, 2009
    Location:
    Melbourne, V
    Shooter:
    Medium Format
    They far exceed 9 stops.

    My 30D is capable of 10 stops.

    Newer digital SLRs are of much more, the highest is the old Fuji S3/S5 Pro at 14 stops, followed by the D3x closely, then followed by the D3/D700, 5DII and the rest closely behind that, followed by the medium format backs.




    I just developed an expired roll of some german film I got for 50c a roll at the second hand shop, 200 ISO, exposed from 100 ISO to 3200 ISO, all those shots came out looking decent so far inspect the negative.

    But I use my own custom process which incorporates a first developer for flexibility.

    First develop -> Fix -> Bleach -> Re-expose to light -> Colour Developer -> Bleach -> Fix, etc with wash in between.
     
  23. mts

    mts Subscriber

    Messages:
    361
    Joined:
    Feb 12, 2004
    Location:
    Los Alamos,
    Shooter:
    Multi Format
    Keep in mind that analog films gain dynamic range by compressing the density range in the toe and shoulder, while digital stores electrons in 'buckets' (pixels) and is essentially linear in response. The linear portion of the D-log(E) curve is usually less than the 7-9 stop full range. In digital recording the larger the buckets, the greater the dynamic range because more electrons can be stored, but at cost of correspondingly larger pixels. Our favorite analog materials are indeed impressive in their ability to record wide luminosity range. In the end however, the dynamic range that can be printed to paper and viewed is usually quite a lot less than what is recorded. At the printing stage the digital record compares with analog after one applies curves correction to render the image to a non-linear response--a result that we get automatically when we use analog materials.
     
  24. Athiril

    Athiril Subscriber

    Messages:
    2,948
    Joined:
    Feb 6, 2009
    Location:
    Melbourne, V
    Shooter:
    Medium Format
    I 100% disagree with the large photosite = more dynamic range, the opposite has been shown to be true, with progression of tech, hence D3x being the #1 sensor in dynamic range (except for the S3 and S5 - but thats similar to some films with different pixel/grain sizes mixed together), a fair bit about the D3 and D700.

    You should be able to insert a analogue compressor/limiter before the ADC in a digital camera to compress the shoulder in a similar manner and gain a bit in the highlights, the photosites do not reach saturation by the time highlights blow out in the analogue converted digital image, this should be shown by the S3/S5, which adds 2 stops to the range when the smaller photosites (1/4 the area of the larger ones, and thus receive 1/4 the photons, but per mm^2 squared, receives the same), though this isnt really a digital discussion forum.
     
  25. markbarendt

    markbarendt Subscriber

    Messages:
    7,518
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
    I think it is important to note here that a linear comparison is misleading.

    Even though it is true that the paper can't represent the same f-stop range that film can, all the detail captured in a C-41 negative, maybe even all 25 stops, are selectively printable within the paper's range.

    I would almost bet this is why Ansel used the word "zones" instead of "stops" to describe his system for exposure and printing. 11 zones in the scene are caught in 11 zones on the film and printed in 11 zones on paper regardless of how many f-stops are involved.

    Conversely, any media that we might use in a camera that can't catch the entire range that C-41 can, has absolutely no hope of printing that "lost" detail.

    This is where C-41's latitude shines. If I goof up (or I use a Holga) and miss the "correct/perfect exposure" by one stop or even three, it's no biggie; I just adjust for that when I enlarge it.

    If I miss by three stops with any other media I have lost a much more significant chunk of the detail I was after.
     
    Last edited by a moderator: Dec 5, 2009
  26. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,781
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    Well, firstoff a digital "curve" is a V Log E curve and when plotted looks just like a D Log E curve with a toe and shoulder. The Dmax is the brightnss capability expressed in voltage of the system you are using and is divided into the number of pixels that can represent a dmax vs dmin.

    In film, due to technical reasons, reversal films are rather much limited to a dmax of 3.0 or thereabouts, but negative films as noted earlier can go on up to 4.0 or higher. When making a print on paper, the Dmax is limited to about 2.0 but if you print on a print film the Dmax is 4.0 or higher just like the negative. So, a print on film Neg-Neg is the best representation of the entire tone scale of the original negative. No other system can match this, but no print films are available for common use except for Eastman Color Print film which is not matched to any consumer negative film.

    In any event, all of the above is true for color and B&W films.

    PE