Home of Professional Cinematography since 1996
85 & 85b filters
class="Paragraph">Well then here is the question:
class="Paragraph">If I expose a shot in daylight (gray scale/color chart in frame) with tungsten balanced film using:
class="Paragraph">1. AN 85
class="Paragraph">2. An 85b
class="Paragraph">3. With no filter. (compensating for exposure of course)
class="Paragraph">Will the lab be able to correct them all to BE the same? Won't the difference in the spectral components of the light reaching the film make a difference on the negative? One that we can see even when the shot is corrected to the same gray scale? Anyone done such a test, anyone know the answer?
class="Paragraph">Once upon a time Cinematographers performed strange rituals in which they would expose film with various filters, look at the film, and draw conclusions which would further their experience.
class="Paragraph">What happened to the day when we didn't do what everyone else thought was right and actually tried something out for ourselves. Some of my best work came from my own experiments. Also some of my greatest failures. I often laugh when someone asks the question "what is that stock like or what does that lens look like?" That's like describing the work of Michael Angelo over the phone. I'm not saying this is the norm, but lately I sure see a lot of it. Lately it's less legwork and more join the club. It seems sometimes like the art of cinematography is merely paint by numbers.
class="Paragraph">There will be some differences in look when you shoot without the 85 and have the lab correct it in printing. Without proper filter correction, your blues get over-exposed (or denser on the negative) and the reds gets under-exposed (or less dense.) Visually, this will make your reds less saturated, meaning that fleshtones will lose some of their color saturation (although this can be more pleasing in some cases.)
class="Paragraph">I usually shoot indoor daylight scenes with an LLD filter instead of an 85 onto tungsten stock, and I find that my fleshtones are a little more pastel, but in a pleasant way. But once I shot a scene and later found out that the window glass that the HMI's were shining through had a blue tint; even though I had used an LLD, my image was quite blue and when I timed it back to "normal", the fleshtones in the scene went pretty monochrome (although nobody else watching the print noticed this.)
class="Paragraph">Not only that but If I'm not wrong isn't an 85B the proper correction for 3200(deg)? There's 200(deg) thrown right out the window at the get go...
class="Paragraph">Steven Poster ASC
class="Paragraph">Your absolutely right! It takes an 85B to bring 5500K to 3200K (Tungsten balanced emulsions). I always use the 85B for my shoots. However, this brings up the following question: Why is it then that Kodak charts, like the ones in field guides, or the charts in the AC manual, always recommend the use of an 85 to convert 5500K to 3200K and not an 85B?
class="Paragraph">Only Ektachrome films get an 85B correction on Kodak Charts.
class="Paragraph">As a documentary guy usually working wide open in low light conditions, I have a tendency to use a #82 filter. You don't lose anywhere near as much light as with a #85, and it gives a better look than using nothing at all and correcting exclusively in printing.
class="Paragraph">After doing a test of filters a number of years ago, I'm not so sure it's that important that our 85's match perfectly.
class="Paragraph">I did a filter test where I would shoot a scene with say an 85 on one half of the 35mm still frame, with the other half covered. (Actually using a Cokin split frame attachment.) I would then spin this device around and expose the other half of the frame with a filter that I wanted to compare to the first filter. Even though I was using regular still color negative film and having the prints made at a one hour photo shop, I could still make a valid comparison because both sides of the print had received the same printing exposure and development.
class="Paragraph">For a test comparing 85 type filters, I would of course first put a overall 80A filter on to turn the daylight color negative film into a tungsten film. It got a little tricky correcting for the various filters so that density would be even between the two sides.
class="Paragraph">What amazed me was that a Chocolate filter, which certainly looks very different then an 85 correction filter produced virtually the identical correction as an 85 filter!?
class="Paragraph">I've also seen "85" filters from still photography manufacturers that looked much browner then our customary Tiffen/Kodak "orange" filters.
class="Paragraph">I came to the conclusion that the visual look of a correction filter was not necessarily an indication of it's ability to do it's job ...
class="Paragraph">Well, since spectral sensitivity curves are not linear and color negative films have to "cheat" the spectral response of the dye layers (thus the orange masking) my *guess* is (and it's just a guess) that a straight 85 IS providing the proper correction to the dye layers.
class="Paragraph">Also the spectral distribution of sunlight or ay other blackbody is non-linear, so it's always a question of "matching the curves" - 5500K is a _nominal_ color temperature - "photographic daylight" which is equivalent to a so-called *typical* daylight situation, actually described as a mixture of sunlight and skylight with the sunlight predominating. (An EK booklet I have says photographic daylight is based on "average summer sunlight at noon in Washington DC" ! )
class="Paragraph">A 200 degree margin is significant at 3200 deg. but is relatively insignificant at 5500 deg.
class="Paragraph">The Ektachrome films were always rated for 3200K, only Kodachrome is 3400K.My guess here is that EK felt 3400K lamps would give less magenta in skintones, in home movies and slides. Also some 3400K lamps are designed to with envelopes to reduce UV transmission.
class="Paragraph">Anyway I don't think magenta in skintones is much of an issue these days - in fact 3200K lamps with 3200K stock looks too cold to many of us, hence all the warming straws etc etc..
class="Paragraph">Sorry Sean - you've gone crazy! They always required an #85 not #85B for basic colour correction on those ECN stocks (3200K) You're probably (like me) from the halcyon days of reversal colour where the #85B was the recommended correction for the 3400K stock like '42, '40, '50 and Kodachrome 40.
class="Paragraph">From what KODAK tells me and others this is true - the ECN 3200K balanced stocks are designed for a Wratten #85 filter for daylight correction so that correctly exposed - in theory you'd get a printer light of 25:25:25 to the LAD standard. But then that's only the theory!
class="Paragraph">The bottom line is always do what looks good!
class="Paragraph">That's not how I remembered it so I fished out Kodak H-1 (Selection and use of MP films, 1976), Eastman Films for the Cinematographer 1994 and some K 40. Here's the story they tell.
class="Paragraph">Kodachrome 40 is an A type film: ie it is balanced for 3400K Photofloods and an 85 is the correct filter. Ektachrome '52 and '44 (Super 8) are also quoted as being type A.
class="Paragraph">The Kodak literature gives '50,'40 and '42 as type B, ie balanced for 3200K. An 81A is suggested for use in 3400K light and an 85B for daylight. I'm not even going to mention type G Ektachrome.
class="Paragraph">The filtration for all negative films, daylight and tungsten, is given as the same for 3200K and 3400K, ie 80A for daylight and none for tungsten.
class="Paragraph">I asked Don Strine of Kodak about the use of the LL-D filter with Vision stocks (I haven't got round to trying that combination yet). His reply was that because modern neg stock has such a long straight section on the characteristic curve there is not so much need for it (or an 85 by implication) now as there used to be - because the print can be made away from the toe and shoulder. That's the key to the whole issue, isn't it?
class="Paragraph">That's why you can't correct reversal film so well at a later stage. If the mid tones are corrected the highlights tend to turn orange. This effect was deliberately used the other way round to give blue skies were there were none for a wartime film made in a lifeboat somewhere up North (the name escapes me).
class="Paragraph">Maybe the 85 is suggested for historic reasons - it is the correct filter for Kodachrome 40A and that is all that really matters!
class="Paragraph">Continuing the Filterspotters tone, interestingly enough Kodak suggest the 80A for using daylight neg film in tungsten (ie 3200 to 5500K). This is about 1/3 of a stop denser than the already dense 80B. Why not just use the 80B? It gets more exciting by the hour.
class="Paragraph">Sorry to bring up a stale topic but I have just received a reply from the Kodak Gurus (Geoff Whittier, John Pytlak, Steve Powell, Fred Knauf and Ron Lorenzo) about the filter question.
class="Paragraph">Although they could not give us a definite "This is the reason why", the general consensus is the spectral sensitivity difference in the two films.
class="Paragraph">If you look at the spectral sensitivity curves of the two products (Ektachrome and negative films), there is a noticeable difference in the yellow forming layers at the 400-380 wavelength range. Comparing an 85 and 85b filter, the most significant difference falls in the same range, thus the belief that the 85 filter was chosen over the 85b. All commented that either filter would produce acceptable results and only a very slight difference in look. John went as far as suggesting the only difference was in the taste of the people who originally prepared the data sheet information and all agreed that john was not far from the truth.
class="Paragraph">I hope this is of some interest
class="Paragraph">Keep in mind that transferring reversal to tape is not new. For many years all film intended for television...news, documentary, current affairs, commercials (though not to the same extent) ..originated on reversal stock. News especially because of the turnaround time to get it on air. I many cases the film was shot, processed and edited and then projected through the old film chains directly to air.
class="Paragraph">I think every cameraman should spend some time shooting nothing but reversal stocks....it is the greatest way to really learn the subtleties of lighting, exposure, tonal variation, color and Film to Tape. If you think it's tough getting negative to tape through an Ursa Gold and DaVinci you should try it sometime with reversal on the old RCA Telecine chains....I am sure some of my old mates from the ABC (Aust) and BBC Documentary teams know what I mean.
class="Paragraph">Exposure accuracy was extremely critical as there was no safety net as is the case with today's low con negs.
class="Paragraph">Given all that, shooting reversal for telecine does require a modified approach but the results are quite spectacular, as everyone has commented, especially on the Fuji reversal which I believe is essentially based on their Velvia still stock.
class="Paragraph">I think we should all meet in Washington DC at mid-day for the Summer Solstice and at the exact time shoot filter tests.
class="Paragraph">We could then sell them to Tiffen and Kodak and make an Interactive CD Rom...or better yet maybe we could set up a Web site and put all the technical parameters in there so people might end up totally confused by it all and then we would be the only guys who would know the REAL truth.
class="Paragraph">Then all this would become proprietary and we could make lots of money and spend days in Museums looking at wonderful works of Art and marvel at the fact that these guys had never heard of 85 filters but still managed to get it right.
class="Paragraph">Actually, I've heard there's a rare night-exterior Vermeer that was painted indoors but with daylight-balanced paint. The owner tried to correct it later in retouching but could never quite get the reds right, and there wasn't very much contrast to begin with.
class="Paragraph">So they took all the color out of it and released it as a sketch...
class="Paragraph">Ah... Isn't Rembrandt the one who MADE UP his own additional light sources to suit his own needs? Can't you see the man setting up his own little oil Tweenie off in the far corner of Night Watch? -- "Hang on folks, just stay right where you are, just need this one last detail..."
class="Paragraph">The following was translated from a little known parchment relating to a discussion between Rembrandt and one of his many patrons:
class="Paragraph">Patron: "You're killing me, Remmy baby, you're killing me! I can't stand like this all day and these costumes are costing me plenty!"
class="Paragraph">Rembrandt: "Just one more candle... I need to add one more candle..."
class="Paragraph">Patron: "Just sketch it in, I'll have one of your students fix it later!"
class="Paragraph">Rembrandt: "But this is the third time I've painted this portrait! Always time to do another painting but never enough time to light one more candle..."
class="Paragraph">Patron: "Hey, I can hardly see into those shadows, add some white, will 'ya?"
class="Paragraph">Rembrandt: "Always with the shadows... next it'll be too much perspective..."
class="Paragraph">Patron: "Yeah, what's with that foreshortening stuff? I paid for everything in this room and I want it all to look BIG!!!"
class="Paragraph">Rembrandt: (sighing) "Time for the large brushes and a gallon of thinner..."
class="Paragraph">I am impressed with the discussion on the use of 85 and 85-B filters. A little history lesson might be appropriate in light of the wave of post production and computer imaging currently riding the crest of popularity.
class="Paragraph">First, let me say, that now as in the past, science had been unable to manufacture a variable "RECEIVER', be it film, tape, television, pixels, etc. All color receivers manufactured to capture visual images are each color balanced for "ONE" Kelvin temperature. The one for which it was designed.
class="Paragraph">The first color films were introduced to the industry back in the mid 1930's. Type "B" films were color balanced to tungsten light (3,200K). A very important point of reference, since the light was known, had a standard Kelvin temperature and was measurable.
class="Paragraph">Even though film emulsions were all over the lot, in those early days the industry needed to convert tungsten films to daylight. The first conversion filter was a #83. (A medium orange color).
class="Paragraph">As the emulsions became stable, Eastman Kodak discontinued the #83 and introduced the 85-B. The nomenclature contained the complete use for the
filter. An 85-B for use with Type B films rated at 3,200K.
class="Paragraph">The next film venture was the manufacturing of Type A films, color balanced to 3,400K, that required less color conversion and gave birth to the #85 filter.
For those of you who keep adding the #81 series to your #85, you should check your film and filter relationships. A straight #85 is 200 degrees "Color Short" for converting 3,400K rated films to daylight.
class="Paragraph">As for using no filter and color correcting in the lab, my personal view has always been to correct in the camera. You might ask Why? Well --- The energized light carrying an image from a scene to the receiver when measured with a Kelvin temperature meter, is a mean average. Conversion filters correct the mean averages, but some points of light are warmer than the average and some points of light are colder. It is these slight color variations that give "LIFE" to color pictures.
class="Paragraph">When correction is performed in the lab, it's the same as painting the entire scene with a paint brush. The original image is overlaid with an optical color coating. The results are acceptable but stagnant. The color coating does not mix with the light of a scene.
class="Paragraph">How about the use of 85-C filters, that equals 1/2 of an 85? It converts 3,800K to daylight for use in late afternoon, when a full 85 conversion would be too warm.
class="Paragraph">One more point of information; The original 85 type A nomenclature was shortened to 85-A then to 85. They are all the SAME filter.
class="Paragraph">As for the 85-B and 85-C, these have no secondary name or symbol.
class="Paragraph" Hank Harrison
class="Paragraph" Harrison & Harrison Filters