THE USE OF STANDARDIZED H. & D. CURVES IN SENSITOMETRY
BY O. E. CONKLIN
Du PONT PATHE FILM MFG.CO., PARLIN,. J.
Journal of the Royal Photographic Society, 53, p. 127; 1913
Thank you for a truly in-depth explanation which covers all areas. I always knew that QC existed from the earliest days (film: i.e., 1889) but QC is not always QC I am certain that you can understand. One can have rather stringent requirements but, still, there are troubling deviations. I was after the ultimate QC, if I dare phrase it that way. Perhaps, that 'event' happened even before the thirties.Wall, author of “Photographic Emulsions” (1929) discusses the topic of quality control. E. J. Wall was active in the dry plate and film industry going back to the 1880s, and shared the experience of his career in this and other books.
The discussion is mostly in the context of how lot to lot differences in gelatin needed to be accommodated by sample batch testing as the sensitization of emulsion pre-1920s depended on impurities in the gelatin. When a company like Eastman received a new order of gelatin, the first step was characterization and adjustment of the emulsion formula for the new gelatin lot. This was even within the confines of their preferred (for consistency) gelatin suppliers.
That was a lesson learned the hard way, and it is well documented (Eastman’s biography) that lack of testing almost bankrupted the fledgling Eastman Dry Plate company a few years after its start. Once he got past that problem, Eastman introduced key quality checks in his dry plate manufacturing process: demands on suppliers, frequent, periodic testing, etc, in addition to the coating quality inspections in place from when he started coating dry plates in his mother’s kitchen. In fact, that major problem he had with his dry plates led to the one of the first major tasks of his R&D division, led by Mees at its inception at or near the turn of the century, of isolating the sensitizing impurities in the gelatin. This was accomplished by the 1920s, but long before then — mid 1880s — Eastman at least had strict quality control to ensure consistency of sensitivity.
Let me say that this isn’t a difficult task. I do the same for my dry plate emulsion. So it was easy to implement some quality testing procedure even before the H&D curve was devised.
In addition, Wall discusses the control of coating flaws in detail and the apparatuses for addressing them. As for timeframe, IIRC he touched on progress since the days of dry plate (1880s) and film (1890s), so this was all actively being worked out and solved before 1900. From there, the primary QC task was to maintain the *same* level of quality while more complex emulsions and faster production throughputs were being realized in the 20th Century.
In the early days of dry plate commercialization, it was said the Seeds Dry Plates were considered the best, highest quality dry plates on the market. That was a major reason why George Eastman bought them out. I’ve purchased several unopened boxes of Seeds Dry Plates, from various periods in their company’s history (primarily pre-1895), to evaluate the quality. They are indeed very good, and you simply cannot achieve that good a coating without quality control.
-Jason
Hi David,
yep, I think you hit the nail on the head there. A couple additional thoughts to add context:
Quality control in the past was driven by customer / manufacturer expectations: What is “good enough”? In the 1950s era United States, tied to the post-WW2-era trend of standardization (to streamline the ramp-up of industry in case of war), the expectation of quality was codified in standards and specifications. Those standards have been consistently updated — ISO standards today, particularly ISO 9001 in a generalized industry sense — so you can actually go out and find what aspects of quality control the manufacturers adhere to, both from a general manufacturing sense as well as specifically applied to the film industry.
As an engineer, in the more general sense, I tend to shudder at the massive juggernaut of QC standards... not from the “necessary evil” perspective, but more from a “this is codified basic common sense and thus shouldn’t be necessary” perspective. But... I’ve been around long enough to understand that quality control as codified in specs and standards is a mutually beneficial “shared experience” of industry, and helps the progress (and safety) of technology in a good way by displaying the art of the possible. I like to think the scientific and technical community shares that sentiment. As for standards and specifications (of which QC is one part), it allows for universally understandable technical communication. “35mm film” actually means something, and isn’t arbitrarily defined from manufacturer to manufacturer.
Yea, this. The “Yellow God”! Their quality and range of products was amazing. When I was growing up if you wanted the best you bought the yellow box. I used all sorts of off brand, “expired” materials from Freestyle, but when it counted I always used Kodak.Consistent high quality minimizes waste and therefore maximizes profit when production volumes are high.
And at its zenith, Eastman Kodak produced very high volumes.
It is important to understand as well that Eastman Kodak made a lot of money selling chemicals, paper and (to a lesser extent) equipment to labs.
If the film you make for photographers is inconsistent, your lab customers will end up with unhappy customers of their own.
You said exactly what I wanted to say, but much better. I used to order 16mm 10 rolls at a time from Kodak with emulsion numbers on box, but since I shot a variety of subjects outdoor it didn't really make much difference, but for a major studio production small variations would be noticed by audience.In terms of motion picture film I would argue the opposite- that QC was much more critical from roll to roll. When editing requires film from different rolls to be abutted to one another it is critical that they match. There is an awful lot more flexibility when printing still frames. Back when movies were still shot on film a production would buy all the film from a single emulsion batch before shooting started to minimize variance.
I would also say that in terms of the early motion pictures you have seen there are a myriad of factors that influenced what actually you got to see. My first introduction to silents was probably the 16mm prints I saw at a pizza parlor when I was a teenager. Poor worn dupes of old prints I suspect, and they were run at the wrong speed. Quite awful from a IQ standpoint but wonderful films. A few years ago I saw a gorgeous restoration of FW Murnau’s “Sunrise” in a high def format. The cinematography and IQ was stunning- we sometimes get a false impression of what films looked like in the early days. Sorry to get a bit OT.
You make a very valid point with the editing requirement. - David LygaIn terms of motion picture film I would argue the opposite- that QC was much more critical from roll to roll. When editing requires film from different rolls to be abutted to one another it is critical that they match. There is an awful lot more flexibility when printing still frames. Back when movies were still shot on film a production would buy all the film from a single emulsion batch before shooting started to minimize variance.
I would also say that in terms of the early motion pictures you have seen there are a myriad of factors that influenced what actually you got to see. My first introduction to silents was probably the 16mm prints I saw at a pizza parlor when I was a teenager. Poor worn dupes of old prints I suspect, and they were run at the wrong speed. Quite awful from a IQ standpoint but wonderful films. A few years ago I saw a gorgeous restoration of FW Murnau’s “Sunrise” in a high def format. The cinematography and IQ was stunning- we sometimes get a false impression of what films looked like in the early days. Sorry to get a bit OT.
I would say with motion picture film, they had that nailed by the early 1910's for black and white (of course) film.
Adjusted for inflation, films have always pretty much cost the same amount (as far as media, processing and so on) since the very early silent era. It was, and is, still an astronomically expensive medium to produce and bad quality film was not to be tolerated...
How were nitrate projections different?You said exactly what I wanted to say, but much better. I used to order 16mm 10 rolls at a time from Kodak with emulsion numbers on box, but since I shot a variety of subjects outdoor it didn't really make much difference, but for a major studio production small variations would be noticed by audience.
But silent films during silent era were shot on crystal clear nitrate base. Long ago, maybe at MOMA in ealrly 1950s, I saw a couple films projected on nitrate and the effect was stunning. A noticeable difference between results from nitrate and safety film.
In terms of motion picture film I would argue the opposite- that QC was much more critical from roll to roll. When editing requires film from different rolls to be abutted to one another it is critical that they match. There is an awful lot more flexibility when printing still frames. .
It would be interesting to delve into the ongoing REASONS for the determined level of QC. ALL will admit that perfection is a level which can, theoretically, never be fully achieved. So, it comes down to the interplay of 1) common sense, 2) dollars, and a 3) theoretical underpinning which holds perfection as a 'godly' religion for its own sake.
In its latter years, Kodak almost achieved a synergism of the three. But, WHY? I think that the reputation of Kodak was such that to be less than truly obsessive would have been economically, socially, and industrially counterproductive. Few who are not of my age, or close to it, can begin to understand the level of status that that corporation was tethered to during the mid and latter 20th Century. - David Lyga
I cannot confirm what you say here concerning film prices matching inflation rates.
When I was in my mid 20s living in New York in the mid 1970s, 100 feet of B&W 35mm film cost $8. At the time, minimum wage was slightly above $2 per hour. NOW, there are jobs in New York paying as little as $10 per hour (despite the national minimum wage currently being $7.25). Thus, from 1975 to now, wages have appreciated by about 5X. Try to buy 100 ft of fresh Tri-X for $8 X 5 = $40. Not possible. - David Lyga
As far editing, a simple scene of a conversation likely is shot with a set up for one actor, and then the reverse shot is set up for the second actor. each of them likely on a different roll of film (the old 90ft a minute speed chews though a lot of 400 ft rolls.) and all has to mesh perfectly when it gets edited, so the audience is not thinking about the editing. It is unlikely that the two shots can have exposure timing done between them, and making an inter-positive would show, so the two shots have to match perfectly.
Shot exposures have always been timed (graded) for film-based motion pictures; that's what I do. However, I will say that each shot is usually quite consistent and if I have a Long shot, medium shot and two close-ups, they tend to be exactly the same point value throughout the scene. Of course, some films have sections of scenes re-shot for editorial purposes and those shots can vary to a degree. .
It would be interesting to delve into the ongoing REASONS for the determined level of QC. ALL will admit that perfection is a level which can, theoretically, never be fully achieved. So, it comes down to the interplay of 1) common sense, 2) dollars, and a 3) theoretical underpinning which holds perfection as a 'godly' religion for its own sake.
In its latter years, Kodak almost achieved a synergism of the three. But, WHY? I think that the reputation of Kodak was such that to be less than truly obsessive would have been economically, socially, and industrially counterproductive. Few who are not of my age, or close to it, can begin to understand the level of status that that corporation was tethered to during the mid and latter 20th Century. - David Lyga
No, indeed, there are (were) many firms with a strong commitment to QC. The reason I earmarked Kodak was because in the 50s, 60s, even 70s, they were the dominant force. They were truly ubiquitous, not merely another player, like today.But, David, it sounds like if you were implying that only Kodak achieved a high degree of QC.
I have used hundreds of rolls from Agfa, Kodak, Ilford and Fuji though my life, and never had any QC issue attributable to the film manufacturer. Even occasionally i used films from Foma and Tura (Tura AG, germany),and no problem. The only time i had QC problems were with 120 Lomography films which had the well-documented backing paper issue. And this was Kodak film ("Lady Gray" is rebadged Tmax 400)
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