I am curious about the history of Emulsion speeds.

What was the iso of the first commercially available film? was it 8 or 12iso? and from this starting point what were the next speeds available and who reached the benchmark for fastest films of their day?

Who was first to make 32iso film? first to reach the 50mark? first to 100?, 200?, 400?, 800?, 1600? 3200? what companies reached the highest iso's first? and when did they do it? Also what were the benchmark products which broke the speed barrier called?

Technically speaking, those first films wouldn't have an ISO rating. ISO was introduced around the 1980s and became prevalent some years later. Those films would have equivalent ISOs though. They were rated in Scheiners, H&D's, and then later, Weston, DIN, GE, at least until ASA came along.

sorry my bad, but in these terms who was the who of the speeds? and what was their product called?

ZorkiKat actually the ISO speed can be equated to its sub-components which do have a much longer history. ASA/BS and DIN. an ISO 100/21° is in fact 100ASA/BS 21°DIN, these aren't an equivalent because they are exactly the same. In the early 60's the ASA/BS system changed doubling the film speeds, the DIN system was always more accurate for practical use.

Ian

ZorkiKat actually the ISO speed can be equated to its sub-components which do have a much longer history. ASA/BS and DIN. an ISO 100/21° is in fact 100ASA/BS 21°DIN, these aren't an equivalent because they are exactly the same. In the early 60's the ASA/BS system changed doubling the film speeds, the DIN system was always more accurate for practical use.

Ian

ISO equivalents (or 'translations') for older values -those which antedate the ASA systems- NOT the reassignment of ASA into ISO.

For example, a 1920s NC film would perhaps have a given speed of 250 H&D.
In a modern, ISO-driven context, the 250 rating would sound fast. But when 250 H&D is converted to ISO, it would only be between 8-6.

When the photo-electric exposure meters started coming, there was no standard index yet. So they devised their own: GE and Weston assigned their own values to films (with some cooperation with the makers - for instance "fast" Dupont Superior-3 from the 1930s had a speed of Weston 64, and GE 56). Eventually the makers of both films and meters came together and devised standard indeces like the ASA, which came about in the 1940s.
Weston 64/GE 56 was around 80 ASA.

This 80 ASA contained a 'safety' factor which allowed for discrepancies in the real film speed, as well as meter and shutter/aperture differences. Some overexposure was allowed. The safety factor was removed by the 1960s so that original 80 ASA became 160 ASA- the "improved" Plus-X of the time sped up to 160 from its original 80, but eventually became officially 125.


The DIN system wasn't always that accurate. The different systems in use determined emulsion speed various ways. For instance, DIN was at a time based on exposures which gave an 'optimal' density aim point with prolonged development in a GIVEN type of developer . That wouldn't make the speed index too accurate if the developer in question wasn't available or used. In a 1954 issue of "Leica Fotografie", a writer suggested that the DIN system be revised "in a manner that will have regard to the type of development that is normal to everyday practice".

There was also the "Kodak" speed and a host of others.

It is difficult, if not impossible to answer this question as we cannot even make those old emulsions with reliability today. It is safe to say that based on the exposures I have seen, an ISO range of 3, 6, 12, 24 and etc was evolving from near 1900 onwards. Kodachrome at 10 in the 30s was a step back, as it was color and color film always was slower than B&W film for technical reasons.

PE

In my lifetime, there has been only one bump on the maximum speed scale and that was in the 80s with the introduction of P3200 and Ilfords similar film. For some reason the ISO of P3200 is a secret that you can't find on Kodak's site. I don't have a calibrated sensitometer, but in a relative speed comparison of P3200 against T-Max 400 I found it to be about one stop faster. They do show a characteristic curve here, but the axes are a little crude to determine the speed clearly. http://www.kodak.com/global/en/professional/support/techPubs/f32/f002_0518ac.gif

Having said that I copied this from the internet and claim no responsibility for its content:

Tri-x goes back to WW2 in sheet film; something that the Kodak historians fail to grasp. It is in their own Kodak databooks of the WW2 period as an asa of 200 daylight; 160 in Tungsten in 1945. Roll film tri-x; and trix the breakfast food came out on 1954; maybe the Kodak historians ate too much trix; and lost a decades worth of history. Super-XX was the fast roll film before 1954; then tri-x in roll film came out. Super-XX lived on for many more decades

Hummm,

You know of course, Kodak admits this is not really an ISO 3200 film, but rather one, ah hum, adjusted to give, uh, favorable results if pushed to that speed.

IIRC they identify it as an ISO 1000 film.

Don't forget that Polaroid introduced a 3000 speed film in 1959. At the time, it left the competition in the dust. It is still my favorite...now as the Fuji FP-3000B incarnation.

Any film emulsion when coated on paper support, will give at least 1 stop in speed from back reflection and another stop from the high coated silver level. In actuality, the 3000 speed film was about 800. Kodak had a 3000 speed instant product ready to go when they lost the lawsuit to Polaroid and it was never introduced.

Kodak does indeed indicate that their 3200 film is only very pushable, but then the same is true of the Ilford product. Neither have a true 3200 speed. The highest practical speed is about 800 - 1000 due to keeping. The highest true film speed ever achieved was 25000 and that was done two ways at Kodak. The second was recent, and posted on APUG, the first was only done internally. Keeping on the first material was extremely poor and on the second is unknown as it was only created for lab speed tests.

PE

Any film emulsion when coated on paper support, will give at least 1 stop in speed from back reflection and another stop from the high coated silver level. In actuality, the 3000 speed film was about 800. Kodak had a 3000 speed instant product ready to go when they lost the lawsuit to Polaroid and it was never introduced.

Kodak does indeed indicate that their 3200 film is only very pushable, but then the same is true of the Ilford product. Neither have a true 3200 speed. The highest practical speed is about 800 - 1000 due to keeping. The highest true film speed ever achieved was 25000 and that was done two ways at Kodak. The second was recent, and posted on APUG, the first was only done internally. Keeping on the first material was extremely poor and on the second is unknown as it was only created for lab speed tests.

PE

Polaroid made a 20,000 speed film: Type 612 (http://www.rwhirled.com/landlist/landfilm.htm#P100); it was designed for CRT reproduction. I have no idea what its keeping properties were like, although I imagine they would be pretty bad. I also don't know what the EI is, but I suspect it would be pretty close to the rated speed as you can't really push Polaroid films the same way as you can with normal films.

Thanks for posting this.

I am very fuzzy at the moment, but from what Ron was saying, the emulsion used would probably have had an ISO of about two stops less... but perhaps PE can fill us in more completely on how this works in a polaroid product... that is, how and where the negative fits into the picture, (is the negative backed with a reflective coating??) plus how the extreame contrast affects the sensitivity, if at all.

Member Gigabitfilm once tried to estimate the speed of the Kodak NO.1 Camera System and he assumed a speed of 50 ASA.
(To my understanding he used different films in the camera and compared shadow detail of the resulting prints with prints of the time.)

The Polaroid 612 film had a reflective backing IIRC. Polaroid 667 has a paper backing like all the Polaroid peel-apart films. I once tried a 15 years expired pack of 612. The pods were still good but there was no image.

IIRC they identify it as an ISO 1000 film.

Thanks, I could not find that in the datasheet on the Kodak site.

Member Gigabitfilm once tried to estimate the speed of the Kodak NO.1 Camera System and he assumed a speed of 50 ASA.
(To my understanding he used different films in the camera and compared shadow detail of the resulting prints with prints of the time.)

Yes, speeds of ancient films could be elucidated from photographer exposure notes based on the brightness of the sun.

Polaroid made a 20,000 speed film: Type 612 (http://www.rwhirled.com/landlist/landfilm.htm#P100); it was designed for CRT reproduction. I have no idea what its keeping properties were like, although I imagine they would be pretty bad. I also don't know what the EI is, but I suspect it would be pretty close to the rated speed as you can't really push Polaroid films the same way as you can with normal films.

This is a paper based oscillographic recording material. Kodak made the Ektaline 2000 series papers which were similarly very fast and for the same reasons I described above. They were by no means 20,000 true speed due to gaining some of their speed via reflectance from the paper support.

These products came in long rolls 5" and 10" wide for a variety of "instant" processing machines and were used in huge quantity by Cape Canaveral to record instruments during launch. They were also used by geological surveys and etc., as the papers were more reliable than the inked recorders.

IIRC, they relied on high intensity UV light for exposure and had little visible sensitivity, but my memory may be faulty on this. I know that in the 60s, I was sent from the Cape to Rochester to view the new E2000 setup that was being introduced to compete with the CEC processor which had about 1/2 the speed and sensitivity. Polaroid had no competing product at that time, but Dupont reportedly did. I never saw that product, but we did use CEC stuff until the Kodak product was in full production (CEC = Consolidated Electrodynamics Corporation).

I have a full mental history of high speed papers. AAMOF, the ISO rating of Ilford MGIV is 25 in-camera, even though the emulsion is really only about ISO 6 or so and my ISO 40 film emulsion is ISO 100 - 200 on paper. Even so, a 20,000 speed paper would be a fast emulsion, but who cares about grain and sharpness on a paper?

I did not say a high speed paper could not be done. I repeat, a 20,000 ISO true film emulsion is the highest that has been made. One of the experiments showed it to have very very poor keeping. Results are not in for the newer Gilman emulsion. In the former, you would not like the grain or sharpness, but in the latter, both are pretty good.

PE

Somewhere I saw a time chart showing how film speeds increased from the late 1800's to the 1970's. The chart also showed how camera use changed as speeds increased and hand held use became more practical, this is when emulsion speeds reach the equivalent of 32-50 ASA (ISO).

Ian

C'mon Ian, we did a lot of hand-held Kodachrome 35mm shots that were taken at ASA 10.

PE

Note I said "more practical" Ron, but a 10 ASA film in a pre-war hand held roll-film or sheet film camera with a typical lens of max aperture f4.5-f5.6 would be pushing things . . . . except on very bright sunny days :D

Ian

C'mon Ian, we did a lot of hand-held Kodachrome 35mm shots that were taken at ASA 10.

PE


Somewhere it's been said that many Leicas from the original Kodachrome era
were "stuck" at f/6,3 @ 1/50sec. For exposures in good daylight. F/6.3 gives good DOF for the average snap-shot , and 1/50 is a stop faster than what's generally considered the limit for hand-held cameras.

Note I said "more practical" Ron, but a 10 ASA film in a pre-war hand held roll-film or sheet film camera with a typical lens of max aperture f4.5-f5.6 would be pushing things . . . . except on very bright sunny days :D

Ian

Box cameras which were meant to be used hand-held rather than on tripods were already around before films sped up to more than ASA 10. They had slow maximum openings of f/8 or f/11 and a fixed shutter speed at around 1/25. Lots of snapshots were made- so it meant that hand-held shooting with very slow films wasn't an impossibility. People did make their snapshots in good, not necessarily very bright, sunlight for obvious technical reasons. But then again, that's where the things that they were interested in shooting was- at least more often than not.

Note I said "more practical" Ron, but a 10 ASA film in a pre-war hand held roll-film or sheet film camera with a typical lens of max aperture f4.5-f5.6 would be pushing things . . . . except on very bright sunny days :D

Ian

Ian, I had two box cameras that were used to shoot a lot of ISO 10 and 25 color back in those days. I also have a Kodak Stereo camera that is indexed in terms of Kodachrome 10 film and I took a lot of shots with it.

The stero camera was excellent outdoors and had a small flash unit for indoors. I have boxes of steros, and had a lot of trouble when the ISO 25 films came out.

But, on the whole, I agree with you, that it was pushing things. Underexposures were very common.

PE

Thanks, I could not find that in the datasheet on the Kodak site.

Publication F-4016, "KODAK PROFESSIONAL T-MAX Films", contains the following on p. 19:

The nominal speed is EI 1000 when the film is processed in KODAK PROFESSIONAL T-MAX Developer or KODAK PROFESSIONAL T-MAX RS Developer and Replenisher, or EI 800 when it is processed in other Kodak black-and-white developers. It was determined in a manner published in ISO standards.

Thanks, I could not find that in the datasheet on the Kodak site.

I found this quote on page 19 of f4016 (2007 version - might be the same as the one on the website now):
"The nominal speed is EI1000 when the film is processed in KODAK PROFESSIONAL T-MAX Developer or KODAK PROFESSIONAL T-MAX RS Developer and Replenisher, or EI800 when it is processed in other Kodak black-and-white developers. It was determined in a manner published in ISO standards. For ease in calculating exposure and for consistency with the commonly used scale of film-speed numbers, the nominal speed has been rounded to EI800. "