Why does film stop at ISO 3200?

[Ben Kleschinsky]

It's possible to design film that goes beyond 3200. NASA designed an extremely high ISO film as I recall. I know you can push it but why

has no one designed 6400 ISO film? 12800 film?

[JDMvW]

<blockquote>

<p>why has no one designed 6400 ISO film</p>

</blockquote>

<p>Someone did. There were a few who went well over 3200 (scroll down at http://en.wikipedia.org/wiki/Film_speed ). But aside from doing weird tricks in development, they have gone the way of the horseshoe and buggy whip. They were used more for special applications and rarely for ordinary use.</p>

<p>Such speeds, for those of us who actually used the fastest film we could get, were always like a singing dog. The trick was that it could sing; no one expected that it would sing well.</p>

[Matt Laur]

<p>My dogs sing beautifully. But I'll stick with modern digital sensors when I need to take pictures of bio-luminescent invertebrates in caves, or dark brown dogs fetching brown birds from a shaded hedgerow half an hour after sunset. The new tools have become so good that I've stopped wondering about things like film speed at this point, even as mere curiosities. </p>

[aplumpton]

<p>Each medium has its pros and cons. Digital is the game for higher ISO, albeit with some other trade-offs. Enjoy film as long as you can for its reproduction at moderate and low ISO values. Apart from the pleasure and beauty of darkroom B&W prints which is the raison d'être for continued film use as an alternative, both digital and film give finest results at moderate or low ISO values. Noise is a consequence of entropy and nature. </p>

[Karim Ghantous]

<p>T-Max 400 can be exposed at EI-4, which is 6400. You lose some DR, obviously, but you'll get a better image than Delta 3200 from what I've seen. Sports photographers were pushing Fuji 400 negative film to 3200 in the 1980s. I'd say that Kodak VISION3 500T could cope with 6400, but few photographers use cine film.</p>

[lex_jenkins]

<blockquote>

<p>"T-Max 400 can be exposed at EI-4, which is 6400. You lose some DR, obviously, but you'll get a better image than Delta 3200 from what I've seen."</p>

</blockquote>

<p>I'd like to see some examples, including complete methodology for exposure, processing and printing or scanning. If the methodology is valid, it can be reproduced independently by other photographers.<br /> <br /> "Better" is subjective. I prefer the look of pushed T-Max 400 at 1600 over my results with Delta 3200 at 1600-3200. But that's because pushed T-Max has finer grain and more conventional tonality. There is no true shadow detail in pushed TMY. There is with Delta 3200 at EI 1000-1200 or so. But Delta 3200 is much grainier and requires selective application of contrast filters and dodging/burning in optical enlargements, or comparable techniques with scanned negs, to get results that I find personally pleasing.<br /> <br /> Film sensitivity is limited by physics. Film speed is limited by the size of the silver halide grains and to some extent by sensitizing dyes. The true speed - as conventionally determined by measuring density over film base plus fog - of Delta 3200 is closer to 1000-1200, and TMax 3200 is slightly slower, around 800-1000, although with aesthetically more pleasant tonality and grain. Delta 3200 tends to be very grainy and a bit low in contrast. The nomenclature for these films is intended to indicate suitability for pushing to 3200, not the true speed of these films.</p>

<p>Films faster than ISO 400 are vulnerable to fogging from cosmic rays. Over time this negates the true speed of factory fresh film, as base fog rises. There's no practical way to overcome this. <em>(The old "stored in salt mines" anecdote appears to be apocryphal, although popularly repeated online - I haven't been able to find any corroboration on <a href="http://motion.kodak.com/motion/Support/Technical_Information/Storage/storage_info.htm"><strong>Kodak</strong></a> or Ilford websites. There's a theory that such storage may have been more cost-effective effective in terms of temperature and humidity, but any purported protection from ambient cosmic radiation may have been negated by radiation from the mines themselves.)</em><br>

<br /> <br /> <a href="http://en.wikipedia.org/wiki/Photographic_hypersensitization"><strong>Hypering</strong></a> tricks have been used for astro and surveillance photography to boost the sensitivity of film, but the treatment provides only a very short duration advantage. Hypered film must be used immediately and processed immediately. Same with pre-flashed film and paper - the advantage in boosting speed is of very short duration.<br>

<br /> <br /> I've never heard or read any legitimate claims - supported with methodology that others can follow and repeat - for boosting the true speed of an ISO 400 film to 3200-6400, again, as determined by the standard methodology for least measurable density over film base plus fog.</p>

[lex_jenkins]

<p>Ilford has similar recommendations for pushing film. Like Kodak, Ilford's tips specify there will be some loss of shadow detail. It's up to the end user to decide whether this loss of shadow detail is acceptable for their personal uses and aesthetics. I often prefer the look of pushed film. But pushing - underexposure followed by compensatory developing techniques - doesn't boost true film speed, as determined by the conventional methods.</p>

<p>The reason why pushing is often acceptable for some surveillance, or low light candid photography of people, is because light to mid-tone skin often reflects enough light to allow for acceptable results with push processing. But it doesn't work as well for folks with darker skin. I've seen this myself in my available light theater photos when the cast included white, Hispanic, Asian and black actors. Darker skin doesn't record as well with underexposed film, no matter the developing technique.</p>

<p>Push processing - extended development - can in some cases improve the aesthetic tonality of midtones. Diafine with Tri-X tends to create very flat looking skin tones with relatively little gradation, especially in low contrast lighting - overcast skies, etc. But pushing with a suitable developer like Microphen or other renders more natural looking gradations in skin and other midtones. Both can produce very good results under some conditions, as long as we accept the compromises.</p>

<p>But pushing doesn't increase true film speed significantly. The most credible claim I've seen was from an Ilford rep, who reported a true speed of 500 from HP5+ with Microphen, a little better than the ISO 400 rating achieved with whatever their standard developer was (no idea what developer Ilford uses to determine ISO speed). Based on that information I tried Microphen with HP5+ for my early morning and evening landscapes. There was a slight improvement in shadow detail, especially foliage, but the noticeable increase in grain and contrast didn't suit my taste. Even medium format HP5+ at EI 500 in Microphen produced noticeable grain in 8"x8" enlargements. So I switched back to ID-11 for that usage.</p>

<p>BTW, this debate has come up before, including in <a href="/film-and-processing-forum/00ZSxv"><strong>this thread</strong></a> a few years ago. Again, specific methodology is needed in order to facilitate independent testing. That includes, among other factors, accurate incident metering of the light falling on the subject. This would help minimize the variables and subjective factors. Reflective metering - spot, averaging or matrix - allows for too many variables. It's too easy to introduce subjective biases.</p>

[JDMvW]

<p>Also, BTW, the discussion of pushing - getting high ISOs, how well do the prints look?, etc. - goes back to when ASA 400 was super-fast. It was a staple magazine article for slow months back to the late 1930s, and long before that in slightly different forms.</p>

[bebu_lamar]

<p>For 35mm film I think it stopped at 400. To me an ISO 400 film the grain is in the unacceptable category. </p>

[jim_momary]

<p>Sidenote -</p>

<p>Regarding cosmic ray shielding, an Antarctic station has a facility called IceCube.</p>

<p>At that location a neutrino detector is buried 2.4km deep in the ice.</p>

<p>Even at a depth of 7875 feet neutrinos from space are still detected.</p>

<p>(Institute for Nuclear Theory, Univ. Washington, Seattle, Wa. online document)<br /><br /><br>

Jim</p>

[Matthew Currie]

<p>A niche market for sure, but let us not forget that at a time when 400 speed Plus X was wicked fast and grainy, Polaroid's ordinary black and white film was at 3000, and they offered speeds as high as ASA 20,000.</p>

[fritz_carlsson1]

<p>Did anyone on PN, in the good old days, ever use Kodak 2475 Recording Film at ISO3200, developed in Kodak DK-50? I used it for interior and low-light grab-shots at conferences. The negatives printed easily on account of the low contrast. Provided the negs were not blown up too large i.e. smaller than 8" x 10", the grain was acceptable. </p>

[craig_shearman1]

<p>"For 35mm film I think it stopped at 400. To me an ISO 400 film the grain is in the unacceptable category"<br /><br />I always considered 400 "normal" speed rather than fast. But then I worked mostly for newspapers, where by the time the image was printed through a halftone screen on cheap paper the grain was no longer an issue. Even for portrait work, though, by the time we had films like Portra, I still used 400 and was fine with it.<br /><br />All the technical issues aside, film "stopped" at 3200 because that was as far as the R&D had made it by the time digital came along and made it unprofitable for Kodak, Fuji, Ilford and others to continue any big push on new films. Who knows what they might have come up with if digital had not come along.</p>

[User_2000406]

<p>Jim, that's neutrinos which are not cosmic rays, and which do not have any significant effect on any film unless you're somewhere in the vicinity of a supernova.</p>

[Karim Ghantous]

<p>BTW, this debate has come up before, including in <a href="/film-and-processing-forum/00ZSxv" rel="nofollow"><strong>this thread</strong></a> a few years ago</p>

<p>Indeed it has, and the issue was settled. :-)</p>

<p>I've never heard or read any legitimate claims - supported with methodology that others can follow and repeat - for boosting the true speed of an ISO 400 film to 3200-6400, again, as determined by the standard methodology for least measurable density over film base plus fog.</p>

<p>Fuji 400 negative, pushed three stops in 1985. Looks like we're going back - to the future!</p>

<p>https://dl.dropboxusercontent.com/u/45862794/Photo%2016-02-2015%2010%2058%2014.jpg<br>

https://dl.dropboxusercontent.com/u/45862794/Photo%2016-02-2015%2010%2058%2055.jpg</p>

<p>At this EI, blacks are no longer pure, but otherwise the colour holds up nicely.</p>

[Mike Gammill]

<p>Yeah, we've discussed it earlier, but since then digital has improved enough to give it enough of an advantage over 1000 ISO and higher films that unless I specifically need film for a project I shoot digital for speeds over 1000. For film in color I really like the Fuji 200, 400, and 800 films. For black & white it's Tri-X, Ilford HP5+, Arista EDU Ultra 100, and my cold-stored Panatomic-X and Plus-X. Tri-X and HP5+ can easily take a rating of 800 (for my use anyway) without too much contrast or excessive grain. </p>

[Ben Kleschinsky]

<p>So that settles it. The reason no one came out with film speeds higher than 3200 was digital came along. I also can conclude that film over the decades just like digital sensors are doing today became less noisy at higher ISO's. It is a shame that advancements in film have come to a stand still. As fair as film grain goes I prefer that over digital noise. For the professional photographer in the 21st century film has become impractical. I still love the results you can get on film though that you just won't get with digital. That is a another topic though. Thanks for informing me that this topic already has been brought up.</p>

[lex_jenkins]

<blockquote>

<p>"So that settles it. The reason no one came out with film speeds higher than 3200 was digital came along."</p>

</blockquote>

<p>Digital didn't hinder the research and development of faster films. Physics had already limited the practical application of films faster than around EI 1000 or so.<br>

<br>

Again, as stated before in this thread and earlier discussions, film sensitivity to light is limited by the size of the silver halide crystals (grain), sensitizing agents/dyes (primarily iodides and silver bromoiodide), and film base. Ultra high speed films like T-Max 3200 and Delta 3200 were already at the maximum practical light sensitivity for most applications. These films were already vulnerable to fogging from ambient radiation, primarily cosmic radiation. These films were a reasonable compromise between light sensitivity and stability for practical applications by most photographers.<br>

<br>

Occasionally surveillance films are suggested as alternatives. Most surveillance films were actually "slower" than T-Max 3200 and Delta 3200, in terms of true speed as conventionally measured by density over film base and fog. For example, <a href="http://www.kodak.com/eknec/PageQuerier.jhtml?pq-path=2608/2612/4136&pq-locale=cs">Kodak's Hawkeye Surveillance film and similar products</a> were rated with an exposure index of up to 800, beyond which push processing was recommended (Kodak's test showed T-Max developer achieved the maximum practical speed from those surveillance films). These films offered reasonably fine grain and reasonably good stability against environmental factors including heat, humidity and pollutants in areas with heavy vehicle traffic.<br>

<br>

Faster films would be impractical: excessively grainy; too vulnerable to degradation from ambient radiation, temperature, humidity and environmental pollutants and contaminants. A significantly faster film would be practical only in larger formats where grain would be acceptable relative to enlargement and print size; and for photographers who could use the films quickly before degradation occurred.<br>

<br>

And, again, this was why special techniques such as hypering were used to maximum the light sensitivity of the available practical films. But this technique was not practical for most photographers and was generally practiced only by astrophotographers.<br>

<br>

Digital simply enabled us to accomplish what film was unable to accomplish in practical applications: record images in dim lighting without resorting to special techniques or materials that degrade in storage. There was already tremendous demand by photojournalists and specialty photographers for ultra high speed film, years before practical digital cameras were feasible for the consumer market or most professional applications. It's the reason why most of us who used Tri-X in the 1960s-'80s tried magic elixirs like Diafine to wring out a bit more speed or, in most situations, a reasonable compromise between true speed and acceptable grain and contrast. For the photojournalist in the heyday of newspaper and magazine reproduction, excessive contrast with deep blacks were discouraged - it made a mess in printing and handling of the printed page. Photographers who worried only about silver gelatin or other prints for display purposes could be less concerned about deep, featureless black shadows.<br>

<br>

Keep in mind that up until around 2003 high speed film still rivaled most practical digital cameras for low light use. That changed very quickly and by 2005 dSLRs like the Canon EOS 5D were delivering very good results at high ISOs.<br>

<br>

For film manufacturers there was no incentive to pursue what had already proved impractical: a high speed film that didn't require special handling or processing and could be manufactured and sold at a cost the market would bear.<br>

<br>

If you have the time you can research the background behind film physics, and R&D considerations in books online, including <em>The Manual of Photography and Digital Imaging</em> (edited by Elizabeth Allen, Sophie Triantaphillidou), most or all of which is accessible via Google books.</p>

[eugen_mezei]

<blockquote>

<p>Hypered film must be used immediately and processed immediately. Same with pre-flashed film and paper - the advantage in boosting speed is of very short duration.</p>

</blockquote>

<p><a href="/photodb/user?user_id=172915">Lex Jenkins</a>, d'accord with hypered film, but I always was under the impression that you can preflash (to get a compression in the highlights) and this is not something volatile, it can be done anytime, even months or years before or after exposing and you can develop when you like. <br>

Please explain, why you think fogging with light must be done almost concomittent with exposure and developing.<br>

</p>

[lex_jenkins]

<p>The theory about pre-flashing film <em>(and direct positive paper - <a href="http://ilfordphoto.com/Webfiles/2010827171602436.pdf">Ilford offers quite a bit of advice regarding pre-flashing their Harman direct positive paper</a>)</em> is not to fog the film, but to "excite" or increase the sensitivity of the emulsion. This is a bit different from the theory of <a href="https://books.google.com/books?id=IfWivY3mIgAC&pg=PA151&lpg=PA151&dq=pre-flashed+film+and+paper,+reciprocity+failure&source=bl&ots=7k5rb343O6&sig=SSogkzeZyLjxw254Zec0YWVydGA&hl=en&sa=X&ei=3Qj9VI3ZEIWRyQSm14HADQ&ved=0CEkQ6AEwBQ#v=onepage&q=pre-flashing&f=false">pre-flashing conventional printing paper</a>, fogging it slightly to control contrast and produce some tone rather than featureless highlights.</p>

<p>Pre-flashing film and direct positive paper should increase sensitivity without fogging. Such extremely low light or short duration exposures are susceptible to the same reciprocity failure that affects any emulsion, although some films have better reciprocity characteristics than others.</p>

<p>Similarly, underexposed film intended for push processing should be developed promptly to avoid further loss of what little shadow detail might have been recorded.</p>

<p>I was skeptical about this when I heard it from much more experienced photographers 20 years ago. But it's easy enough to test for ourselves. Try pre-flashing film and/or paper, per the usual recommendations. Use some immediately. Wait a week, a month or longer to use the rest of the pre-flashed emulsion. Compare results. Same with underexposed film intended for push processing. Shoot half a roll (let's say an ISO 400 set for EI 1600 or more underexposure). Wait a month and finish the roll, then process it immediately. Compare the first and second halves. Those simple tests persuaded me.</p>

[glen_h]

<p>Kodak seems to have recommendation up to 3200 for TMY.<br>

http://www.kodak.com/global/en/professional/support/techPubs/f4043/f4043.pdf<br>

if you really want to, develop even longer and see what happens.</p>

 

[Dave Luttmann]

Lex, Hypering provides no benefit on short exposures. It was mainly designed as a process to elimiate reciprocity failure

in long exposures. The forming gas mixture of hydrogen and nitrogen removed moisture from the film. It did not need to

be used and processed right away as long as it was frozen in a container that had no moisture. I frequently used hypered

film within a few weeks without issue.

[lex_jenkins]

Thanks for the clarification about hypered film,

Dave. I tried it only a couple of times but

didn't have much interest in astro photography.

[glen_h]

<p>As I understand it, the physical grain of a color film is equivalent to the physical grain of a B&W film about 2 stops higher ISO. There was Kodacolor up to 1000, and an Ektachrome designed for 800 or 1600. So B&W up to 3200 seems about right.</p>

<p>But color films have the advantage that dye clouds look nicer than sharp silver grains. A color film with the same physical grain size won't look so bad.</p>