Dominic Case

I neg matched a student film I made (a very long time ago). I worked in a lab, I had access to all the gear, and thought I could do it. I passed the assignment, but the result was embarrassing. No miscuts, but dirt and spread cement was plentiful. I didn't try again. Years later, in my job, I had to figure out why we were getting bad neg cuts on some jobs. I tracked it down to one neg cutting operator, using the same equipment - splicer, cement, rewinds etc - as the other cutters. Watching him, step by step I detected a tiny difference in the sequence of operations, which no-one had noticed, or thought twice about. When he changed his practice the cuts improved. It just shows how crtitical the process is. So, sure, you can do it. But the original question was about a showreel. The results you get for yourself might not be up to the standard you'd want if it's to show you off and get work for you. It's like signwriting. Yes, anyone can paint a big poster or put a sign on a shop window. But if you aren't a trained signwriter, it'll look amateurish, and that isn't always what you want. BTW Simon, your comments might have been intended in jest (though I'm not convinced they were) but they are racist and offensive, and have no place in this forum. BTW, although drearily Anglo-Saxon, I read enough German to understand both versions of your post. But for fun I ran the German part through Google translator, and it started out thus:

That decision hurt many of their people in the field who believed that it was a well-judged replacement product (and continuation/expansion of their existing Cinema Automation programs), as the demand for print film stock would dwindle. But Kodak have been used to market domination (in film) and they don't seem to have the stomach for more competitive sectors, where they are up against other market leaders such as Christie.

I can't follow your thinking here, Simon. Yes, of course the performance of the lens is a part of the final resolution of the image, but so are many other factors, including the ability of the emulsion to record more or less precisely the image that fall on it. The original question asked whether there was anything other than graininess in an emulsion that determined its inherent sharpness. Clearly the answer is yes there is. There are a number of measures: acutance, MTF, resolution, acuity, granularity, etc. They all measure different but inter-related properties. A photographic scientist needs to use them very precisely to be sure of clarity. It is possible for one emulsion to have a higher granularity and a higher acutance or sharpness than another. It is indeed a shame that Kodak (they aren't alone) do tend to "jumble words like laymen", (there is another thread on this site that has mentioned just that) but in their marketing literature , (which is probably what was originally referred to in this thread,) they aren't writing scientific papers, they are addressing the non-scientist. They could have said "KODAK VISION2 100T Color Negative Film 5212 / 7212 is the color negative motion picture film that has the highest acutance"; or "KODAK VISION2 100T Color Negative Film 5212 / 7212 has the best MTF of all color negative motion picture films". But it doesn't have the same "snap", does it. BTW, apart from James & Higgs, and Mees (both cited above), I rely on Walls & Attridge, Basic Photo Science.

Don't get me started, John. They missed so many opportunities with that software - or, rather, with the software they could have developed with the knowledge of colour science they have, or had, in the company. But, like this little app, it seems to be designed for what it could do, rather than what would be useful. But their film stock is still an amazingly excellent way of capturing images.

Karl is right. Don't even think about doing your own neg cutting. An "old-fashioned editing bay" is not a neg cutting bench. And if you are asking about "glue" but not about a splicer, then you have the cart before the horse. Most professional neg matchers have their own splicer and treat it the way a concert violinist treats his or her instrument. By all means try editing your reel by cutting a work print. But go to a specialist neg cutter to match the neg. (Quickly before they all close up shop!). If you cut your own neg, then, I promise you, the print will show sparkle and dirt around each cut, the cement will probably spread into picture from the splices, and the picture will jump at each splice. That's assuming you make every cut at the right frame (it's easier than you'd think to go wrong there, and there is no opportunity to "uncut" the neg.).

I think John was asking abut the Technicolor plant in China. I believe it closed in the early 1990s. It opened around the time that Technicolor London closed its IB plant (late 970s). But I was told they built all new equipment for China, they didn't recycle the old machines. Although IIRC it was about the time of Nixon's ping-pong diplomacy with China, the deal was done entirely through Tech London, as there was still an embargo on US-China trade. I found some pictures and a good account of Technicolor in China here: http://www.in70mm.com/news/2010/technicolor/index.htm

I've come across descriptions of the photographic development process as being closely analogous to the behaviour of an amplifier, in particular vacuum tubes or valves. They are very similar. Interesting, but not much use as a teaching aid, as not many people understand an amplifier at the level of volts and amps, (I struggle with it myself, electronics was a new subject when I did Physics!), and of those, few want to understand development at a molecular reaction level.

The clear stock was in fact a conventional black and white positive stock, which was initially exposed with the optical soundtrack (from a separate negative, as now), and in one version of Technicolor, also with a light black and white image similar to the black ink or "K" separation of CMYK four-colour printing on paper. This improves contrast and black density. Leo Enticknap describes this well in his "Moving Image Technology, from Zoetrope to Digital", and there is a reliable entry in the Focal Encyclopedia of Film & Television. I say reliable because the editor, and author of that entry was Bernard Happe, who was for may years Technical Manager of Technicolor London, and also installed the Technicolor plant in China in the early 1970s. I never worked at Technicolor nor saw an imbibition printer, but I have worked with a number of ex-Technicolor people. It sounded like a stupendously difficult process to manage successfully, but brilliant when it worked. Of course all this is in regard to Techicolor printing, and nothing to do with their brief essay into reversal.

Monopack was a low contrast version of Kodachrome. It was processed by Kodak in the Kodachrome process, where the dyes are added in the developer solutions. Some people are comparing it to Ektachrome commercial purely because EKC was also a low contrast product, also designed for duplication and printing (whereas Kodachrome and Ektachrome both come with projection contrast in the original film. But the Ektachrome processes (low contrast Commercial ECO2 and ECO3, and normal contrast ME4) are entirely diferent from the Kodachrome process. Monopack was introduced (I believe rather reluctantly) by Technicolor, to try to produce a single film colour process (hence the name Monopack), which could, in their words "run though a normal black and white camera" instead of the enormous machine that was a Technicolor bipack camera. It's unusual these days to think of a film camera as a "black and white camera" or a "colour camera". That distinction seems to be more appropriate to early video or TV cameras.

Sinon are you suggesting that the properties of the film emulsion have nothing to do with the degree to which the image is resolved on the film? (Whether you call it MTF or sharpness or resolution, or even acutance). If you are, then, respectfully, that's also rubbish. Image spread, halation, developer edge effects, and granularity all play a part in this, and are all effects of the emulsion, not the lens.

An Australian film of the early 1990s - 'Broken Highway' shot by Steve Mason. Exposures and contrast a little wild, but compositions up to Steve's usual standard of creativity.

Oh dear (sigh). Working out a film budget, including taxes, rebates, pre-sales and so on would be complex. Working out the carbon footprint of a roll of stock would be a complex calculation. Converting running time to length (eg multiply by 90fpm for 35mm 4 perf) isn't complex. I thought at least it would include a factor for shooting ratio, but no. It's probably a handy app if you don't know the factors, but hardly complex. And by the way, the example definition (of latitude) shown on the iTunes download page is misleading at best, but I'd say "wrong".

In the 1940 Technicolor Annual Report (on the Widescreen Museum website" Hertbert T Kalmus reported: "Your company's research engineers have also been engaged in cooperation with Eastman Kodak Company on a process of photography employing a single negative or monopack instead of the three strips, and on which three emulsions are superimposed on a single support. " Lassie Come Home (1943) apparently used this stock: but it was a very unwieldy process to make prints: according to Martin Hart here, Technicolor had to "slide each of the three Kodachrome emulsions off the original base and place them on individual blank stocks for the production of matrices. "

The significant difference with Technicolor printing was that it wasn't a photographic process. The three dye transfer strips carried yellow, magenta and cyan dyes which were transferred by contact onto clear film base. More like printing newspapers. So the dyes chosen were a lot more stable and fade-resistant (as well as being more true in colour). After Kodak Eastmancolor negative captured the camera original business in the early 1950s, Technicolor continued making prints using the dye transfer process, even from Eastman negatives, unitl the early 1970s.

Can't let this stand! When the manufacturers switched to polyester base, it caused major problems with platter systems all around the world. Acetate base used to run very nicely on platters for many years. Amongother things, there were issues with static electricity build-up in the polyester base, which lead to adjacent turns of the print clinging to each other, and jamming in the feed loop in the platter. If that ever happened to acetate (rarely), then the film would break, the projector would be stopped for one minute maybe two, to relace after the break, and the show would go on. Because polyester doesn't break, usually the entire platter load (upto 12,000 ft) would be pulled off the platter and on to the floor. I've even seen the entire platter cakestand fall over. That takes half an hour or more to sort out. One theatre chain here insisted on show prints being on acetate base, as long as it was available - after a bad experience at a red carpet premiere :o It's true that polyester base doesn't suffer from vinegar syndrome, so polyester prints are a better bet for longevity. But that isn't an issue for cinema prints, which are usually taken off after a couple of weeks, and might not be used again. The switch to polyester was because the base can be recycled. Not sure what proportion of prints are actually recycled though, I know that a lot end up as landfill (where, ironically they last a lot longer than acetate ones did.

Possibly. But if you lob in with a can of stock that the lab doesn't normally use, it might take two or three tests to get it lined up on the printer. And while I think of it, a considerable amount of stock is needed to line up to print analogue soundtracks - especially if it's a new batch or different manufacturer. That certainly can run to thousands of feet, though once a level is established, routine testing is more economical. And while all the manufacturers' print stocks are theoretically process-compatible in the ECP2 process, there are invariably fine-tuing differences that become important when you are running high-speed machines. They carry different amounts of water, for example, so the correct drying setting for one stock could be inappropriate for another. Yes, labs do routinely use both Kodak and Fuji (and, in this country, Agfa-Gevaert as well): often the distributor mandates which stock a feature is to be printed on, purely for cost reasons (the cinematographer doesn't usually get a look in at this deal).

Probably nothing more than the inherent American need to be different ;) In the UK, I believe that 50Hz was settled when the National Grid was first hooked up when(obviously) there was a need to standardise the frequency. And I believe that was in the 1920s, but I suspect it is probably a more complicated story than that. It's actually a testament to SMPTE that the 24fps cinema frame rate (and other standards) remained universal for so long. If it was the Society for Mains Power Transmission of Electricity, things could have been more uniform.

There's a Catch 22 in your time machine plan, Phil. Going back over 57 years, you will need to set the destination time on your machine quite accurately. You need to arrive at the relevant NTSC meeting promptly. A quick calculation tells me that drop frame vs non-drop frame can account for roughly 20 days and 20 hours difference - that is, possible error in your calculation. Now, you'll need to be sure you've got that right AND allow for 13 or 14 leap years since then. As well as the time difference across the Atlantic. If you can do all that, then you can probably solve the problem today without going back. Where were you during the Y2K scare? :lol: And by the way, what genius was responsible for setting British mains frequency to 50Hz half way through the last century, thereby setting a natural frame rate of 25fps for PAL TV, when cinema was already by then standardised at 24 fps? Or vice versa? Couldn't they see that the two numbers would eventually need to be the same? :P

David could be right. But this seems to be the same problem that comes up with 3-perf 35mm, with 21 1/3 frames per foot. I seem to recall that this flummoxed most of the neg matching software around in the 90s. The solution involved defining a reference frame at the start of a shot by the position of the Keycode reference dot relative to the top perf of the frame. You don't need to see the actual way the computer referrs to a given frame, so ugly counter-intuitive number sequences aren't a problem. (At least not any more than they are in 3/2 pull down, dropframe timecode, or days of the month for that matter.) In the case of 65mm, the defining issue is to know which footage numbers in a sequence actually have 00 frames. The next two won't, but where to start??

These are dailies, not fully corrected final images. It's quite likely that the transfer operator saw an underexposed image and chose to brighten it up so that you could see clearly what you were editing. Film captures a wider tonal range than you normally see on the screen, so there is always scope for correction. Don't underexpose more next time - the dailies will simply come back brightened up a little bit more still, and you'll end up chasing the dailies down to zero exposure :unsure:

Fine theory, but in practice quite a lot of light does get through. As otheres have said, the image is several stops under-exposed, and very red, because the remjet layer is in fact a very dark red (hold a bit of rawstock up to a very strong light and see.) That's correct. The construction of colour negative film (from the top) is* blue-sensitive layer (forms yellow dye in the processed negative) yellow filter layer (to stop blue light getting any further blue and green sensitive layer (fomrs magenta dye) blue and red sensitive layer (forms cyan dye) film support (the base) anti-halation layer (insoluble remjet carbon) (*simplified - in fact most stocks have at least two layers for each colour, and there are other lubricating layers etc) The reason the red and green sensitive layers are also blue-sensitive is that all emulsions are fundamentally blue-sensitive: the other colours are picked up by some clever trickery with dyes. It's possible to supress the blue sensitivity, but it comes at the cost of quite a lot of speed. SO it's much easier to capture the blue light on the top layer then filter it out. When light comes through the back of the film first, it is filtered quite heavily, and mostly red light gets through. It exposes the red-sensitive layer first, then that's about it. Any traces of green and blue light that get through the remjet will expose the next layer. Red, and the race of green will get through the yellow filter, but as the top layer only sees blue light, it won't get any exposure atall. So you get a very dark red image. Red highlights, black midtones and shadows. Out of focus, and mirror-reversed.

The specific details of photochemical bleach-bypassing are a function of the chemical process, not a function of any creative requirement. With digital manipulation you can produce an almost infinite range of variations to the image. A small subset of those variations would map onto the limited effects you can achieve photochemically. I can't see any reaon why exactly replicating a photochemical look digitally would (necessarily) be a useful thing to do. So why not take advantage of the extra range of control, and make the picture tell exactly the story you want it to. In a way, photochemical bleach bypass is like a bugle - you can only get certain notes. Can I make a slide trombone sound like a bugle? Not really, although I could maybe play The Last Post on a trombone, but why would I? Just read this from John - IMHO, it's the only reason you'd want to exactly simulate bleach bypass digitally. BTW we had to do something a little similar (about 13 years ago IIRC). The production (a feature) was going to use Bleach Bypass in the IP, and needed to see rushes (mostly standard video in those days) with the BB effect. We put through one roll per week of test clips from the week's shooting, making a BB interpos, dupe neg and print. And we gave the rushes colourist a reel of the tests and he came up with a pre-set on the telecine that matched the effect. Then he just set the machine up to that every night. At the time we reckoned it was the first telecine ever to have a "bleach bypass button".

Well, I thought I'd missed this list for a while - so I log in, and find this going on! How can I stay out??? So no, Brian, I won't support this argument. I might agree that if you push 50EI film one stop then as far as mid-range density is concerned, it's equivalent to using 100EI film. But the effect is very much less at lower light levels, so it's not the exact equivalent (even just in terems of exposure) of a faster stock. The Kodak explanation you cited puts it about as accurately as one could wish for. I'm not sure that I am 100% with David either, though I agree that in simple terms, no amount of developing can reveal an image detail that hasn't been captured in exposure. Elsewhere you (Brian) said: Exactly so. And there is a wide range of grain sizes in any emulsion so that even in very low light levels there will be some grains that are big enough to capture the required number of photons to make them developable. This "sufficient exposure" is really the crux of this argument. Is it a fixed amount,or does it vary with developing time. What a developing agent does, is react with ALL silver halide grains. It happens to react with exposed ones quite quickly, and unexposed ones very slowly. Longer development time (forcing) means that exposed silver grains are more developed, so forming more developer by-products that in turn couple with the colourless couplers to form more (bigger, more intense) dye clouds. It also means that more "unexposed" grains will be developed, leading to some dye clouds in the unexposed areas and a higher d-min or fog level. Meanwhile, though, the question in hand is whether more development will also dig out those grains that got sub-threshhold exposure for normal development, and give them a life that will distinguish them from still less-exposed ones. In other words, does the threshhold of exposure (enough to produce the first hint of density above d-min) vary with development. I think the answer is yes, but not as much as you'd think. That is really what the Kodak quote is saying. However, is the original question about whether the cinematographer with the Bolex (remember him, a few post ago??) should force process or look for correction in DI. If he was counting on seeing deep deep shadow detail, then he should push process. If he was simply wanting to avoid an "under-exposed look" with flattish shadows and poor contrast then he will be able to recover from that perfectly in the DI grade. And incidentally, he will avoid the increased graininess that the push process would result in.

The "actual grain size" is a hard thing to quantify in any film, possibly even harder in a reversal film. What you actually have in the processed image is dye clouds that are formed wherever silver grains were not exposed and formed in the first development. What the film starts with is a very broad range of grain/crystal sizes. The largest ones are exposed first, the smaller ones are only exposed by brighter light: so the average grain size is also dependent on exposure and density. For another thing, dye clouds tend to cluster together, so aren't the same thing as discreet grains at all. And looking for the "average" isn't even as easy as looking for (e.g.) the average height of an adult human, which follows normal distribution (a bell curve) over a very limited range. What is the average size of a fish might be a better analogy. BUt this link is one that discusses the metrics that are usually used to measure these things, such as rms granularity and resolution in lppmm: http://cool.conservation-us.org/byauth/vit...tal-projection/ By and large, K25 was pretty fine-grained for its time, but I think a medium speed negative film would give it a good run for its money today. (Given that its hard to compare neg with reversal for the reasons above).

You can do. There are a lot of small points to consider: There are differences in the perforations that might lead to a slightly unsteady image (different perf shape and size in 35mm, same shape in 16mm: different pitch in both gauges). You will, of course get a negative image, so you'll still need to transfer or print it to make a positive. It will be very high contrast, and therefore the latitude will be minimal - in fact, less than nothing: you will have blocked shadows or burnt highlights or both, and even a half-stop of exposure change will make a significant difference to the image you get. Print stock is balanced for a quartz halogen printer lamp, and for an orange-masked image, so you will need an extra orange filter to get anything like a neutral balanced image: one way is to shoot in daylight with two 85 filters. Without them you get a very strongly blue balance. All print stock is now on polyester base. It's unbreakable, so if your camera jams, it is likely to get damaged. To be honest though, I've never experienced this problem actually happening. But I've seen the results of a polyester print jamming in the projector/platter system. Nasty! You'll need to negotiate a processing price with a lab before you start. You'll need to find someone to sell you a short length, wound onto the right core: print stock comes from the manufacturer in 2,000 to 6,000 ft rolls.