Dominic Case

John's doing better than mpanc1. But there's another one that's relevant too. ????

David's advice here is excellent - (and it doesn't slow him down much;-) ). For an example, look at the recent thread on bleach bypass. Couldn't hope for more thorough yet concise answer. But - that's a question that gets asked on these forums about once a week - I reckon everyone on the list should be able to answer it now. here's a simple question to tell what your approach to filmmaking is (anyone). What does IP stand for?

That's generally good. I guess you are in an air-conditioned environment. It's important to make sure that the rolls of film have equilibriated to the cool dry conditions before you seal them in the bag. If you put them in bags before that, you will probably seal in a higher level of humidity: then as the temperature drops, the relative humidity will increase even more - bad conditions for the film. Also, if there IS any reason for deterioration due to damp, which can cause Vinegar Syndrome to start, then fumes will build up inside the bag. Venting or molecular sieves as John P recommends are useful for long-term stability in those conditions.

Most labs will keep your negative for as long as the production is current - it's easier for making further prints, remastering etc. But after it's all over, there is no reason why they should house the negs for ever. All of all their customers' negative would take up a great deal of expensive storage space. So most labs will have a vault suited to short-term storage - a year or so. The conditions for long-term preservation won't be any better in the lab than anywhere else. However, as you say, cool & dry is good. Stable conditions are good - not too much temperature fluctuation. Store film as you would store wine. (Maybe the lab that Laurent uses in France knows a thing or two!)

0 EV is 1 lux (about 0.1 fc) In still photography this requires an exposure of 1 second at f/1 on 100 EI film. That's the nominal starting point for this scale but not very useful. It's simply a scale of stops you can read off your exposure meter. If the light halves or doubles (one stop) then the EV changes by 1. With aperture, it's a factor of x sqrt-2, with speed it's a factor of x2. Moving up the scale, that means that 10 EV is ten stops brighter, which is 1000 lux (about 100 fc) so it requires 1/30th sec at f/5.6 on 100 EI film. (i.e. 5 stops of speed and 5 stops of aperture) or 1/50th sec at between f/4-5.6 (for motion picture cameras) etc

CRIs were notoriously difficult in every respect. Apparently Kodak threw away more stock than they sold as it failed one QC test or another. In the lab it was hard to process uniformly: you are likely to see the edges of the film printing up a lot bluer than the middle (or you will see a yellow band down the middle, dependng on how the print or transfer has been graded). That uneveness seems to be worse after a number of years, so I guess the fading might be differential across the width of the film. When it was first introduced it seemed great: one stage duplication instead of the two-stage IP/IN. And it was much better than the intermediate stock of the time, but when Kodak introduced 5243 (around 1980 at a guess) it was in turn much better than the CRI stock, which wasn't ever upgraded. Also, CRI dupes, if printed on a contact printer, were the reverse geometry to an original or a normal dupe neg, and so resulted in non-standard prints (i.e they had to be projected emulsion facing the lens rather than facing the lamp.) If that's the case with your 16mm CRI, you may need to refocus the telecine. Or, if the neg is double perf, you could run normally and flip the image electronically.

Yes. You can often answer these questions intuitively by going to the extreme. For example, moving the reflector a great deal further away would quite obviously reduce its effect (for instance, 50 meters away!) So distance IS a factor. But it's not quite the same as the normal inverse square law for point sources. In this case we are talking about a large field of illumination. Your reflector behaves the same way as a bank of lights forming a softlight. What is important is how large an area it appears to the subject. Move it closer, or make it larger, either way you get more light on your subject.

Many years ago Kodak maintained a monopoly on processing Kodachrome. Then the courts ruled that they had to release the formulas to the commercial labs. So they did. As far as I know, a few tried to run the process for a while and then gave up as it was so complex. It's a different type of process from Ektachrome, in that the dyes are added from the developer, rather than being in the emulsion in the first place. That allows them to use different dyes, which is why it's such a superb stock: but it's clearly too hard for the average home darkroom. Quality doesn't come easily!

If you have time, it would be worth sending a note to Blain Brown (via the publishers, Focal Press) to draw his attention to this error. It's incredible how simple errors like this can slip through every check and double check in the system, (and not even be noticed by any reader for a couple of years!). These days publishers can often fix up minor typo corrections like this in the next print run (I'm sure there will be one for this book), without waiting for a new edition. I'm saying this as an author who has also had errors pointed out in my books. It's mortifying to discover them, but better in the long run!

No! You've got the second rule wrong. You are quite right about the inverse square law: distance x2, light x 1/4. Correct. Now for every 1/2 x light, you need one extra stop of exposure. So for 1/4 x light, you need two extra stops. This only works for flooded lights. If they are spotlights or focussed beams, the light fall-off doesn't obey the inverse square law. The cosine law: Basically, if you have a flat surface facing a light source, then a beam of light is spread over - say - one square meter of the surface. If you turn the surface at an angle to the light (or move the light round to one side), then the same beam of light is spread over a wider area of the surface. (This one IS easier to see with a spotlight, and the law does work better for spots or distant sources). If the same light is spread over a larger area, then it can't be as bright in any one spot. The greater the angle, the more spread-out the light. It turns out that the cosine is the factor you need. Easier to get a spotmeter and measure it. Clue for understanding cosines (if you insist!): to reach a 10 ft high window, you need a 10 ft ladder at 0 degrees, but if you lean the ladder at an angle, you can't reach as high. The height you can actually reach, divided by the length of the ladder, is the cosine of the angle it's leaning at.

An Angel at my Table was shot in 16mm (Stuart Dryburgh was the DoP) in NZ in 1989-90, and blown up to 35mm for release. It was in general well-exposed, but I don't recall any deliberate overexposure or such to create a vibrant or saturated look. If you are judging by the "internet digitised version" then it's anybody's guess what has happened to it since it was on film - when it looked fabulous for a 16mm originated show at the time. Amelie on the other hand, was on 35mm and went through a digital intermediate (at Duboi in Paris if I recall) to get the rich warm colours in some sequences. Not much in common there as far as the stock and process is concerned. Nor in the look of the final product - on film at any rate. What you see on the internet or production stills isn't much of a guide.

ENR only applies to print film. Like ACE from DeLuxe, it isn't strictly Bleach Bypass, but has a similar result (retained silver). ENR and ACE both work by redeveloping the silver image after the bleach bath has removed it, but this doesn't work in the ECN2 process - whereas true Bleach Bypass simply eliminates bleaching altogether. Beware of any process that offers "partial" bleach bypass in the negative. In theory it seems easy (reduce the bleach time to a point where the silver is only half converted). In practice this "half" is very hard to control reliably, and is a different amount for different stocks etc. Your results will be unpredictable. In your testing you should experiment with yur lighting ratio. The shadows will probably block up more than you expect, so you will probably need more fill than you would think. And bracket your exposures around one or even two stops under.

Here's anamusing site that effectively demonstrates why there's NO solution to multiple aspect ratios. http://www.widescreenmuseum.com/flikfx/loatest1.htm

Not so. While IP and IN are expensive elements, you would have to do them anyway - unless you are making a very small number of prints from the original neg. So the only true additional cost is for the blow-up surcharge for whichever stage you blow up. Compare that - not just with the saving in stock cost - but also the processing, not to mention cheaper camera hire, faster set-up time etc. In 35mm (or S16) if you plan only to print from the original neg, for goodness' sake make an IP as soon as you approve the answer print. It's your only protection against damage to the original, and as someone else pointed out, it's the best thing to make a video master from. No need to spend $ on a dupe neg until later, and then only if you have to.

Most professional motion picture film is shot on negative. After editing (and negative matching to cut and splice the camera negative to match the edit as required), prints are made. A print is the positive image film that runs through a projector. It works because photography works that way: exposed film gets darker, not lighter, resulting in a negative image (dark sky, light shadows). A print from that is actually a negative of a negative (two negatives make a positive). Reversal film uses a more complex sequence of chemistry to produce a positive image on the camera original film - ready for projecting directly. However, since most filmmakers hope to make more than one copy (!), they will need to make prints anyway: so it makes sense to stick with the basic negative/positive system. It's commonly recognised that reversal film does give a slightly more "saturated" image, and so occasionally cinematographers wil choose to shoot on reversal to achieve that look. What is "saturated?" It's a measure of the purity of the colour: if you start with a totally pure red, like a stop light, and mix it with grey, you are desaturating it. A totally desaturated image is really a black and white image. Turn down the chroma control on your TV (it might even be called "saturation") to see what it means.

It helps if you say where you are when asking about facilities or services. You have to ask yourself: "why would someone offer a discount for a small job - especially when the word "experimental" is used?". If you can think of an answer, then you are ready to ask for a deal! But you have to accept that most places would discount on 100,000 ft before they'd discount on 1,000 ft.

I quite agree with Dirk that you don't really get much increase in speed by push processing. If you measure speed in the scientific way, you would find that there was only a slight increase in actual speed (the exposure needed to reach a certain density above d-min when processed to a certain gamma etc etc). The d-min goes up - though not as much as the mid-scale densities - which reduces the measured amount. What you get, by pushing, is an increase in mid-scale density that is equivalent to the loss in density caused by under-exposing. That means that you can print the negative at the same light as if you had exposed and processed normally, and see a roughly correct image. As the d-min is increased slightly, the blacks are a little less black, and that may allow you to see very slightly more into the shadows without having to print lighter. But (as John says) it's certainly not as much as a stop.

Dirk gves good answers to all 5 questions. Also, 1. ECN2 is the standard process for all colour negative stocks - from Kodak and also from Fuji. There are indeed different bleach formulations, and slight differences in fixers: but developer is developer. 2. Kodak sources its chemicals from the open market (even dedicated things like the colour developer agent CD3): many labs mix their own chemicals - to Kodak specs - using raw chemicals also sourced from the open market. Good labs normally analyse the resultant mixes to check that everything is in order: and analyse the working solutions regularly too. 3. Not between good labs, all of which follow Kodak specs quite closely and participate in Kodak programs to monitor their results against Kodak standards. Regular sensitometric testing ensures that the final results are consistent and compatible. Labs might vary slightly in detail on any given day, if - for example - they adjust the pH of a solution slightly to compensate for some other variation: or increase the development time by a couple of seconds to offset a slight chemical drift. Tolerances are tight though - to within 0.1 degrees, and about 2 seconds. 4. The overriding aim is for the look of the negative to remain consistent over a long run - and to be the same as the reference standard. Some DPs occasionally run a test through several labs to pick one: the differences, if any, tend to be in the colour of the work print or the transfer, (or the efficiency of the service) rather than in the negative. 5. Kodak have a couple of labs around the world. Most noticeably they own Laser Pacific in LA. If John Pytlak is around, he might mention the Kodak Image Care program - which is a quality assurance program that exists to allay any fears of variability in labs.

Pushing refers to an increase in deveping time, in an attempt to compensate for under-exposure. (It's a compromise at best). Obviously you can't push (or pull, ie iunderdevelop) part of a roll. (The lab couldn't even cut the problem shot out of the roll and process it separately, because no-one can see the image to cut it, until after processing.) The standard process is usually controlled to within 0.1 of a degree temperature, and within 1 second of the normal dev time (3 minutes). Pushing one stop is about a 20% change. Lab processing machines operate on a continuous basis, with several thousand feet of film passing through each chemical solution in turn. In order to vary the process for push processing (sometimes also called forced processing), it's necessary to run several thousand feet of dummy leader into the machine before changing the speed, or temperature, etc. That takes a lot more time than ususal - hence the surcharge you invariably have to pay for push-processing. Printing up, or correcting on telecine, are different processes - theydon't affect the negative at all. Don't refer to that as "pushing" - it's only confusing to do so.

If you plan to use the edge numbers (Keykode) for neg matching, then yes. Not all neg logging and matching software copes with edge numbers that run downwards instead of upwards, and even if they do, it's not always reliable. Also, if you rely on a barcode reader to scan the keykodes, then it won't be on the right edge of the film. It's not a matter of the camera taking double perf film (they all will) - it's a matter of the filmstock itself. If you use double perf stock, then your only problem will be the edge numbers. If you use single perf stock, you will have to double rewind. As far as winding exactly 100 ft is concerned, do a dummy run first with some junk film (your lab will have some junk film.) Measure 100ft, then count how many turns on the winder it takes. It will be the same number of winds every time. Best bet is to rewind the entire 400 ft first onto a 400 ft spool, then wind back 100 ft at a time from that. That's better than cutting to 100 ft on the first winding as you handle the ends less.

Panchromatic emulsions had been available throughout the 1920s, but were more expensive. Most film was still shot on ortho (blue & green sensitive, red-blind) until sound came in. Studio lighting was often mercury arc light: bluish, but too noisy for the sound recordist. So the studios switched to tungsten lights, with more red content, and therefore had to switch to panchromatic stock. That wouldn't have been an issue for newsreels at that time though, as newsreel sound was mainly narration/music (or exterior live sync sound - newsreels tend not to be shot in studios!). So I'd guess that they could still have been using orthochromatic for a little longer. Use a cyan filter as John suggests. It will darken faces, particularly lips, and lighten skies. That would probably be the most distinctive "look" adjustment that you could make. Have a look at some 1929 newsreels to see if they have that "ortho" look.

The simplest general answer is YES. Especially if you are going for a blow-up to 35mm. Less so if you are finishing only for video. The main thing is to avoid underexposure - so adding 1/2 to 2/3 stop is always safe. In the shadows. The biggest grains in the emulsion are the ones that are exposed with least light. So, more exposure adds a few smaller grains to the shadow area - and ensures that you have enough density in the negative to print or transfer with good black shadows. Overexpose and print down (see above).

John says, cautiously . . , Say I have scene of 7 stops brightness range. Based on the normally understood uesful exposure range of colour negative ofabout 11 stops (for Vision2), I can vary my exposure by 2 stops either way (more typically one under or three over) and still get back to an identical image by correcting the neg on telecine or in the printer. If I shoot another 7 to 10 stops over that, I don't think I would expect to be able to correct the image back to normal. BUT I WOULD be able to recover some sort of tonal information even at the extreme highlight end of the range. I think that is what the technical paper published in SMPTE journal reported - presumably quite accurately. It's perhaps misleading to see this precise, objective, almost forensic type of information presented in a pop way on a flash website.

I'd have thought (given the immense amount of knowledge that David draws from, and the clarity and thoroughness of his email answers) the advantages of the third edition (Malkiewicz & Mullen) over the second (Malkiewicz) would be obvious. (No reflection on Kris's excellent book, but two heads are better than one!)

very roughly half the features are shot anamorphic, 2.39:1, and the other half are widescreen, which is officially 1.85:1, flat (in other words, spherical lenses, not anamorphic). However, these are usually exposed to cover the entire negative area (1.37:1), but framed for 1.85:1. So if they are screened with a 1.85:1 projector mask, that's what you get, but if they are screened with a higher mask (1.66:1 or even 1.37:1), you get that on the screen. In other words, there is image information on the filmabove and below the 1.85:1 mask that ought to be cut off but can be projected if the mask doesn't cut it off.