William Stull: Lens Coatings, 1940

From American Cinematographer, Non-Glare Coating Makes Lenses One Stop Faster by William Stull, A.S.C (March 1940)

For many years photographers have accepted the fact that a considerable proportion of the light that enters a lens never reaches the film. The greater part of this loss is occasioned by reflections from the various polished glass surfaces- inside and out- that make up the lens, and it increases with the increase in the complexity of the lens' design.

Thus the loss is considerably greater in many of the modern, complex high-speed lenses than in the simpler, older objectives. But since lenses depend for their action upon the use of many highly polished- and therefore reflective- glass surfaces, it has seemed that nothing could be done to avoid these losses.

Almost exactly a year ago, two Eastern research groups, working quite independently of each other, separately announced the development of methods of treating glass to eliminate surface reflections. That this created a sensation in photographic circles would be to put it mildly.

Here was the development so radically advantageous that it would practically revolutionize photography! But the excitement subsided when it was learned that in both cases the project was still in the experimental stage: that while lenses could be treated, the treatment was extremely delicate and not at all lasting.

Paramount Pioneers

Today the subject takes on renewed interest when it is learned that the stage of commercial practicability that the Paramount Studio has been using a set of treated lenses on actual production, with such excellent results that treatment of all the studio's lenses is being contemplated.

The process used is that developed by Dr. John Strong of the California Institute of Technology. Essentially, this consists of depositing upon each of the glass surfaces treated an ultra-microscopically thin chemical film. This film measures but four millionths of an inch (0.000004 inches) in thickness- exactly one-quarter the length of a light-wave.

As light falls upon this film, rays are reflected from both its upper and lower surfaces. Since the coating is exactly one-quarter wave-length in thickness, these reflections from the upper and lower surfaces are equal in intensity, and opposite in phase. What follows is similar to the well known interference effect in that these oppositely phased reflections cancel each other out. However, classic scientific theory does not account for the fact that with this treatment there is an increase in overall light transmission, which would occur if these reflections merely offset each other.

Some of the processes announced a year ago, produced this coating by immersing the glass surface to be treated in a tank of liquid on the surface of which was an infinitely think film (one molecule thick) of an insoluble soap.

Forms Permanent Coating

Repeated immersions or dippings, approximately 22- built up the desired quarter-wave-length coating. It was still, however, a delicate, soapy film, with all the inevitable drawbacks of a soap-film.

Dr. Strong's method, however, is different. In this, the desired surface coating is deposited by evaporation in a vacuum. Instead of a soap-film the coating is a metallic fluoride. While the details of the Strong process cannot, of course, be given as yet, it may be stated that the present treatment produces a coating sufficiently durable to withstand any normal handling.

Some of the lenses used at Paramount have been washed to remove accidental fingerprints, without in the least disturbing the non-glare coating.

In addition, exhaustive tests by the optical experts of the studio's engineering staff indicate that the treatment is in no way harmful to the normal optical qualities of the lens. It is non-corrosive, non-tarnishing, and does not pit or scratch the glass surface. It is further stated that the expense of treating lenses is not prohibitive.

The practical advantage gained from using treated lenses are many. Probably the most startling is the increase in effective speed. Normally there is an average light-loss of 5.22 percent from reflection for each air-to-glass surface inside or outside the lens: thus with a typical high-speed motion picture anastigmat like the Astro "PanTachar," which has eight such glass-air surfaces, the loss of light from reflections is in excess of 41 percent.

If such a lens is treated on all its external and internal glass-air surfaces, this loss is reduced to negligible proportions.

Increased Shadow Detail

But this accounts for only part of the actual gain in speed. Much of this reflected light finds its way back to the film as scattered, fog-producing light which tends to veil the shadowed areas. With this scattered light eliminated, it is possible with a given exposure to record a great deal of shadow detail which is normally lost.

Conversely, it is possible to obtain a given effect, as measured by shadow detail, with considerably less light than would be needed to give the same effect with an untreated lens.

These two gains are cumulative, and add up to a practical increase in speed of virtually one full stop, or between five and six printer-light settings in the Paramount laboratory. Thus a normal f/2.3 lens, when treated is the equivalent in speed of an f/1.6 objective, but still retaining the depth of field, definition, and optical quality of the f/2.3 design!

The elimination of the internal reflections gives a marked increase in the apparent definition of scenes photographed with treated lenses. The effect may be compared to that seen when using a fast lens with and without an adequate sunshade. The picture as a whole is visibly more crisp, and details not previously evident are suddenly revealed.

In the same way, depth of field is apparently considerably increased by the treated lens. It is quite possible that the circle of confusion is affected, since the resolving power is known to be increased.

Shooting Into Lights

Every photographer is familiar with the lens-flare which ordinarily results from shooting directly into strong sources of light, such as the sun or a studio lamp. The reflections from the several glass-air surfaces of the lens produce multiple, distorted images of the light-source or the iris diaphragm, usually with strong secondary halation streaks.

Comparative scenes filmed though treated lenses show an almost complete absence of these effects. Instead, a surprisingly clear image of the scene and the light source is obtained: such halation as is present is obviously photographic rather than optical, and attributable to photographic overexposure and to reflections from the film base itself.

The practical advantages which this treatment offers to cinematography can be well imagined. The increased speed can be of tremendous value in simplifying lighting. The increases in depth and definition should be of almost equal benefit under modern conditions, especially in the case of "follow focus" and dolly shots.

It may be mentioned, too, that insofar as can be determined as yet, the use of treated lenses should be equally feasible in natural color cinematography, in Technicolor or an other process. While a treated lens, if examined in the hand, by reflected light, appears to have an iridescent magenta sheen, the coating does not appear to have the slightest effect upon the actual color transmission of the lens, nor upon its color correction.

Other Uses

The visual image viewed on the focusing screen of a camera shows no trace of color alteration, and monochrome tests of standard color charts made under identical conditions with treated and untreated lenses show no difference in color rendition. It may therefore be assumed that the treated lenses may be used equally well in color photography; and due to the inherent limitations in speed and definition of all color processes, they could be used to even greater advantage in color than in monochrome.

Naturally , this non-glare treatment need not be confined solely to motion picture camera lenses. It will be equally beneficial when applied to the lenses of still cameras, optical printers, projection lenses, and the like, while the advantages to be gained from applying the treatment to the optical systems used in recording and reproducing sound, where speed and extreme resolving power are so necessary, should be equally revolutionary.

Wide Exterior Night Lighting in 1923

From American Cinematographer, Startling Electrical Comparisons in 'Hunchback' 1923 and 1939 by Earl Miller (February 1940)

No Inkies in 1923

In 1923, incandescent lights were not used for motion pictures. The street set was a few feet longer and wider than the one used in the 1939 production. There were only fifty-six 24-inch sun arcs in the entire industry in Hollywood.

We needed every one for our night shots, and Universal arranged to rent all but one. Every night for seven long weeks all the sets in other studios were stripped of 24-inch sun arcs. They were loaded on trucks and hauled to Universal. We used them until 5am, but had to return them to the proper studio and have them set and ready to burn by 8am.

Whenever possible, we left the lights on the trucks all night instead of building parallels. This accounts for the number of trucks showing in the panoramic picture accompanying this story.

Every light used in the 1923 production was an arc. Some of the 24 inch had automatic feed, but in addition to these there were more than 450 other arcs, all of which were hand fed. All lights had to be trimmed at least twice every night and some three times.

Yes, we actually shot every night, all night, for forty-nine straight nights. At one time (and it would be the time it rained the hardest) my crew and I worked five days and six nights straight, rigged all day and shot all night; never took our shoes off; cat-napped between shots.

Six Months' Work

Finally on June 3, 1923, the last reel was in the can, and in spite of all the work and worry everyone who worked on or in that picture will tell you that we had lots of fun making it.

Here are a few of the electrical statistics:
(8) portable generators
(2) 300kw stationary generators
(6) 150kw transformers

The peak load was approximately 37,500 amperes.

Good Advice Never Gets Old

From American Cinematographer, Camera Technique Dominates Filming Results by Claude W. Cadarette (January 1940)

Every movement of the camera must have a definite purpose behind it, and if it is done without a good reason you are just retarding the tempo of the picture.

note from ryan: This is not something I learned today, but a truth that was retold from an article written over 70+ years ago! It's quite frustrating that such advice and wisdom has been around for so long, yet legions of new filmmakers and directors insist on camera moves with no motivation or justification. What Claude failed to mention, is unjustified camera moves not only slow the tempo of the picture, but the tempo of the production. Elaborate dolly shots can cause longer set-up and execution times.

Good Stuff on the Way

I promise! Today (on set.... shhhhhh) I read all the American Cinematographer issues from 1940. Most was dribble, as the articles back then were aimed at either super technical or complete amateur.... nothing like it is now.

However there was an interesting invention that was supposed to eliminate the clapper slate... obviously it didn't take. I'll post soon!


Nestor Almendros: Locusts, Peanut Shells, & Helicopters

From American Cinematographer, Photographing "Days of Heaven" by Nestor Almendros (June 1979)

When the plague of locusts descends on the fields of wheat, Terry's atmosphere of daring and essential simplicity made me suggest a simple technique that would allow us to maintain optimum image quality (without resorting to an optical), and allow us to obtain the maximum dramatic effect.

For our foreground, we used live locusts supplied to us by the Canadian Department of Agriculture, but for the wide panoramics, silhouetted tractors and blackened workers, we used a technique used in The Good Earth: running the camera in reverse and dropping peanut shells from helicopters.

When the film was projected forward the "locusts" would appear to be flying up. Of course, this meant everything had to act or perform in reverse, specifically the actors and the tractors.

Virtually everyone said "No, it will never work." But the few believers convinced them to let us try-- again, special thanks to Terry's daring. And when they saw the rushes, they were astounded.

Maryse Alberti: HMI's

From ICG Magazine, A Way With Words by Holly Willis (May 2000)

"One of the biggest challenges of the shot was lighting it, and somehow still keeping it dark and moody," she offers. "We lit it mainly from the outside with big lights-- 20Ks-- on a couple of Condors with very small lights inside." One of Alberti's visual quirks is to light night scenes with tungsten balanced lamps. "It looks more like nighttime. HMIs have this hard-edged, shiny white that I don't like for night, unless that's what you're looking for. But Joe Gould's Secret has a very strong feel of realism-- there is nothing surreal or fable-like or otherworldly, so the lighting was designed to be real. The biggest lights we had were a couple of 20ks and Nightlights. For the rest, we just went with the range of a regular tungsten package."

Oliver Wood: Water, Water, and More Water.

From ICG Magazine, Watership Down by Pauline Rogers (May 2000)

Compressed Nitrogen:
"The set piece was hung over an area with a drain," says Wood. "We would pour water into the set-- and I mean pour-- and shoot. The water would then be drained away and we would go again. To protect the fronts of the lenses, we used Nitrogen air blowers like the ones we used on Face/Off. These blowers were so effective, we could literally walk the cameras through a wall of water-- moving with the actors, to get the intensity of the action."

Mag change!
Off the island of Malta, production constructed a 100 percent scale duplicate of a U-boat, weighing in at some 600 tons. Additionally, two full sized, tops of subs were floated in giant water tanks. "These were two 220-foot long 'subs,' surrounded by gigantic towers that poured salt water rain on the action all the time," confirms Wood. ... "The cameras had to be completely covered in plastic. That meant it took about 15 minutes to change the 400-foot mags. Although well-protected, the cameras kept breaking down from the abuse."

Peter Donan on the miniatures:
"When doing underwater shooting, the miniatures were shot using available light, as we were working about 15 to 20 feet underwater," describes Donan. "In order to control the quality of the light on these boats, we had silks made that were almost 180-feet long by 150-feet wide. They were created out of sailboat spinnaker cloth. We used this material because of its superior resistance to UV [light] and saltwater... At one point, we even had to paint the tank's bottom black to cut down on bounce reflection. That way, we could get additional shape from the hull and prevent it from looking too lit."

Oliver Wood: Flashlights and Sparks

From ICG Magazine, Watership Down by Pauline Rogers (May 2000)

As the American sailors make the perilous voyage home, the captured U-boat gets rocked by explosive depth charges, which knock out its power source and plunge its innards into darkness. Here, the cinematographer did his best to exploit the limited throw of a portable, practical source. "We faced the challenge of lighting so the audience could see, but not so that we interfered with the reality of the situation. So we lit the rest of the picture with flashlights," declares Wood. "It became a progression of lights breaking down as the sub got more and more water inside-- that made the shots darker and darker. For a while, we could use 'sparks'-- created by special effects-- to illuminate some of the shots. We would cue the lights or sparks by punctuation in the dialogue.

Oliver Wood: Black Wrap Submarine

From ICG Magazine, Watership Down by Pauline Rogers (May 2000)

All submarine interiors-- both American S-boats and German U-boats-- were photographed on sets constructed on Soundstage Five at the reputed Cinecitta studios in Rome, Italy. "We divided the first-unit shots up into sections," divulges Wood. "We had a sub on set at Cinecitta, created 20 percent bigger than normal size, which didn't feel any bigger, since we still had to stoop to get through the doors. Because it was going to be filled with water most of the time, we had to go 110-volt DC [in terms of electricity]. To light it, we cut hundreds of holes over the top to focus tiny little [150-watt] Pepper lights inside. The biggest light on this set was a 300-watt bulb. There was nowhere to hang the lights.

"We took the studs out of some of the loud speakers and put magnets in, so we could stick the lights to the metal. That worked fine, when we were level. However, when the set 'shook' they would fall out. So we tried finding ways to screw things in. Whenever we saw a light in the frame, we struck a bit of black in front of it. Simple, but it worked. I really think this picture was made with Black Wrap. It was an integral part of lighting this whole project!"

Oliver Wood: Anamorphic Close Focus

From ICG Magazine, Watership Down by Pauline Rogers (May 2000)

With most of U-571 planned for two cameras-- handheld, with occasional use of Steadicam-- Wood opted for Cooke S4 lenses and Arri cameras...

... Although known as an ardent supporter of filming features in the anamorphic format, Wood quickly realized that Super 35 would better serve this waterbound picture. "It was logical," he proclaims. "When it says 'close focus' in anamorphic you are usually at two or three feet-- try that in a submarine. We needed the one-foot distance for the confinements of the subs."


Conrad Hall: Making it Rain

From ICG Magazine, Smells Like Suburban Spirit by David Geffner (May 2000)

... As if returning full circle to the shadowy imagery of In Cold Blood, Hall utilized shadowplay through various set windows for the movie's waterlogged final act. "I had rain boxes built," the cinematographer declares, "which were approximately eight inches thick by four feet-by-four feet. They look like big fishtanks and each one sits on an easel at an angle, with a rain bar at the top to drive water down the Plexiglas surface. You can shine a light through each rainbox, and control sharpness and focus according to how the light is positioned and what type of intensity light is used."

Hall got innovative with the rain in one of the climax's key dramatic moments. Angela has just run from her best friend's bedroom, despairing at the truths hurled at her by Jane and Ricky. As the teary-eyed girl curls up on the stairwell, Hall introduces softly lit shadows of the rain outside as texture on the balustrade and walls behind her. It's a sad, yet ominous moment, and a prelude to the pending tragedy as Lester finds the distraught girl in the rainy darkness of his own living room.

..."We were all on the same page as to how long this driving rain would go on and exactly where in the film it would start. Obviously, my challenge is to make sure it's raining in every single shot- interior or exterior. The rain allowed for great stylization with lighting and composition. I could place shadows of the rain on people's faces, or behind them on walls and such in every scene. The effect was a build-up of tension and drama-- it can't rain that long without all the animals eventually getting aboard the Ark!"

Conrad Hall: Rose Pedal Wrangler

From ICG Magazine, Smells Like Suburban Spirit by David Geffner (May 2000)

Wild Roses and Gothic Guises

Nearly all of the special effects were executed in-camera, except a potent, computerized image of roses bursting from the teenaged bosom of Angela Hayes (Mena Suvari). Most of the truly provocative floral images occur during Lester Burnham's fantasy sequences. One mesmerizing shot featured roses tumbling down onto actor Kevin Spacey, who is gazing up from his bed at the object of his forbidden desire. As shot, actress Suvari lies on the floor amidst a bed of roses- some real, some artificial- with the forced perspective walls rising up on each side to camera. "We dropped roses from above and reversed the footage," Hall notes. "I was up behind the lens with a small paint bucket filled with rose pedals. My AC [Clyde E. Bryan] was sitting on the crane next to me, with a bucket of rose pedals as well. We had a Condor to the right and one to the left of camera, and the prop folks had large garbage bags filled to the top with rose pedals. Because it was a fixed camera, I had both hands free to drop pedals above and below the lens so the flowers would land right on Kevin. We used something like 250,000 rose pedals for that effect."

Conrad Hall, Sam Mendes, and...Tom Cruise?!

From ICG Magazine, Smells Like Suburban Spirit by David Geffner (May 2000)

Hall was initially reticent to tackle the dark subject matter in American Beauty (actor Tom Cruise actually recommended him to director Sam Mendes). But, in retrospect, the 70-something cinematographer seems like the perfect creative fit.


I Am Back

I am back. This means the glory of W.I.L.T, has returned. I read, discuss, and discover new things about cinematography everyday. Most of it, I consider incredibly interesting. Everyday I will share one of those things, maybe more if I have time.