AT THE fall Meeting of our Society, held at Lake Placid, it was my pleasure to outline the progress made in the use of tungsten filament globes in motion picture production up to that time. Since that date, largely due to the co-operation of the American Society of Cinematographers, The Academy of Motion Picture Arts and Sciences, and the Motion Picture Producers Association, unusual progress has been made toward solving the many problems which this form of lighting has presented.
A year ago the shortage of equipment for use with the tungsten lamps had not permitted us to use mazda lighting in a large way. The remarkable work done in close up photography, however, with

this form of lighting in conjunction with panchromatic film stock was so encouraging that equipment manufacturers put their attention on the designing of proper units for globe lamps. We now have available much satisfactory equipment.
During the past six months the attention of motion picture producers has been focused on establishing economies in their in their branch of the business. Actual experience in the production of numerous pictures, which have been made almost entirely with incandescent lighting has demonstrated that not only could the electrical cost factor be reduced, but that the new lighting made possible even better photographic results.

FIG. 2. Single Broadside.

You will doubtless be interested to note some of the features that make mazda lighting more economical. May I call your attention to a tabulation (Fig. 1) which shows the original cost of equipment for a typical operating unit using mazda lighting, in comparison with the equipment of the same unit operating with arcs? This tabulation is not theoretical, but was obtained from an actual operating condition, and shows an equipment cost very much in favor of the mazda units.
In current consumption, the incandescent equipment is unquestionably the more economical. Conservative estimates based

Fig 3. Double Broadside.

on studio experience set the current cost at 30% to 40% of that used by arcs required to do equivalent work. At present, because the mazda units do not require close operator attention, there is a tendency to keep units burning much longer than is required for actually shooting the picture. When this non-productive lighting, is taken into consideration, the current economy is even more in favor of the filament lamps.
Another very important factor in motion picture making, is the electrical labor. Mazda equipment is lighter in weight, simpler to line up and requires far less operator attention than does, arc equipment. Numerous checkings and comparisons demonstrate that the electrical labor costs are approximately 50% less where this lighting is utilized.
The cost of lamp renewals as compared with carbon costs is another case in favor of the incandescent system of lighting. Exact figures are lacking, but careful estimates leave a wide margin in

FIG. 4. Low Broadside.

favor of the "Inkies." As further improvements are made and the proper adaptations of lamps are worked out, it is expected that 1 1w comparison will show a still greater economy in this regard.
A year ago cinematographers and men in other technical branches of the industry were well aware of the excellent photographic advantages gained by the use of the panchromatic film stock when tungsten filament lamps were used as a light source. The efforts of cameramen and directors were limited by the lack of equipment units with which to operate. During this past year considerable attention has given to this matter of designing and producing satisfactory studio lighting equipment for utilizing the value inherent in the globe lamps. The rapid rise in the use of Mazda lamps has been largely due to the fact that satisfactory equipment has now been developed.

FIG. 5. Hi-Lo, Broadside.

The first demand in the way of equipment was for a lamp to be used in much the same manner that the twin broadside arcs were used with the arc system of illumination. To meet this demand an Incandescent Broadside was designed and built in both one-bulb (F1g.2) and two-bulb types (Fig. 3). These broadsides are applicable to the same work that was previously done with twin are broadsides in general set lighting, and when taking "close-ups." They have particular advantages in the excellent diffuse quality of light they render.
It was found by experience that the incandescent broadsides had to be supplemented with units placed near the floor to light

FIG. 6. Bunchlight

the lower portion of the figures in close-ups. To meet this need a low type (Fig. 4) and also a "Hi-Low" lamp having two hoods, (Fig. 5) was supplied.
In these first units both the 1000-watt T-20 and the 1000-watt PS-52 lamps have been the light source. At present the PS 52 lamps are more favored due, in the main, to their longer life and less initial cost.
Another unit for general lighting was developed which utilizes the light from four lamps of either 1000 or 2000 watts each (Fig. 6). These globes are mounted in an aluminum housing giving a wide angle of reflection and are especially suited for foreground lighting.

FIG. 7. Floor Strip Lamp

For use in lighting doorways, windows, recesses, and back of columns, units were constructed consisting of strips of several PS-52, 1000-watt lamps and having adjustable wing reflectors. (Fig. 7).
A highly efficient lamp has recently been developed which consists of a heat resisting glass reflector, capable of producing a soft projected light. This equipment is used in conjunction with the PS-52 lamps of various wattages (Fig. 8) and is useful when it is desired to project general lighting into deep sets. It also has valuable properties for modeling the subject in close-ups.
For general overhead lighting, several units have been worked out. Fig. 9 shows a 5 lamp overhead strip which can be adjusted to various angles.

FIG. 8 Rifled Reflector Lamp

These overhead strip lamps may be grouped either side by side, or end to end, making possible great flexibility in the light distribution. This unit was built to use the 1000-watt PS-52 type of Mazda bulb.
For modeling purposes, back-lighting, and effects, several types of projectors which give concentrated beams have been developed.
Fig. 10 shows a 1000-watt, condenser spot, utilizing a G-40 Mazda globe in conjunction with a spherical mirror and a plano-convex condenser.

FIG. 9. Overhead Strip Lamp.

FIG. 10. 1000-watt Studio Spot

A lamp somewhat similar in design has also been made to take a 2000-watt G-48 Mazda bulb. These lamps are particularly adapted to subject lighting in the close-ups, to back lighting from either the floor or from the parallels, and for spotting out objects on which it is desired to center attention.
Mirrored projectors have very definitely proved their value in tungsten lighting. The efficiency of their reflecting surfaces and their ability to collect a maximum angle of light promote high efficiency. In this type of unit there are the 18 inch Sun Spot (Fig. 11) and the 24 inch Sun Spot which use respectively the 2000-watt and 5000-watt globes.

FIG. 11. Eighteen-inch Sun Spot.

These units find their utility purposes similar to that for which the 80 and 100 ampere Rotary Arc Spots have been used; that is, in back and cross lighting from the top of the sets, and effect lighting through openings.
For photography which demands strong shafts of having high intensity, in producing sun effects through windows and archways, and for very deep general lighting, the 24 inch and 36 inch Sun Spots are equipped with the 10,000-watt Mazda globes. In this field of lighting they have proved invaluable. These units are supplied with parabolic mirrors of standard make, but of a focus best adapted to meet their special requirements.
The incandescent Sun Spots offer a great advantage over arc equipment of similar type due to their light weight, which is only made possible by the use of Mazda lamps as a light source instead of the heavy, complicated, high intensity arc mechanism.

FIG. 12. Equipment distribution for close-up.

Having presented the different equipment units which are now available for tungsten lighting in motion picture production, it will no doubt be of interest to present some photographs of actual sets illuminated with the various types of equipment.
Fig 12 shows the use of tungsten lamp equipment in making a close-up.
The distribution of equipment on a medium sized set is well illustrated by Fig. 13. In this case 18 inch Sun Spots furnished the back and cross light from the top of the set. A five unit overhead strip is used in the top center, and broadsides give the floor and foreground illumination.
Another interesting line up is shown in Fig. 14 which illustrates an arrangement of top and cross lighting. This is part of a set representing a hotel lobby. It was rigged for a long shot, approximately 100 feet in depth. The camera angle embraced a height of about 20 feet.

FIG. 13. Distribution of equipment on medium size set.

Eighteen and 24 inch Sun Spots were the principal units used. The Sun Spots were equipped with 2000-watt and 5000-watt lamps. Bunch lights and some Cooper Hewitt banks were also used for the general overhead lights.
The photographing of the interior of a Zeppelin presented quite a problem in illumination. Fig. 15 depicts a shot in a current production in which extensive use is being made of Mazda lamps

FIG. 14. Top and cross lighting arrangement.

FIG. 15. A Typical Set-up.

and illustrates the use of various types of equipment. On the floor are broadsides, floor strips, and sun spots. Conditions were such that no top light could be used, so the cross lighting was furnished by several 18 inch Sun Spots. The hard shadows, however, were produced by the light from a 24 inch High Intensity Arc Sun.
While the results so far obtained with tungsten lighting have been most satisfactory, there are still many problems to be solved. We have been fortunate, in attempting to solve the problem of making motion pictures with tungsten filament lighting, to have had the hearty co-operation of the various interested groups. The film manufacturers and the laboratory specialists have made excellent strides in the perfection of suitable film stock and in its subsequent handling in the laboratories. Their assistance, by generously donating film for experimental photography and in developing the exposed stock, has been invaluable. The lamp manufacturers have sent us their specialists in illumination and lamp production, and are putting forth their efforts to give us globes best suited to our various needs. The cinematographers of the industry have spent many hours in making test shots and by their work we have obtained much information essential in equipment design. The illuminating engineers in the studios have suggested many ideas in the interest of perfecting the various equipment units. The producers' organization has furnished actors and technical men and generously financed the experimental work in this development period. With all these various groups working in harmony, we believe a firm basis has been set for an approach to that ultimate but never attained goal of perfection.

DISCUSSION

MR. BUTTOLPH: Relative to this Cost Comparison, as a matter of scientific record I think we should be given a more detailed statement as to how the cost figures were arrived at.
MR. MOLE: These figures were arrived at by asking various studios for cost data from productions already made.
MR. PALMER: Does the cost value include renewal cost of the incandescent lamps used?
MR. MOLE: Yes. We have no data on lamps above 5,000 watts, but productions were made with 5000-watt lamps, and the renewal cost was slightly lower than carbon replacement cost during a similar production.
MR. ROSS: Why were the cable connections lighter than those of the arc lights?
MR. MOLE: On the broadside unit, we used two 1000-watt lamps and consumed 18 amperes, whereas our arc broadside used 35 amperes. The arc uses a No. 8 two-conductor cable, whereas the incandescents use No. 12.
MR. ROSS: Are the cables which are used in the studios armored?
MR. MOLE: No. The most durable up to the present are of two types: a rubber covered cable; and the other is a cloth covered cable.
MR. PALMER: With regard to the voltage conditions under which these lamps are operated, is it the custom to operate the lamps at their normal rate of voltage, as printed on the lamps, or at a higher voltage?
MR. MOLE: They try to operate them at the rated voltage. No attempt is made to operate them at a higher voltage, but I should say from experience that lamps are operated at under rather than normal or higher voltage.
MR. GRIFFITH: Your statement would lead me to believe that the tendency was towards the use of better optical systems in the lamp units with perhaps rippled reflectors as in your "rifled" unit.
MR. MOLE: That is the general tendency. The reason for making the single and double broadsides was that we had to make a unit which was counterpart of the old arc reflector. The cameraman complained that he could not control them, so we had to give him one which has a definite cut-off line in the horizontal and vertical position.
MR. GRIFFITH: When they learn how to use the more efficient unit properly, will it not result in greatly improved lighting as compared with the present "hit-or-miss" lighting from the so-called "broadside?"
MR. MOLE: Yes; fewer and more efficient units will be used. We may have gone to an extreme in the minimum of equipment that is used. We will probably find in the future that the amount of light on sets in current value will increase.
MR. ROSS: Referring to the rifled reflector type of broadside, it is often necessary to employ baffles which are readily attached to the rectangular housing of the arc broadsides. What provision has been made for their use on the round type or incandescent broadsides?
MR. MOLE: Where you have the baffle, that type of is generally used in close-ups, whereas the "rifle" is not used for that purpose but for more general illumination where you want to penetrate into deep recesses. Adaptations can be made for cutting off the light where it is not wanted. It will not entirely replace the broadside; that is, the percentage will be about a third, where they now use twenty broadsides today, they may get down to about six.
MR. PORTER: Mr. Mole showed a slide which illustrated one point very well. Your may recall the picture of the dome with the tubular lamps around it. This is very typical of the cause of a great deal of complaint on the life of incandescent lamps, particularly when their use first started. It is no fault of the lamp but a case of misuse. Where the lamp designed with long vertical coils is burned horizontally, the filament will not stand up in that position. They sag when hot. That lamp is designed for short life-for projection service, where high screen brilliancy is more important than long life. There is no question that as incandescent lighting continues in the studio, those things will disappear, and now that we understand better what the limitations of the lamps are, lamps are being designed for particular studio conditions. They are likely to be used in horizontal position, tip down or up, and the studio work is so rapid that you can't expect the studio electricians to burn the lamps in one particular position or another. They must burn in any position. That is one of the things Mr. Mole referred to when he said the incandescent lamp manufacturers were designing lamps more suited to studio conditions.

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