Motion Picture News (Sept-Oct 1918)

2426 (Equipment Service) Motion Picture News i»nMiiinm»mmimmmmiimnmTniininuiiiiii! lmiiimiiiinrimirninninirTmniiuimMinnnmiiimnntimianiliniimnilllimilinirillllillllllilllllllli^ | 1 The Essential Requirements for Improved Projection j are SPEER CARBONS SPEER Alterno Combinations for A.C. Work and SPEER Hold-Ark Combinations for D.C. Work Produce Incomparable Results Write today for descriptive folders. Read the unbiased opinions of operators Place an order now with your Supply House "The Carbons with a Guarantee** Manufactured by SPEER CARBON COMPANY ST. MARYS, PA. "lllimnmiimnimimimniiimmiiiiiiii nnnniiiiiiiimmmmnmnimimnmiimiimiimimiiTm^ GOERZ Goerz Kino Hypar F:3.5 Improvement is the constant aim of motion-picture producers. Scenes and effects must be well-nigh perfect. To accomplish such effects we recommend the GOERZ KINO HYPAR F :3.5 lens. It is made in 1%, 2, 2% and 3 inch focal lengths and may be fitted to nearly all standard equipments. Used with the well-known GOERZ VIGNETTING DEVICES it leaves nothing to be desired. Write now or call for our latest descriptive matter. C. P. GOERZ AMERICAN OPTICAL COMPANY East Thirty-fourth Street, New York City RadiO X^Mat-slide % PATENT APPLIED FOR If) M M 'LEND— THE •' i WAY THEY FIGHT o A Good soldier doesn't fcj let the thought of yester as day's battle make him forget today's. Never mind the Liberty W ' Bonds you bought before. o The 4th Liberty Loan is 1 as NOW! BUY BONDS i TODAY! i L J • For Sale by all Leading Dealers RADIO SLIDES CAN BE WRITTEN ON A TYPEWRITER LIKE A LETTER $1.75 Box of 50 For Sale by All Leading Dealers Accept no substitute— samples free War Newt, Liberty Loan Announcements, Coming Attractions, Election Returns. RADIO MAT-SLIDE CO. }&&$5£ffi& Mazda Incandescent Electric Lamps for Projection Service FOR several years development has been proceeding to adapt the Mazda incandescent electric lamp to motion picture projection. . This work has involved exhaustive studies of light source dimensions, optical systems and lamp performances. It has now reached a point where the incandescent lamp manufacturers announce a complete line of lamps for projection service. Of these the one which will deliver the most light to the motion picture screen is the 900 watt, 30 volt, 30 ampere Mazda C lamp. This lamp is in the T-20 tubular bulb, 2y2" in diameter, 10" overall length, with a light center length of 4*4", and is fitted with the mogul screw base. It must be used with its own mirror and condensing lens system, the latter part of which has been recently developed, and will then give staisfactory service for throws up to 100 feet on a 12 x 16 screen with prepared or reflecting surface when the current consumption of the arc replaced does not exceed 60 amperes A.C. or 30 amperes D.C. The next smaller amount of light is delivered by the 600 watt, 30 volt, 20 ampere lamp, which must also be used with its own mirror and condensing lens, and which finds its application where there are shorter throws and smaller screens, such as are used in churches, lodges and other places where less amount of light than that given by the 900 watt lamp is adequate. This lamp will find its major or principal use on country home lighting outfits and elsewhere where the power supply is limited. The lamp is made in the T-20 bulb, having the same overall dimensions and same light center length and base as the 900 watt lamp. For other special services, such as portable projectors, stereopticons, spot lights, etc., additional Mazda C lamps in tubular bulbs have been standardized, giving a complete line of lamps in tubular bulb, as listed below. Mazda C Lamps in Tubular Bulbs for Stereopticon and Projection Service. Light Center Volts Watts Bulb Base Length 6 72 T-10 Med. Screw 3*6 6 108 T-10 Med. Screw 3*6 12 72 T-10 Med. Screw 3*6 12 108 T-10 Med. Screw 3*6 28-30 300 T-16 Med. Screw 3*6 28-30 *600 T-20 Mog. Screw 4*4 28-30 **900 T-20 Mog. Screw 4*4 110-125 300 T-16 Med. Screw 3*6 110-125 600 T-20 Mog. Screw 4*4 110-125 1000 T-20 Mog. Screw 4*4 **This 900 watt Mazda C lamp is recommended in all cases for general motion picture theatre service. *This 600 watt Mazda C lamp is recommended for short throws and small screens such as found in churches, lodges, etc., where a less amount of light than that given by the 900 watt lamp is adequate, and for use on country home lighting outfits where the power supply is limited. It is not recommended for general motion picture theatre service. October 1, 1918. Operators' Inquiries H. C. Young, Pittsfield, Mass., inquiries " From the head of my machine to the screen is a distance of 82 feet and my screen picture is 18 feet 3 inches by 14 feet. What size condensers do I need? " Reply: Although the correspondent, like many others, has failed to furnish complete data, we assume from the measurements given that his projection objective is of 4 inches equivalent focus. We would therefore advise a 6^/2 inch and a 7l/2 inch condenser combination. If the condensers are of good quality and if the combination is properly focused, i.e., at the correct distance from the aperture, a suitable screen illumination should be obtained if other things are right. Chas. H. Gresty, Blackwell, Okla., inquires: "What is a satisfactory recipe for making film cement? I make my own by dissolving 3 inches of plain film in one ounce of accytic ether. Do you approve of this?" Reply: We do not approve of such a mixture, but v. \H Jpo e the following recipe. It is : equal parts of collpdior., sulphuric ether, amyl acetate, accytic ether. Be sure to mention " MOTION PICTURE NEWS " when writing to advertisers