Movie Makers (Jan-May 1928)

filmed. The prism reflects the image at right angles to a ground-glass, where it is viewed under magnification through the adjustable eye piece (M). Accurately controlled focusing thereby becomes possible. The device operates similarly to a reflex camera, in which the mirror is replaced by the small prism. Fig. 5 shows the lens and reflex focuser attached to the camera. Critically sharp focus may be obtained by viewing the object through the eye piece M, which eliminates all guesswork in focusing, and at the same time assures the object being correctly centered on the film. However, should it be necessary to pam the camera to follow a moving object, this can be readily done through the view finder in the usual way, after the object has once been focused. The reflex focuser is also supplied with extension tubes measuring %, 1 and l1-) inches, etc. These serve to increase the extension of the lens in accordance with the increase of effective focal length, up to 8 inches and thus give a range of focus from infinity up to within 8 inches of the diaphragm. F&6 O Fig. 6 shows the reflex focuser equipped with two of the extension tubes N and 0, and the camera attached to the tripod by a ball-and socket head so as to point in a downward direction, as would be used in photographing small insects or other objects on the ground. The writer has obtained some excellent results with this device in photographing ants, spiders, caterpillars and other small insects under conditions which would have been impossible with the ordinary telephoto lenses. There is no difficulty whatever in obtaining objects in sharp focus even when located as close as 8 inches to the lens diaphragm. Table 5 shows the horizontal and vertical distances covered by a picture using a 4-in. lens at various ranges from infinity to 8 inches. Area Covtrei fcg ^Ectur-e -4--L***. "CKltawtt a£ Cty«i x4o**Cy i*x-oX VttiCcot £«,«. 1)C»13cmjt (*) "EUU TVeU ee U^> +o oo 11^ +0 00 looo B Ion. izra 73oo ft So B Sov& 3-ti» 30 S S.03S 2-I7& 20 & *.oi a I-44S 15" » |.s»e l«7& IJSt 1+.4 « /0.3 a lot' Mia asa SB 14'" fc7* 7* 8-/B!! FS5* 4" l-ISS Ton je Sf^a. 41 H 45 4-j-is S-aS 3'/te s-iSra UU 3feS 5*7 a SW*B 3o* Ml a l-70fi 24* 2-04' l-44'i ' Igfi 1.43 IS i-oa a IS.2! 0-8I5U . o-res-a II a o-fise on a io e O.tl'1 0.435 a am osjis o-3«Ji 8a 0408?^ 0. 202o'i(t) xr) tor Qh-uds *£,&«. t\* doA^vin, , TA-. Xiifru*ec (f) l?«^>Tcsc*Ct Ortvo-U dUM*ci*inhii of. £&*+ t«f rf«4 } q+Jl q£ tVJ eListfr.*c« o"btf£h, <^u. ~rty-n&"-uJ "Ufie Svjjl. TABLE 5 In close-up work of this kind it should be borne in mind that the diaphragm markings are altered as the focal distance of the lens is increased. The "stops" as engraved on the lens are only strictly correct when the lens is focused at infinity. They represent in each case the equivalent focal length of the lens divided by the diameter of the diaphragm aperture. As the focal distance is increased, it follows that the correct Corrtdruvl ot Sto-pS Km. CLost5a^.^e W^UC otop -MarK.«~uj? oit i tus F-4-s P5-E F to | F8 F II Pit. 41N F45 FffS" Ffc-3 . F8 Fll Fit 4H FF-i Fl-2. F7-2 I F.) FOA F 18 r F*4 *H F8 : Flo FI3J7 F2o Si. F<!> til F8& i Fll F IK| F2* L F t 8 P8-3 FU ! FI2. Fll-S f24^ t'i P7-3 F1 | Fio-4 i FI3 FI7.<) Fit 1 F1-] F*t FlU i F14 Fll-S 1^28 Ik F&4 Flo-3 FIX FMS P3fe F3o 8 M F II F1H Flfc F2*. *31 Get the Most Fun from your Home Movie Projector There's Adventure . . . Comedy . . . Drama in Kodak Cinegraphs MOVIES of famous explorations into the four corners of the world. Gripping . . . educating. Hollywood's renowned comedians in side-splitting snatches of their funniest pictures. Moviedom's star actors and actresses at their best. All the very latest Cinegraph releases are here for you to flash on the screen with your i6m/m projector. There's a wide variety to choose from. Come in today and make your selections. Write for our list of the most recent Cinegraph releases. Headquarters for Home Movie Equipment Eastman Kodak Stores, Inc. Madison at 45th St. New York City TABLE 6 HUMIDIFYING SOLUTION for Motion Picture Films This solution will keep your films flexible and in good condition continu' ally if applied occasionally to the pad in the humidor can. Dry and brittle films may be softened by moistening the pad and allowing them to remain a day or so in the closed can. Send $1.00 for a 4 pz. bottle {Dealers write for prices) STANLEY A. TOMPKINS 350 Madison Avenve New York City F if t y -f iv e