Sekonic L-398M manuel d'utilisation

SEKONIC STUDIO DELUXE II L-398M Operating Instructions[...]

Features ........................................................................................................ 2 Specifications ................................................................................................ 4 Part Designations ......................................................................................... 5 Accessorie[...]

Nearly all photographic subjects combine complex variations of strongly reflecting surfaces (high reflectivity) and weakly reflecting surfaces (low reflectivity). These variations delicately influence exposure determination and to which portion the expos ure is set becomes a vital factor that considerably affects the appearance of the finished phot[...]

7. After combining film sensitivity and shutter speed, direct reading slides (optional) can be used for directly determining the aperture value. 8. Selenium photocell is employed as light sensing element, eliminating need for battery. 9. Wide selection o f available accessories allows numerous photo graphic techniques to be enjoyed. 3[...]

Measuring System Incident light (reflected light system also capable) Measuring Range At ISO 100, EV 4 - 1 7 Measuring Accuracy Within ± 0.3 EV (1/3f stop) ISO Scale 6 - 12000 Shutter Scale 60 - 1 /8000 second Aperture Scale 0.7 - 128 Cine Scale 8 fps - 128 fps EV Scale 1 20 (exposure value) Calibration Constant C = 340 K = 1 2.5 Dimensions 112 x [...]

PART DESIGNATIONS Fror’ pointer xopper button mat Lumlsphera Light sensorm 1 Footcandle scale ,;nrirlan+ linb.+ P Aperture value -1 (for direct reading) @ ___ ---. - w , wne scale 44 I - A -__...“^ ^^^I^ /- Rear 5 Meter scale Dial scale[...]

Lumisphere Lumidisc Lumigrid Total of 11 direct reading slides (set of 11 slides in case). e; Optional Accessories (sold separately). Direct reading slides. High (H) slide[...]

1. Stopper Button Operation If the stopper button is press - ed when the stopper button mark is set to the meter needle deflects according to bright - ness. Then when the button is released, the needle remains fixed at the indicated p osition. By holding the stopper button depressed and turning it clockwise so that the mark position becomes the nee[...]

Inc ident Light Measurement 8 1. Lumisphere a. Mount Lumisphere sensor To white dots of Lumisphere frame and light sensor, then turn Lumisphere carefully clockwise to secure. b. Set film sensitivity knob to sensitivity value of employed film. Set ISO value to right side ISO mark Photo shows setting for ISO 100. c. From position where subject is to [...]

needle deflects according to brightness. When the stopper button is released, the meter needle becomes fixed at the deflected position. If the location is excessively bright and the meter needle deflects beyond scale, insert the High slid e e. Read the footcandle indication of the meter needle. f. Transfer footcandle value to the dial scale dial ri[...]

1 c'. g. At this time, the shutter speed scale and aperture scale combination becomes the correct exposure. Example: With High slide inserted, meter indicates 80 footcandles At ISO 100, the proper exposure becomes 1, 250 sec at F 5.6, 1; 30 sec at F!16 and 1 sec at F - 90. h. By changing ISO setting, the set combination of shutter speed and ap[...]

2. Lumidisc. Employ for illumination contrast Adjustment and luminance measurement. • Contrast measurement a. Mount Lumidisc sensor Install in the same manner as Lumisphere. b. Hold meter at subject position and point Lumidisc directly toward center of main light. c. Press stopper button read meter scale footcandle indication d. Turn the memo poi[...]

• Luminance (Lux) measurement a. Mount Lumidisc Lumisphere. to light sensor in the same manner as b. Place Lumidisc parallel with the measured surface. and read meter scale footcandle c. Press stopper button indication d. Multiply this value by 10.76 to obtain lux. Example: 80 x 10.76 = 860.8 lux If meter deflects beyond scale, insert High slide [...]

13 Reading this exposure value to perform setting becomes convenient for cameras which employ a light value system shutter and aperture combination. 1. Exposure Value (EV) number Readout Other Operations e. Press stopper button re ad meter scale footcandle and indication footcandles are units of incident light only, this value becomes simply a refe[...]

Note: Standard theatrical cine film speed is 24 fps at 1/50 sec. This position is indicated by a red line on the scale. 14 Note: Some cine cameras possess faster exposure times due to a narrower rotating shutter angle (angl e of light transmitting portion). It is important to know the accurate film speed versus shutter angle value for your camera i[...]

3. Using Exposure Multipliers ( - 2, - 1, +1, +2) Exposure multiplier indications are provided at both sides of the marks of the dial scale. Use the - 1 or - 2 mark when desir ing to cut the exposure to 1!2 of 1!4 and +1 or +2 mark to multiply the exposure by 2 or 4. Set the appropriate mark, instead of the or, to the dial scale value. EMPLOYING SP[...]

Note: One set of slides consists of slide numbers 1 - 11 in a case. The High slide can also be used as a direct reading slide. 2. Direct Reading Slide Application When photographing, select slide from the above table according to film sensitivity and shutter speed. Insert slide and perform measure ment in the same manner as for incident light. Read[...]

MEASUREMENT EXAMPLES WITH VARIOUS SUBJECTS 1. Portrait Photography There are various kinds of human subject photography. In a case, for example, of a skier against a snowy mountain background, the human subject simply becomes a picture detail and for t he purpose of determining the exposure, this cannot be considered portrait photography. In the fi[...]

2. Typical Scenery In the case of scenery, measure by using the Lumisphere at the camera position (refer to section on Incident Light Measurement). Although the previously described standard holding method is adequate, if lighting conditions of subject a nd camera positions are dissimilar, move the meter to a position where conditions are the same [...]

Distant scenes are subject to haze due to atmospheric effects on light and can be easily overexposed. For this reason, first use the Lumisphere and measure by standard method from the camera position. Then point the Lumisphere toward the s un and measure. Determine exposure from the mean of the two obtained values. Note: To obtain the mean of the t[...]

4. Snow Scenes a. Many cases of problems occur with reflected light measuring methods due to snow surface glare. Using incident light measurement eliminates these concerns. Freshly fallen snow possesses a reflectivity of approximately 73%, wh ile even after several days in urban areas, this declines only to about 60%. Compensation must therefore be[...]

0Note 3: In situations with direct or top lighting (sun near zenith), the Lumisphere will detect reflected light from the snow surface. Some means of blocking the light from below becomes required in this case. b. In some cases, good results can be o btained with reflected light measurement under back light conditions, cloudy snow scenes where glar[...]

In typical cases of back and side lighting, although the surface of a 3 - dimensional subject facing the camera becomes dark, a portion is usually strongly lighted. Even though standard measurement with the Lumisphere can bring out detail of the darker p ortions, on occasion, the brighter portions can become overexposed and difficult to see. In som[...]

APPLICATIONS SUMMAR Y 1. Special Features of the Studio Deluxe 11 As the Studio Deluxe ll is a high precision measuring instrument, by fully utilizing its capabilities, its special functions can be displayed covering an additionally wide range of applicati ons. Incident light measurement is an extremely practical method in actual photographic situa[...]

2. Illumination Contrast Light balance measurements are the most important application of the Lumidisc. This consists of measuring the ratio of main light and fill in light in order to perform vital adjustments when photographing an illuminated subject. Th e photographer is advised to record the data obtained for his particular equipment. This will[...]

Main light measurement Fill in light measurement Use white or silver reflector to brighten shadow portions of subject. Exposure measurement 25[...]

Illumination ratio can be varied by keeping the main light fixed and varying the fill in light. Reflected Light Measurement Reflected light measurement is employed for the following purposes. a. Luminance range adjustment. b. Self - lighted subjects such a s neon signs which can only be measured by reflected light method and locations such as show [...]

Shown here is an example of using Lumisphere and by normal measuring method without slide, meter needle indicates 640 foot candles. With film sensitivity of ISO 100, exposure becomes f 45 and shutter speed 1 second. mark at this time indicates 20 . This 20 indicates the exact center point of the luminance range. In the same condition, install Lumig[...]

b. Hold meter about 15cm from the subject, point Lumigrid to each surface of the subject and read the footcandle scale value. c. To determine the luminance range, it is sufficient to divide the highest meter indication by the lowest. For example, if the highest value is 80 and the lowest 5, the luminance range becomes 80/5 = 16/1 or 16 : 1. Luminan[...]

The Studio Deluxe indicates normal color photograph lumi nance range limits corresponding to 2 f stops left and right of the luminance range center point. 4. Illumination Adjustment The Studio Deluxe possesses an array of functions for the per formanc e of illumination adjustments which were nearly unknown in earlier instruments. It allows the shoo[...]

examples to provide full control over movie scenes. It would not be erroneous to also apply these to still photos. Stage 1 Determine overall lighting strength. a. Set meter to ISO 100 (see film sensitivity intermediate values). b. Set 24 red line of cine speed scale to F/5.6. c. At this time, lower than 640 (footcandles). If this is taken as the me[...]

Adjust luminance range a. Install Lumisphere. b. Hold meter at subject position, point Lumisphere toward camera and read needle indication. With all lights turned on, adjust main light so that indication becomes 500 footcandles. c. Set ark indicated value. This value becomes 16 to indicate luminance range center point. If by experience the required[...]

As can be noted from the above formula, if the subject luminance is fixed and the magnification changes, the film plane brightness (illumination) varies in the inverse proportion (M + 1) 2 . With a large subject distance, M is small and this effect becomes nearly absent, but as the subject distance decreases, M becomes larger. In an actual photogra[...]

Compensation factor = (M + 1) 2 Compression Enlargement . Subject to Compensation Subject to Compensation image ratio factor image ratio Factor 20 : 1 1.10 1 : 1 4 19 : 1 1.11 1 : 1.25 5 18 : 1 1.11 1 : 1.50 6 17 : 1 1.12 1 : 1.75 7.5 16 : 1 1.13 1 : 2 9 15 : 1 1.14 1 : 2.25 10.5 14 : 1 1.15 1 : 2.5 12 13 : 1 1.16 1 : 2.75 14 12 : 1 1.17 1 : 3 16 1[...]

HANDLING CAUTIONS Since the Studio Deluxe ll is a high precision instrument, use ample care in regard to the following points. Avoid dropping or subjecting it to strong shock. Do not store in high temperature or high humidity locations. Do not store in are as subject to magnetic fields or where insect repellants are located (metal cabinets, clothin[...]

SEKONIC CORPORATION 7 - 24 - 14, OIZUMI - GAKUEN - CHO, NERIMA - KU, TOKYO 178 - 8686, JAPAN TEL: (03) 3978 - 2335 FAX: (03) 3978 - 5229 T156270B - A[...]