Luna-pro sbc light meter, instruction manual, user manual, PDF manual, free manuals

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			Congratulations!
This Luna-Pro sbc Instruction Manual is more than just an instruction book - it is actually a short course in the creative use of an exposure meter.

			You now own the most advanced exposure meter, the heart of the Luna-Pro sbc System.
Section I offers "Basic Operating Instructions". To use your Luna-Pro sbc properly you need only read and follow the simple instructions in this section.
			The new Luna-Pro sbc System is the most flexible, versatile and adaptable photographic light measuring system ever devised, while at the same time being very simple to use. In order to get maximum benefit from the quality design and operating features of this precision instrument, please take a few minutes to read this instruction manual.
Section II, however, moves a step forward - to "Getting the Most Out Of Your Luna-Pro sbc. Here you can really find out how to put the unique versatility of your Luna-Pro sbc to work for you. 4www.butkus.org/chinon
Section III gives you "Helpful Hints" for special shootings - action, snow and sand, sunsets, night, and more - the type of information you need for that extra creativity.
			Your new Luna-Pro sbc utilizes the latest advances in silicon cell sensors and also high performance electronic circuitry including integrated circuits to provide fast, accurate, repeatable readings under the most difficult professional conditions.
And Section IV provides you with full details on the "Accessories" for your Luna-Pro sbc - to turn it into a true exposure system.
			The Luna-Pro sbc represents a most significant development by Gossen GmbH, Erlangen, West Germany, Europe's largest manufacturer of precision electrical instruments since 1919, and one of the outstanding pioneers in exposure meter design since 1932.
We sincerely hope that this manual will be of help to you and will answer most of your exposure measurement questions. If it does not, feel free to contact your BMC specialist dealer. In addition, our Consumer Service Department is available for help with special requests.

Table of Contents

	II. h. Zone Systems 21
Section I. Basic Operating Instructions 5
	II. I. Film Reciprocity Failure 22
I. a. Zeroing the Meter 5
	II. m. Intermediate f/stops 23 II. n. Intermediate Footcandle Values and Exposure Time
1. b. Inserting & Changing the Battery 5
1. c. Setting the Film Speed 6
1. d. Exposure Factor Scale 6
	Section III. Helpful Hints .: 24 III. a. Choosing Between Action Stopping
I.e. Making a Measurement 7
1. f. Reading the Scales 7
		Ability and Depth-of-Field 24
Section II.
	III. b. Snow & Sand 25
Getting the Most Out Of Your Luna-Pro 10
	III. c. Sunsets 25
II. a. Continuous or Stored Readings 10	III. d. Night Lighting 26
II. b. The Null Method of Measurement 11
	III. e. Backlighting 26
II. c. Exposure Correction Dial 12 II. d. Footcandle Readings with the Luna-Pro sbc 13
	III. f. Copying 27
	III. g. Excessive Skylight 27

	III. h. Bellows (Extension) Factor 27
II. e. Carrying Case 14
	Section IV. Accessories 30
II. f. Methods of Measurement 14
II. g. Incident Measurement 16	Section V. Appendix 35
II. h. Reflected Measurement 17	Service 37
II. i. Scene Brightness Range 19	Specifications 38
11. j. Color Crossover 21	Additional Reference Material 39

Operating Parts & Scales
	1. Spherical Diffuser		CLICK ON IMAGE BELOW TO ENLARGE
	1. Spherical Diffuser
	2. Green Zero Check Point 3. Meter Needle
	4. Power Switch 4www.butkus.org/chinon
	5. Cine Scale
	6. Electronic Flash Reference Mark
	7. Battery Test Button 8. ASA Index Triangle 9. Film Speed Scale
10. Exposure Correction Dial
11. Computer Dial
12. Battery Test Zone
13. Exposure Correction Signal 14. Exposure Time Scale 15. Aperture Scale 16. Film Speed Setting Disk 17. Exposure Value Scale 18. Exposure Factor Scale Index Mark		19. Measuring Cell Window (under diffuser) 20. Zero Adjusting Screw 21. Table of Footcandle and Lux Values 22. Battery Compartment Lid

Basic Operating Instructions

The following instructions are a quick operating guide to the Luna-Pro sbc. For best results, also read the additional sections describing in more detail the different functions of the Luna-Pro sbc. 4www.butkus.org/chinon					I. b. Inserting & Changing the Battery`
					Your Luna-Pro sbc is supplied with a 9-volt battery which fits into the battery compartment at the bottom of the meter. Slide the battery compartment

I. a. Zeroing the Meter
I. a. Zeroing the Meter
With the battery removed, check to see that the meter needle (3) rests on the green zero check point (2). If not, turn the zero adjusting screw (20) until the needle rests on the zero mark. 4www.butkus.org/chinon
					lid (22) off and attach the battery to the battery clip inside. Note that the battery can only be connected one way. Insert the battery into the battery compartment and slide the lid back on. Check the battery by pushing and releasing the power switch (4) and then pushing in and holding the battery test switch (7). The meter needle should be well within the battery test zone (12).

I. e. Making a Measurement			Aim the meter at the subject for a reflected light reading or at the camera for an incident reading. Depress and release the power switch (4). Rotate the computer dial (11) until the meter needle is over the "0" null line. Read the desired combination of f/stops and shutter speeds on the computer scales.
Select the method of measurement desired, either reflected or incident. (For details on incident vs. reflected measurements, see section II. f. For reflected readings slide the spherical diffuser (1) to


			NOTE: When you release the power switch, the value measured at that moment will be automatically read, and electronically stored by the Luna-Pro sbc. To conserve battery life, the meter switches itself off automatically after one minute, and your measurement set on the computer dial remains for convenient and repeated reference. For continuous measurements, see page 10.
either side of the meter. For incident readings, slide the spherical diffuser in front of the measuring cell window (19) until it "snaps" into the detent.


			I. f. Reading the Scales

			The Luna-Pro sbc has six scales used to give you information on ASA index, aperture, shutter speed, cine speed, exposure value (EV), and exposure factor (EF). In addition, accessory clip-on scales are available for direct reading of other light measuring values such as footcandles.

The cine scale allows direct reading of apertures for various cine speeds (frames per second). These speeds correspond to actual exposure times on the exposure time scale only for cameras having standard shutter angles. For XL cameras or those with adjustable shutter angles, consult the camera's instruction book for the equivalent shutter speeds and read your exposure opposite that speed on the time scale. Also note that some reflex viewing movie cameras use beam splitters to provide a light path to the viewing screen. These beam splitters reduce the light intensity to the film plane, so that a correction factor must be applied to the indicated f/stop. Once determined, the correction can be programmed into the exposure correction dial. 4www.butkus.org/chinon


An EV (exposure value) scale (17) is provided for cameras with shutters calibrated in EV. The Luna-Pro sbc EV scale is calibrated from -8 to +24. Numerical values are shown for full EV values with intermediate values indicated by short lines at 1/3 EV intervals. Exposure values are used elsewhere on several scales which will be explained later. It is important to remember that a change of 1 EV is equivalent to a change of 1 f/stop. An EF (exposure factor) scale is included for making exposure corrections when using filters, bellows, extension tubes, etc. It is calibrated for exposure factors up to 64. Detailed information on this scale is in section II c

Section
Section			power switch. The meter will automatically read and electronically hold the value of the light level present at the moment when the button was released. Because advanced electronic circuitry and a silicon blue cell are used in the Luna-Pro sbc, the measurement is instantaneous with no memory or lag. This reading will be stored and available for a period of one minute after the button is released. After the one minute period, the meter automatically turns itself off, prolonging battery life. Additional readings can betaken at any time by repeating the above sequence.
	H Getting the Most Out of Your Luna-Pro
		The preceding condensed instructions gave you information on the basic operating procedures for your Luna-Pro sbc. However, this meter is extremely versatile, and the following information will acquaint you with the many creative possibilities available to you when using your Luna-Pro sbc.


		II. a. Continuous or Stored Readings
		The Luna-Pro sbc is capable of either continuously reading or storing light values. For simplicity of operation, the read and hold method is used. For evaluation of different lighting levels such as when using zone systems, the continuous method is used. Both methods are activated by the same power switch.
			To operate the meter in the continuous mode, simply depress and hold the ON/OFF button in. The meter will now respond to all changes in light values. For long term measurements, the ON/OFF switch has a lock position which is indicated by
		To operate the meter in the read and hold mode, the power switch ON/OFF button index mark (a) must be aligned with the square switch position indicator (b). Simply depress and release the In

the round switch position indicator (c). To activate and lock the meter on:					The basic operating difference between the Luna-Pro sbc and a conventional meter is that, instead of using various points along a complete scale length, only one position (the null point) is used for all readings and at all light levels. This results in greater accuracy and ease of operation. There is no need to change scale ranges or to read different scales. When the needle is set at the null point, the computer instantly shows a complete read-out of the measurement. 4www.butkus.org/chinon
1) Depress and hold the power switch in.
2) Rotate the switch button clockwise until the index mark is aligned opposite the round switch position indicator.

The meter will now remain on for constant readings until the switch button is rotated counterclockwise opposite the square position indicator where the read and hold mode will go into operation for one minute, after which the meter will again turn itself off.
					To expand the capabilities of the Luna-Pro sbc further, its meter face is also calibrated in 1/3 EV increments from the null position to ±3 EV for use in scene brightness measurements and zone system applications. Additional information on this extremely useful feature will be found in section II. i.
NOTE: Be sure to return the switch button to the read and hold position (square mark) after using. Failure to do so will result in short battery life.
					If the meter needle is placed in the "over" or "under" range, the readings on the calculator dial will result in over or underexposure by the value indicated, compared to a standard exposure.
II. b. The Null Method of Measurement
Laboratory instruments have long used the null method of measurement for obtaining precise readings. This method has been incorporated into your Luna-Pro sbc for maximum accuracy and ease of reading.					Each numerically indicated major division on the meter face equals one EV (a change of one EV equals a change by one f/stop or one shutter speed setting); the small intermediate dots are equal to 1/3 EV.

II. c. Exposure Correction Dial
Occasionally, the indicated exposure readings obtained with any light meter must be modified for best results. This is especially true when using filters or when taking close-up pictures where the longer lens to film distance results in reduced light at the film plane. To correct for these effects, commonly called filter factor and bellows (extension) factor, additional exposure must be given to the film. In addition, you may, for various creative reasons, wish to depart from the standard exposure values. For these situations, the Luna-Pro sbc, with its exposure correction dial, is ideal.
			To use the exposure correction feature, determine the correction factor desired, in either EV or EF, and rotate the exposure correction dial while holding the computer ring stationary until the white index mark is opposite the correction value. Any readings now taken will reflect this correction. 4www.butkus.org/chinon
			For example, assume that a filter with a filter factor of 4x is being used which represents a change of 2 stops. By moving the index mark of the EF ring to a position opposite the number 4, the meter readings will automatically be compensated for the 2 stop difference.
Normally when making exposure corrections, the correction factor must be calculated and applied each time a reading is taken. However, with the Luna-Pro sbc, the exposure change can be programmed into the exposure correction dial. Any readings then will automatically be corrected as taken.

The exposure correction dial is calibrated to work both in EV (exposure value) and EF (exposure factor). Two index marks are provided at the center or normal positions for each correction method.
In addition, the red exposure correction signal gives a visual indication any time the exposure correction dial is in use.

Rotating the exposure correction dial corrects the indicated exposure by changing the shutter speed (and flash symbol), cine speed, and EV scales. Therefore, this feature can be used for still photography using available light and artificial light including flash, motion picture photography, and with cameras calibrated only in EV.		point the meter toward the light source and take an EV reading (null the meter). Turn the meter over and read the footcandle value opposite the EV reading just obtained. Similarly, lux values can also be determined. Note that for each change of one EV, the footcandle level changes by a factor of 2. This is because the EV scale is equivalent to a full stop scale in that each change of one EV or one f/stop results in either twice or half the amount of light. A formula suitable for calculating intermediate values of footcandles is given in section III along with pre-calculated values at 1/3 EV increments.
	After completing "corrected" measurements, be sure to return the correction dial to its "0" position (red signal will be covered by black tab).

II. d. Footcandle Readings With The Luna-Pro sbc

		For direct reading of footcandles, an accessory snap-on footcandle scale is supplied with the Studio Attachment. When attached, this scale allows quick, direct read-out of the equivalent footcandle readings without having to change ASA values or using a conversion table. Detailed instructions for its use are included with the scale.
The Luna-Pro sbc is a precision instrument designed to give highly accurate photometric readings specified in readily usable photographic terms. However, footcandle readings can also be obtained with the Luna-Pro sbc, either by converting the photographic reading or by use of an accessory snap-on footcandle scale.
		The most precise footcandle readings are obtained by means of a flat diffuser such as the one supplied with the Studio Attachment. When using the spherical diffuser of the Luna-Pro sbc, all the light falling on the diffuser from an angle of approximately 180° is integrated for a final
A conversion table of EV to footcandle readings is included on the underside of the meter. To determine the equivalent footcandle reading, set the ASA film speed scale to 50, slide the spherical diffuser over the cell window for incident readings,

			To insert the meter, open the case by unstrapping the fastener at the rear of the case and swinging the top section forward. Insert the meter strap

reading. Since most photographic subjects are three dimensional, this results in more accurate photographic exposures, but can give improper footcandle readings.
When using the spherical diffuser, footcandle readings are most accurate when reading direct light beams such as from spots, arc lights, etc.
			through the openings at the rear of the case. Place the meter into the bottom section of the case and secure with the retaining strap. To remove the top section of the case completely, unsnap the fastener at the bottom of the case.

II. e. Carrying Case
Your Luna-Pro sbc is supplied with an exceptionally strong and functional carrying case. It is constructed of the finest heavy-duty materials for long life and extra protection for the meter. Extra thick material and heavy stitching make this case suitable for the abuse encountered in professional usage. The complete top section of the case is removable for ease of handling when taking frequent exposure readings. 14


			II. f. Methods of Measurement
			There are two basic methods of obtaining measurements with the Luna-Pro sbc, incident and reflected light readings. Both methods are popular and when used properly, both are valid and will give good results. However, to evaluate

properly the ways in which these two methods function, it is necessary to discuss briefly how the meter operates and how film responds to light. It is beyond the scope of this manual to get into a detailed discussion of sensitometry, the study of tone reproduction. There are many excellent books available on the subject, some of which are listed in the appendix. This manual will just relate in simple terms, how the Luna-Pro sbc works and under which conditions you may wish to use either incident or reflected light readings.			use such a curve to determine exposures, using one as an illustration will help in evaluating proper light measuring techniques. A representative sample H & D curve for a film is illustrated below.

All films have characteristic responses to light which, although they may vary from film to film and with changes in storage and processing, are relatively predictable. This consistency of response is what allows the use of light meters and other photographic instruments to predict the final outcome of an exposure.
			This curve shows, among other things, the change of density of the film vs. the log of the exposure. With negative film, as the exposure increases, the negative density increases. It is broken down into three distinct regions, the toe, straight line portion, and shoulder. In order to record detail properly on film, the light values (log exposure) should fall within the range where they intersect the straight line portion of the curve. If the exposure falls into the area of the toe or shoulder, the film will lose shadow or highlight detail respectively. This is because, once those areas are
Film responds to only a limited range of illumination levels before its ability to record that light illumination level properly is lost. Any instrument designed to measure or expose film must take that into consideration. The response of the film to light is generally graphically illustrated by what is called a "characteristic curve" or H & D curve, named for Hurter and Driffield who originated its use. Although it is not necessary to

reached, little or no change in film density occurs with a change in exposure, and it is the change of density that produces differentiation and detail. Therefore, your light meter must give you an exposure value that will adjust the measured light so that when it reaches the film, it will fall within the straight line portion of the film's recording ability.			as a dark object with a high level of illumination. To standardize these varying conditions and to allow you to work with different meters and films, a reflectance of 18% value and the understanding that it represents a "typical average" is the basis for readings taken with both reflected and incident methods of measurement, although under the same lighting conditions, different readings for the same scene can be obtained when using both methods, depending on subject reflectivity. This may seem strange at first, but it is true, and sometimes causes confusion. To eliminate this confusion (something no meter or other device can do), you must consider your subject matter and how you want it to appear on the film. For simplicity, the discussion of this evaluation method will be broken down into a discussion of incident and reflected light measurements.4www.butkus.org/chinon
The H & D curve shown above indicates relative log exposure. However, because different films have different light sensitivity ranges which would affect the density vs. log exposure in actual use, the meter must be programmed for these differences. The ASA film speed setting control on the calculator dial of the meter accomplishes this programming.
In order for this ASA value to be meaningful, all meters and other light measuring devices that relate to photographic applications must take into account not only the film speed, but also the reflectivity of the object being photographed. This is because the film does not know what the reflectivity of a particular object is. It only responds to light levels. Therefore, all other conditions being equal, a light subject with a low level of illumination may record on film the same

			II. g. Incident Measurement
			When reading incident light, the spherical diffuser is placed in front of the measuring cell window and pointed toward the camera, i.e. opposite the subject being photographed, so that the diffuser will receive the same light intensity and
16

distribution as that falling on the subject. The reading at this point indicates the strength of the light, but does not indicate the light value reflected from the subject into the camera lens and onto the film. It does indicate the light value that would be reflected into the lens from an 18% average reflective subject. Therefore, when working with subjects that are primarily very light or very dark, the incident exposure reading indicated should be adjusted to compensate for the difference in reflectivity from the 18% standard. When the subject is very light, decrease the exposure by 1/2 to 1 f/stop. When the subject is very dark, increase the exposure by 1/2 to 1 stop. The amount of change to the exposure will depend on your judgement as to the degree of variation in subject reflectivity from an average scene.		Situations may arise where you have extremes of light and dark subjects, all of which are important in the same scene. Under these conditions, the meter should be used in the reflected light method as described under scene brightness range and zone systems.
		Incident light readings are most valuable when determining exposures where the subject is inaccessible and receives the same illumination as the meter. They also allow you to determine the individual strengths of multiple light sources striking one subject by reading each source independently. In most cases with average subject matter, the incident method is a fast, simple and accurate way to determine exposure.

		II. h. Reflected Measurement When reading reflected light, the meter is pointed toward the subject and light reflected from the subject passes through a collecting lens onto the measuring cell. This is the same type of path the light takes when exposing film in your camera. The meter cannot "read" any single element in its field, such as a face or highlight; it integrates all the light reflected throughout the measuring field, and indicates an exposure which will record the total picture on the basis of an overall 18% value.

I. c. Setting the Film Speed				I. d. Exposure Factor Scale
Determine the ASA speed from the data supplied by the film manufacturer. Rotate the clear film speed setting disc (16) by the raised bars until the ASA speed number is opposite the white ASA index triangle (8). A detailed ASA film speed table in on page 35.				Check to make sure that the exposure factor scale (10) index mark (18) is at 1. A more detailed explanation of this useful scale is on page 9.


	KODAK Filters for Scientific and Technical Uses, 1st Ed. B-3