Light meters
Gossen Luna-Pro sbc User manual
User manual for Gossen Luna-Pro sbc. 41 pages in English. Read the original PDF, download or print a copy without registration.
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- Brand
- Gossen
- Model / document
- Gossen Luna-Pro sbc
- Document type
- User manual
- Language
- English
- Pages
- 41
- File size
- 4.0 MB
- Category
- Light meters
- Document date
- Not specified in catalog
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Page 1 · Read text
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Luna-Pro
ffimffiView original page 1Page 2 · Read text
!This Luna-Pro sbc Instruction Manual is more than Congratulations
just an instruction book it is actually a short - of an exposure meter. You now own the most advanced exposure meter,course in the creative use
the heart of the Luna-Pro sbc System.
Section loffers "Basic Operating Instructions", To f lexible,use your Luna-Pro sbc properly you need only read The new Luna-Pro sbc System is the most
and follow the simple instructions in this section. versatile and adaptable photographic light measuring system ever devised, while at the same
moves step forward however, aSection get ll,
"Getting sbc. Of Your Luna-Pro Most Out the -Hereto timemaximumbeingbenefitvery simplefrom totheuse.qualityIn orderdesignto and
you can really find out how to put the unique operating features of this precision instrument,
versatility of your Luna-Pro sbc to work for You. . please take a few minutes to read this instruction
Section lll gives you "Helpful Hints" for special manual.
shootings * action, snow and sand, sunsets, Your new Luna-Pro sbc utilizes the latest advances
night, and more - the type of information you need in silicon cell sensors and also high performancefor that extra creativity. electronic circuitry including integrated circuits to
And Section lV provides you with f ull details on the provide fast, accurate, repeatable readings under
"Accessories" for your Luna-Pro sbc to turn it the most difficult professional conditions. -into a true exposure system. The Luna-Pro sbc represents a most significant
We sincerely hope that this manual will be of help development by Gossen GmbH, Erlangen, West
to you and will answer most of your exposure Germany, Europe's largest manufacturer ofmeasurement questions. lf it does not, feel free to precision electrical instruments since 1919, and
contact your BMG specialist dealer. In addition, our one of the outstanding pioneers in exposure meterConsumer Service Department is available for help design since 1932. i
with special requests.
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l. c. Setting the Film SPeed l. d. Exposure Factor Scale Determine the ASA speed f rom the data supplied by Gheck to make sure that the exposure factor scalethe film manufacturer. Rotate the clear film speed (10) index mark (18) is at 1. A more detailed expla-setting disc (16) by the raised bars until the ASA nation of this useful scale is on page 9.speed number is opposite the whlte ASA index tiiangle (8). A detailed ASA f ilm speed table in on page 35.View original page 6
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Aim the meter at the subject for a reflected light l. e. Making a Measurement reading or at the camera tor an incident reading.
Select the method of measurement desired, either Depress and release the power switch (4). Rotate
reflected or incident. (For details on incident vs. the computer dial (11) until the meter needle is over
reflected measurements, see section ll. f. For re- the "0" null line. Read the desired combination of
flected readings slide the spherical diffuser (1) to f/stops and shutter speeds on the computer
scales.
NOTE: When you release the power switch, the
value measured at that moment will be automati-
cally 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 forconvenient and repeated reference. For
either side of the meter. For incident readirgs, continuous measurements, see page 10.
slide the sperical diffuser in front of the measuring
cell window (19) until it "snaps" into the detent.-
l. 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.
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The time, or shutter speed, scale is calibrated
from 1/4000 of a second to 8 hours and indicates EXAM PLES:
values as follows:
ASA 25,000 at HIGHEST LIGHT LEVEL: Hours are indicated 8h, 4h, etc. 1/ 4000 sec at t / 128 Minutes are indicated 30m, 15m, etc. Scales show (above) hours at f/5.6 etc. Seconds are indicated 30, 15, etc. but also (below) 8
Fractional seconds are indicated '2,'4, etc.
Obviously, HIGH ASA and HIGH light level add up
Note that each section is alternately colored from to SHORT exposure 1l4OO0 sec. at l/128.the adjacent sections for ease of reading. The red 0l -
indicates the proper reading point when using the
electronic flash attachment. See page 32. ASA 0.8 At LOWEST LIGHT LEVEL:
Scales show (above) 8 hours at t/2.8 etc.The ASA scale is calibrated in standard ASA but also (below; 1/4000 sec. at f /64 etc.values from 0.8 to 100,000 (100K). Intermediate
values are shown by short lines. A complete table Obviously LOW ASA and LOW light level add up
listing these intermediate values is on page 35. to,LONG exposre - 8 hours al t/2.8.
fromCAUTION: Because of the extreme measuring The aperture or f/stop scale is calibrated t / 128 to f /0.7 . Numerical values are shown on therange of the Luna-Pro sbc, it is possible under - light scale at full f/stop increments. Intermediateexceptional conditions of very high or low stoplevels combined with a very high or low ASA index values are indicated by short lines at 1/3
that the computer displays both ends of the increments. A table of intermediate values and the- time scale (8h and 1/4000 sec). When mathematical formula for calculating f/stops areexposure
this occurs, the CORRECT reading will be the given in section lll.
UPPER part of the scales!
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www.butkus.us The cine scale allows direct reading of apertures An EF (exposure factor) scale is included for for various cine speeds (frames per second). making exposure corrections when using filters, These speeds correspond to actual exposure bellows, extension tubes, etc. lt is calibrated for times on the exposure time scale only for cameras exposure factors up to 64.. Detailed information on having standard shutter angles. For XL cameras or this scale is in section ll. c. 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 f ilm 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. 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. lt is important to remember that a change of 1 EV is equivalent to a change of 1 f /stopView original page 10
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power switch. The meter will automatically read
and electronically hold the value of the light level
present at the moment when the button was
Because advanced electronic circuitry Getting the Most released. and a silicon blue cell are used in the Luna-Pro Out of Your Luna-Pro sbc, the measurement is instantaneous with no
andThe preceeding condensed instructions gave you memory or lag. This reading will be stored theinformation on the basic operating procedures for available for a. period of one minute after
your Luna-Pro sbc. However, this meter is button is released. After the one minute period,extremely versatile, and the following information the meter automatically turns itself off , prolonging
will acquaint you with the many creative battery life. Additional readings can.be taken at anypossibilities available to you when using your time by repeating the above sequence.
Luna-Pro sbc.
ll. a. Gontinuous 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,
To operate the meter in the read and hold mode, simply depress and hold the ON/OFF button in.
the power switch ON/OFF button index mark (a) The meter will now respond to all changes in light
must be aligned with the square switch position vaf ues.'For long term measurements, the ON /OFF
byindicator (b). Simply depress and release the switch has a lock position which is indicated
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the round switch position indicator (c). To activate The basic operating dif ference between the
and lock the meter on: Luna-Pro sbc and a conventional meter is that,
1) Depress and hold the power switch in. instead of using various points along a complete scale length, only one position (the null point) is
2) Rotate the switch button clockwise until the used for all readings and at all light levels. This index mark is aligned opposite the round results in greater accuracy and ease of operation.
switch position indicator. There is no need to change scale ranges or to read
different scales. When the needle is set at the nullThe meter will now remain on for constant point, the computer instantly shows a completereadings until the switch button is rotated read-out of the measurement.
counterclockwise opposite the square position To expand the capabilities of the Luna-Pro sbcindicator where the read and hold mode will go further, its meter face is also calibrated in 1/3 EVinto operation for one minute, after which the increments f rom the null position to 3 EV for usemeter will again turn itself off . t in scene brightness measurements and zone
NOTE: Be sure to return the switch button to the system applications. Additional information on
read and hold position (square mark) after using. this extremely useful feature will be found in
Failure to do so will result in short battery life. section ll. i.
lf 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 valuell. b. The Null Method of Measurement indicated, gompared to a standard exposure.
Laboratory instruments have long used the null Each numerically indicated major division on themethod of measurement for obtaining precise meter face equals one EV (a change of one EV
readings. This method has been incorporated into equals a change by one f/stop or one shutter
your Luna-Pro sbc for maximum accuracy and speed setting); the small intermediate dots are
ease of reading. equal to 1/3 EV.
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ll. c. Exposure Correction Dial gives a visudl ind\ication any time the exposure correction dial is in use.Occasionally, the indicated exposure readings obtained with any light meter must be modif ied for To use the exposure correction feature, deter- eitherbest results. This is especially true when using mine the correctign factor desired, ih filters or when taking close-up pictures where the EV or EF, and rotatb the exposure correction dial longer lens to f ilm distance results in reduced light while holding the computer ring stationary until at the film plane. To correct for these effects, the white index mark is opposite the correctioncom mon ly called f ilter f actor and bellows value. Any readings now taken will reflect this (extension) factor, additional exposure must be correction. given to the f ilm. In addition, you lTlay, for various For example, assume that a f ilter with a f ilter factor creative reasons, wish to depart from the standard of 4x is being used which represents a chan ge of 2 exposure values. For these situations, the stops. By moving the index mark of the EF ring to Luna-Pro sbc, with its exposure correction dial, is a position opposite the number 4, the meter ideal. readings will automatically be compensated for Normally when making exposure corrections, the the 2 stop difference. 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 norrnal positions for each correction method. in addition, the red exposure correction signal www.butkus.us 12View original page 13
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Rotating the exposure correction dial corrects the point the meter toward the light source and takeindicated exposure by changing the shutter speed an EV reading (nullthe meter). Turn the meter over
(and flash symbol), cine speed, and EV scales. and read the footcandle value opposite the EV
Therefore, this feature can be used for still reading just obtained. Similarly, lux values can also
photography using available light and artificial be determined. Note that for each change of one
light including f lash, motion picture photography, EV, the footcandle level changes by a factor of 2.
and with cameras calibrated only in EV. This is because the EV scale is equivalent to a full
stop scale in that each change of one EV or one
After completing "corrected" measurements, be f /stop results in either twice or half the amount of sure to return the correction dial to its "0" posi- light. A formula suitable for calculating inter- tion (red signal will be covered by black tab). mediate values of footcandles is given in section lll
along with pre-calculated values at 1/3 EV
increments.ll. d. Footcandle Readings
With The Luna-Pro sbc For direct reading of footcandles, an accessory
The Luna-Pro sbc is a precision instrument snap-on footcandle scale is supplied with the
designed to give highly accurate photometric Studio Attachment. When attached, this scale
readings specified in readily usable photographic allows quick, direct read-out of the equivalent
terms. However, footcandle readings can also be footcandle readings withou.t having to change ASA
obtained with the Luna-Pro sbc, either by values or using a conversion table. Detailed
converting the photographic reading or by use of instructions for its use are included with the scale.
an accessory snap-on footcandle scale. The most precise footcandle readings are obtained
A conversion table of EV to footcandle readings is by means of a flat diffuser such as the one
included on the underside of the meter. To supplied with the Studio Attachment. When using
determine the equivalent footcandle reading, set the spherical diffuser of the Luna-Pro sbc, all the
the ASA f ilm speed scale to 50, slide the spherical light falling on the diffuser from an angle of
diff user over the cell window for incident readings, approximately 180" is integrated for a final
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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 r I 111 a7 +L /w
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 through the openings at the rear of the case. Placelight beams such as from spots, arc lights, etc. the meter into the bottom section of the case and
secure with the retaining strap. To remove the topli. e. Garrying Case section of the case completely, unsnap the fastener
Your Luna-Pro sbc is supplied with an at the bottom of the case.
exceptionally strong and functional carrying case.
It is constructed of the f inest heavy-duty materials ll. f. Methods of Measurementfor long life and extra protection for the meter.
Extra thick material and heavy stitching make this There are two basic methods of obtainingcase suitable for the abuse encountered in measurements with the Luna-Pro sbc, incident
professional usage. The complete top section of and reflected light readings. Both methods are
the case is removable for ease of handling when popular and when used properly, both are valid
taking frequent exposure readings. and will give good results. However, to evaluate
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www.butkus.us properly the ways in which these two methods use such a curve to determine exposures, using
function, it is necessary to discuss brief ly how the one as an illustration will help in evaluating proper
meter operates and how film responds to light. lt light measuring techniques. A repres-entative
is beyond the scope of this manual to get into a sample H & D curve for a film is illustrated below. 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 ref lected light readings.
Alt films have characteristic responses to light
which, although they may vary f rom f ilm to f ilm
2.4Oand with changes in storage and processing, are 1.50 1.80 2.1Q
relatively predictable. This consistency of
response is what allows the use of light meters This curve shows, things, the changeand other photographic instruments to predict the of density of the film"ronn'uJffvs. the log of the exposure.
final outcome of an exposure. With negative film, as the exposure increases, the
negattve density increases. lt is broken down intoF.ilm responds to only a limited range of three distinct regions, the toe, straight lineillumination levels before its ability to recoid that portion, and shoulder. In order to record detaillight illumination level properly is lost. Any properly on film, the light values (log exposure)instrument designed to measure or expose film should fall within the range where they intersectmust take that into consideration. The response of the straight line portion of the curve. lf thethe film to light is generally graphically illustrated exposure falls into the area of the toe or shoulder,by what is called a "characteristic curve" or H & D the film will lose shadow or highlight detailcurve, named for Hurter and Driffield who respectively. This is because, once those areas areoriginated its use. Although it is not necessary to
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\
reached, little or no change in film density occurs as a dark object with a high level of illumination.
with a change in exposure, and it is the change of To standardize these varying conditions and to
density that produces differentiation and detail. allow you to work with different meters and films,
Therefore, your light meter must give you an a ref lectance of 18% value and the understanding
exposure value that will adjust the measured light that it represents a "typical average" is the basis
so that when it reaches the film, it will fall within for readings taken with both ref lected and incident
the straight line portion of the film's recording methods of measurement, although under the
ab i lity. same lighting conditions, different readings for
the same scene can be obtained when using bothThe H & D curve shown above indicates relative log methods, depending on subject reflectivity. Thisexposure. However, because different films have may seem strange at first, but it is true, anddifferent light sensitivity ranges which would sometimes causes confusion. To eliminate thisaffect the density vs. log exposure in actual use, confusion (something no meter or other devicethe meter must be programmed for these can do), you must consider your subject matterdifferences. The ASA f ilm speed setting control on and how you want it to appear on the film. Forthe calculator dial of the meter accomplishes this simplicity, the discussion of this evaluationprogramming. method will be broken down into a discussion of
In order for this ASA value to be meaningful, all incident and reflected light measurements.
meters and other light measuring devices that
relate to photographic applications must take into
account not only the film speed, but also the ll. g. Incident Measurement ref lectivity of the object being photographed. This
is because the film does not know what the When reading incident light, the spherical diffuser
reflectivity of a particular object is. lt only is placed in front of the measuring cell windowresponds to light levels. Therefore, all other and pointed toward the camera, i.e. opposite the
conditions being equal, a light subject with a low subject being photographed, so that the diffuser
level of illumination may record on film the same will receive the same light intensity and
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distribution as that lalling on the subject. The Situations may arise where you have extremes of
value in the same scene. Under these conditions, thel readinglight, butat thisdoespointnotindicatesindicatethethestrengthlight of the light and dark subjects, all of which are important reflected from the subject into the camera lens and meter should be used in the ref lected light method
onto the f ilm. lt does indicate the light value that as described under scene brightness range and
would be reflected into the lens from an 18oh zone systems.
average reflective subject. Therefore, when Incident light readings are most valuable when
working with subjects that are primarily very light determining exposures where the subject is or very dark, the incident exposure reading inaccessible and receives the same illumination as
indicated should be adjusted to compensate for the meter. They also allow you to determine the the difference in reflectivity from the 18o/o individual strengths of multiple light sources
standard. When the subject is very light, decrease striking one subject by reading each source
the exposure by 1/2 to 1 f /stop. When the subject independently. In most cases with average subject
is very dark, increase the exposure by 1/2 to 1 matter, the incident method is a fast, simple and
stop. The amount of change to the exposure will accurate way to determine exposure.
depend on your judgement as to tllg degree of
variation in subject reflectivity ll. h. Reflected Measurement
from an average scene. 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 ref lected throughout the measuring f ield,
and indicates an exposure which will record the
totaf picture on the basis of an overall 18o/o value.
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In most cases, you can simply use this reading to When measuring a subject that departs signifi-
get a perfectly exposed picture. However, there are cantly from an 18o/o reflective surface, you may
a few situations where the readings should be wish to modify your readings. This is because the
modified. reading indicated will make the subject appear on I
the film as if it were 18o/o reflective. ?The Luna-Pro sbc has a measuring angle of 30'
when taking a reflected reading. The light from all tn certain cases, you may not want the subjectobjects within that 30' measuring range will be being measured to fall into that category. Foraveraged to give you the f inal reading. lf you have example, if the indicated reading is set in yourone or more objects that are significantly lighter or camera when measuring a brilliant white bridaldarker than the rest of the scene, the objects will gown, the resulting image of the gown on the filmbias the reading away from the average. In cases will appear with the same density as if it were 18o/osuch as this, the meter should be moved in closer gray instead of white. Here again, you may wish toto the main subjects of interest or one of the use an incident reading or compensate theaccessory spot attachments used to eliminate the ref lected reading by increasing exposure. The sameeffect of the light or dark areas. As an alternative, is true for very dark objects, i.e., a black tuxedo,an incident reading can be taken. except the exposure would be decreased.
Reflected readings are particularly useful when
trying to evaluate the relative range of reflected
light from various subjects that may have different
ref lectivity and may be receiving different amounts
of light. Because the reflected reading measures
the light reaching the lens, differences in
ref lectivity and level of illumination are accounted
for. Therefore, you can determine the extremes and
distribution of light from the scene just the way
18
.l IView original page 19Page 20 · Read text
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your f ilm will record it. This technique is covered in To utilize this function, you must first determine,
sections Scene Brightness Range and Zone by testing the limits of exposure change for
Systems. highlight and. shadow areas from average that are
acceptabJe to you with your f ilm. Once this is done,
the cal'ibrated reference scale on the meter willll. i. Scene Brightness Range automatically indicate if you are within acceptable
In order to assure proper exposures for highlight limits of the film.
and shadow detail in scenes with a wide range of For example, if your testing with a particular type of
light intensity and subject ref lectivity, the extent of film shows that you could accept an exposure
f rom average of UNDER (under exposure) 2the lighting range must be determined. The change
Luna-Pro sbc is ideally suited for this type of to OVER (over exposure) 21/z EY, your total range
measurement because of its null meter design. would be 41/z EV. Using reflected measurement,
you could then read the light from the most impor-
tant area of the scene and then null for that reading.
Then, without further adjustment of the calculator
dial, you could take light readings from highlight
and shadow areas and read the EV variance of these
areas. lf , in this case, the readings fall within the
UNDER 2 to OVER 21/z EV range, your exposures
will be good. However, if for example, your
readings resulted in UNDER 3 and OVER 1, you
3, 3 2r 0 0 .1 *I. r lr r uiltlHR 1\ ;'\. ' svufr
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would lose shadow detail, even though the total
range is still only 4 EV. A simple solution would
then be to reread the shadow intensity and rotate
the computer dial until the meter needle is opposite
2 on the UNDER side which is within the f ilm limits. il
. il Fozulo
t-I
0.30 0.60 0.90 1.20 1.50 1.80 2.10
RELATIVE LOG E
Then recheck the highlights which should now read
OVER 2. You would then use the new exposure
setting indicated on the computer dial. The
scene brightness range has not changed, but the
meter has adjusted to yourt exposure so that you are
working within the range of the film. To see this
graphically in terms of f ilm response see the H & D
curves to the right.
It is important to note that this exposure
adjustment method works best when using 0.0 0.30 0.60 0.90 1.20 1.50 1.80 2.10
negative films because different density levels can RELATTVE LOG Ebe adjusted for in printing. With transparency
f ilms, this type of exposure adjustment should be With transparencies, about 1 EV is the largest
used very carefully because you are viewing the practical shift if your main subject is close to 18%
original without the benefit of printing correction. ref lectance.
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adjusted so that the most important parts of the central zone determines the amount of exposure scene receive proper exposure. This can be done correction and processing modif ication, if any, that with either black and white or color f ilm. However, is needed. With most meters, the zone equivalents some detail, either in the highlight or shadow must be marked on the face or transferred to areas, will be lost. another sheet to correlate with changes in light level. However, with the Luna-Pro sbc, theWhen using black and white film, sflother computer dial can be used to adjust the metertechnique is available to extend the capabilities of the film to record extreme lighting ranges. lt is needle to null at any light level. Any subject can be nulled for and light variations from that level readcalled the zone system. Instead of relying on directly off the meter face in EV. This means thatstandard measurement and exposure techniques, you can always set null for Zone 5. Or, you maythe zone system combines special measurement wish to bias the reading in one direction.techniques, modified exposures, and altered film processing to expand the range of light values that Simply turning the computer dial of the Luna-Pro the film can accept. ln doing so, detail can be sbc allows you to put the meter needle anywhere recorded which would otherwise be lost. from -3to +3 EV from a normal value. With a little A complete discussion of this technique is tar practice, you will be amazed at the ease with which specialized information chn be gotten.beyond this manual. References are given in the appendix which should help you become familiar ll. l. Film Reciprocity Failure with this very useful photographic tool. All photographic exposure meters rely on a The Luna-Pro sbc is well suited for use with most principle of film exposure called recipro- zone systems because of its null meter principle of city, to function properly. Basically, the filmoperation. Most systems are based on a central integrates or adds up light ouring exposure tozone, representing a certain lighting level, called produce the latent imaoe. Within certain limits,Zone 5. From this level, the range of light from the same image density is acheived for shorthighlight to shadow is measured and referred to exposures of high intensity as with long exposuresthis central zone. The level of variance from the of low intensity, as long as the product of intensity 22View original page 23
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times time is constant. When the exposure times raise it to the power .25 wh ich is the deci'mal
get very long or very short, however, this reciprocity equivalent of 1/4 stop. effect is lost, and an accurate prediction of
exposure, and color balance with color films, .zSs (lW})f-,7 t,oj cannot be determined solely by the meter reading. (ry) It is therefore important to check the instructions Next multiply 4 times 1.09 - supplied with the film in use to determine when
reciprocity failure can be expected, how severe it will be, and how to correct for it. Here again the (0 Go)=4* Luna-Pro sbc greatly assists in exposure Your new f/stop is approximately 4.4. determ ination because the corrective f ilters
suggested by film manufacturers to adjust color
shifts from reciprocity failure have an effect on ll. n. lltermediale Footcandle Values andexposure. These f ilter factors can be programmed Exposure Times into the Luna-Pro sbc, and the new, corrected Galculation of intermediate values of footcandlesf/stop read directly. and exposure times is basically the same as
intermediate values of f /stops ll. m. Intermediate f/stops calculation of except that the value \l- is reptaced by 2 in theThe Luna-Pro sbc is calibrated in 1/3 f /stop formula.
increments with numerical indications at f uil For example, you have a footcandle level 1/2 stopstops. A table is included below with the actual above 1000 as represented on the chart on the backnumerical values of the 1/3 stop increlnents listed of the Luna-Pro sbc.for levels from t/0.7 lo f /128.Values not listed can
be calculated from the formula that follows. New footc'andle level = (old feveD Q $/stoP change);
(1000) (2 (.5)1New f /stop = (old f /stop) ( \- (f /stop change); =
For exampte, if you ,wish to stop down 1/4 stop (1000( (1.414)
from f/4, take the \2-which equals 1.414 and 1414 29View original page 24Page 25 · Read text
toward or away from you can be stopped with a
lower shutter speed than those moving across your
field. To create a more realistic feeling of motion
with objects moving across your f ield, use a slower
shutter speed and pan across the field. When
panning, the relative speed between the subjectHelpful Hints and the camera is decreased while the relative
speed between the background and camera is lll. a. Chqgsing pe_twegn {clion Stopping Ability ahd Depth-of-Field increased. This results in the characteristic action shot with the main subject sharp and theAfter taking a light reading with your Luna-Pro sbc, background blurred.you will have a choice of readings to use which may
look like this: For shutter speeds of 1/60 second and longer, the
use of a good tripod or other camera support is
blurredTime: 1/1000 1/500 1/250 1/125 suggested to avoid camera shake and pictures.t/ 2 2.8 4 5.6
major factor in yourTime: 1/60 1/30 1/15 1/8 When subject speed is not a longerU8 11 16 22 pictures, you may wish to choose a exposure time and stop down for maximum
All of them will give good exposures, but, in terms depth-of-f ield. This extra depth may be especially
important when using long lenses because of theirof photographic results, they are all slightly
dif f erent. relatively shallow depth-of-field. However, with
long lenses, camera shake is accentuated so beWhen shooting action, you generally need a faster careful to use a sturdy support.shutter speed to get a sharp photograph. Speeds
from 1/125 to 1/1000 are generally used, with the Conversely, even when subject speed is not a major
choice depending upon the relative speed and factor, you may still wish to choose a short shutter
direction of travel of the object. Objects moving speed and a larger lens opening to intentionally
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