This condition results in a color shift in an area of under or over exposure that cannot be corrected without affecting the colors of the properly exposed areas of the scene. It is therefore very important to avoid this condition which shows itself as color shifts in the shadows and highlights.
Zone Systems There are times when the lighting range cannot be brought within the acceptable limits of the film because of an inability to fill or use "gobos" as spelled in manual such as when photographing landscapes. When these situations arise, the exposure levels can be adjusted so that the most important parts of the scene receive proper exposure. This can be done with either black and white or color film. However, some detail, either in the highlight or shadow areas, will be lost.
When using black and white film, another technique is available to extend the capabilities of the film to record extreme lighting ranges.
It is called the zone system. Instead of relying on standard measurement and exposure techniques, the zone system combines special measurement techniques, modified exposures, and altered film processing to expand the range of light values that the film can accept.
In doing so, detail can be recorded which would otherwise be lost. A complete discussion of this technique is far beyond this manual. References are given in the appendix which should help you become familiar with this very useful photographic tool. The Luna-Pro F is well suited for use with most zone systems because of its null meter principle of operation and the zone system scales Most systems are based on a central zone, representing a certain lighting level called Zone 5.
From this level, the range of light from highlight to shadow is measured and referred to this central zone. The level of variance from the central zone determines the amount of exposure correction and processing modification, if any, that is needed. With most meters, the zone equivalents must be marked on the face or transferred to another sheet to correlate with changes in light level.
However, with the LunaPro F. Any subject can be nulled for and light variations from that level read in zone system values I thru IX directly off the meter face in EV. This means that you can always set null for Zone 5. Or, you may wish to bias the reading in one direction. To use the zone system scales of the Luna-Pro F. Using the EV scale as a reference point, measurements of highlight and shadow areas can then be translated into zone values.
Example: Take a reading of a central zone or mid-tone Zone V and null the meter. Assume the EV indicated for Zone V is '8'. Note the EV values indicated for the other zone values. Assuming the highlight reading corresponds to an EV 12, the zone value would then be Zone IX see chart above. Now take a shadow reading, null the meter and note the EV indicated. The zone system scale of the Luna-Pro F enables you to easily measure zone system values and establish information regarding tonal range in a scene.
In the example above, Zone V a mid-tone is used as a reference point; however, with the Luna-Pro F you can select any zone or light level as a reference. A reading is taken of a particular area, the meter is nulled and the EV value noted i. If you would like that area to be represented as a Zone III rotate the computer dial until EV 7 is directly above Zone value lilt At this point, a reading of the appropriate apertures and shutter speeds will render the particular area measured as a Zone III.
With a little practice, you will be amazed at the ease of obtaining this specialized information. Film Reciprocity Failure All photographic exposure meters rely on a principle of film exposure called reciprocity, to function properly. Basically, the film integrates or adds up light during exposures to produce the latent image.
Within certain limits, the same image density is achieved for short exposures of high intensity as with long exposures of low intensity, as long as the product of intensity times time is constant.
When the exposure times get very long or very short, however, this reciprocity effect is lost, and an accurate prediction of exposure, and color balance with color films, cannot be determined solely by the meter reading. It is therefore important to check the instructions 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 Luna-Pro F greatly assists in exposure determination because the corrective filters suggested by film manufacturers to adjust color shifts from reciprocity failure have an effect on exposure.
Values not listed can be calculated from the formula that follows. All of them will give good exposures, but, in terms of photographic results, they are all slightly different. When shooting action, you generally need a faster shutter speed to get a sharp photograph. Objects moving 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 you field, use a slower shutter speed and pan across the field. When panning, the relative speed between the subject and the camera is decreased while the relative speed between the background and camera is increased. This results in the characteristic action shot with the main subject sharp and the background blurred. When subject speed is not a major factor in your pictures, you may wish to choose a longer exposure time and stop down for maximum depth-of-field.
This extra depth may be especially important when using long lenses because of their relatively shallow depth-of-field. However, with long lenses, camera shake is accentuated so be careful to use a sturdy support. Conversely, even when subject speed is not a major factor, you may still wish to choose a short shutter speed and a larger lens opening to intentionally limit depth-of-field for selective focus. This is especially useful for eliminating the distraction of cluttered backgrounds.
Portraits lend themselves ideally to this technique. You should first determine what part of the scene is most important. Using an incident reading under these conditions will generally give you poor exposures with washed-out colors. Reflected readings are more accurate, but some compensation is still necessary for the sun or sky. When the sun is present and most important, read the sun directly and use that exposure.
If the sky and clouds are most important, read these areas, being careful not to read direct sunlight. In all cases, if practical, bracket exposures on both sides of those indicated. You may get some very striking results that are not apparent to the unaided eye. Generally, night exposures get into the area of film reciprocity failure. It is therefore important to know the characteristics of your film before shooting under these conditions.
Copying Copying places stringent demands on lighting to make sure that the detail and tonal range of the original is recorded on the copy. Lights are usually placed to the sides of the copyboard to eliminate glare from the surface of the copy.
Many people prefer to overlight the corners of the copy to compensate for lens falloff. For copy work, the Luna-Pro F can be used with the Copy Attachment for determining exposure and checking evenness of illumination. There are several ways to correct for this effect.
Two of the most commonly used take into account the lens focal length and the lens to film plane distance bellows extension. The first method gives you an extension factor which can be programmed into the exposure factor ring of the Luna-Pro F for direct readout of corrected exposure values. The second method gives a corrected aperture only. For example, assume a mm lens approximately 8" is being used with a lens to film plane distance of 14".
Note that the exposure factor portion of the ring numbers in black should be used, not the EV position. All readings will now be corrected for this extension factor. Another way to determine extension factor is to measure the magnification of the object size at the film plane.
This is especially useful when working with large format cameras where measurement of the image on the ground glass is relatively easy. To calculate the extension factor, measure both the actual object size and the size of the image on the ground glass.
These two measurements are used in the formula below. For example, assume an object size of 2 inches and image size of 4 inches. Setting 9 in the EF correction ring of the Luna-Pro F will give correct exposures for this condition. Extension and filter factors can be eliminated from exposure reading by using the accessory fiber optics probe and reading on the camera groundglass.
Any changes due to these factors will automatically be sensed and compensated for by the meter. Accessories All of these excellent features are only the beginning of the Luna-Pro F story. The wide range of instantly interchangeable accessories set the LunaPro F distinctly apart from other light measuring instruments. For direct reading with proper exposure values, make the following exposure corrections when using your Luna-Pro attachments with your Luna-Pro F Exposure Meter. When using the 7.
Readings are then taken normally. For complete instructions on how to use these and other attachments with your Luna-Pro F. Enlarging Attachment. Your Gossen Luna Pro F is your valuable precision instrument, made with great care and accurately calibrated. It deserves your good care! The battery and zero position tests described on page 5 enable you to check the proper functioning of your Luna-Pro F. If meter is to be stored for extended periods of time, remove the battery from the meter.
Measuring comparisons of your Luna-Pro F with similar or other types of exposure meters cannot be made properly without special laboratory equipment optical bench. Do not attempt to open or repair your Luna-Pro F.
Service information appears below. Service Should your Luna-Pro F require service, send the meter directly or through an authorized dealer , in the original packing, if possible, prepaid and insured to:.
III and Zakia R. Section I. Zeroing the Meter 5 I. Setting the Film Speed 6 I. Exposure Factor Scale 6 I. Type of Reading 7 I. Mode of Measurement 7 I. Taking a Measurement 7 I. Reading the Scales 8 Section II. Continuous or Stored Readings 11 II. Exposure Correction Dial 13 II. Footcandle Readings 14 II. Carrying Case 15 II.
Methods of Measurement 15 II. Incident Measurement 17 II. Reflected Measurement 18 II. Scene Brightness Range Lighting Ratios 22 II. Color Crossover 26 II. Zone Systems 27 II. Film Reciprocity Failure 28 II. Helpful Hints a Sunsets 31 III.
Night Lighting 32 III. Backlighting 32 IlI. Copying 33 III. Excessive Skylight 33 III. Spherical Diffuser 2. Green Zero Check Point 3. Meter Needle 4. Power Switch 5. Electronic Flash Reference Mark 6. Cine Scale 7. Mode Selector 8. ASA Index Triangle 9. Film Speed Scale Exposure Correction Dial Computer Dial. Battery Test Zone Flash Range Indicator Exposure Time Scale Aperture Scale Battery Test Button Exposure Correction Signal Film Speed Setting Disk Exposure Value Scale Zone System Scale Exposure Factor Scale Index Mark.
Measuring Cell Window under diffuser Zero Adjusting Screw. Battery Compartment Lid. 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 23 until the needle rests on the zero mark.
Determine the ASA speed from the data supplied by the film manufacturer. Rotate the clear film speed setting disc 18 by the raised bars until the ASA speed number is opposite the white ASA index triangle 8. A detailed ASA film speed table is on page Check to make sure that the exposure factor scale index mark 21 is at 1. A more detailed explanation of this useful scale is on page Select the method of measurement desired, either reflected or incident. For details on incident vs.
For reflected readings slide the spherical diffuser 1 to. 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. Once determined, the correction can be programmed into the exposure correction dial. The meter will now respond to all changes in light values. To activate and lock the meter on:. 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 desired.
Any readings now taken will reflect this correction. The most precise foot candle readings are obtained by means of a flat diffuser. When using the spherical diffuser of the Luna-Pro F. Your Luna-Pro F 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. If you have one or more objects that are significantly lighter or darker than the rest of the scene, the objects will bias the reading away from the average. In cases such as this, the meter should be moved in closer to the main subjects of interest or one of the accessory spot attachments used to eliminate the effect of the light or dark areas.
As an alternative, an incident reading can be taken. In order to assure proper exposures for highlight and shadow detail in scenes with a wide range of light intensity and subject reflectivity, the extent of the lighting range must be determined. The LunaPro F is ideally suited to this type of measurement because of its null meter design.
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 your exposure so that you are working within the range of the film. Situations may arise where the meter shows a range of light intensity that is beyond the total range of film acceptance.
In these cases, the use of fill light to lighten shadows or a "gobo" a device to block or modify light such as a dark card to soften highlights may be indicated. When the proper corrective action is taken, the scene brightness range can again be checked to be sure the limits of the film are not exceeded.
When photographing with highly reflective surfaces such as snow and sand, extreme care should be used when using reflected readings.
In most cases, an incident reading will produce superior results for normal subject in the scene, although the snow or sand may be overexposed. If reflected readings are desired, the main subject should be metered up close or a spot attachment used to minimize the effect of the reflected light, unless the snow or sand is itself the most important part of the scene.
This is an ideal time to use scene brightness range measurements. Sunsets can present a problem in light measurement because of brightness range. Sometimes, the sun itself is the most important part of the scene and at other times, light reflecting from clouds or distant mountains may be more important.
Measurement of illumination levels at night presents several problems to good exposures. Generally, in outdoor scenes, the lighting is not as uniform as with daylight. Bright artificial lights can create multiple highlights and shadows, with a tremendously large brightness range. In addition, direct use of the meter readings will result in a picture that appears more like a daylight photo than one taken at night. When the main subject of interest is backlit, care should be exercised when taking reflected readings.
Light from behind the subject entering directly into the measuring cell of the meter will produce reading errors.
To avoid this, take your readings up close to the subject or use one of the spot attachments for more accuracy. An incident reading can also be used, with the meter pointed towards the camera. When taking reflected readings of scenes where there are large areas of skylight, care should be exercised that the main subject be given the greatest attention either by tilting the meter down taking up-close measurement or by using one of the spot attachments.
As an alternative, an incident reading may be used. When photographs are taken where the focus is at a point other than infinity, an exposure correction must be made. At most working distances, this correction factor is so small that it can be ignored. However, when working at very close distances, it becomes significant and can result in serious exposure errors if not corrected for.
This exposure variance is commonly called extension factor or bellows factor. The Enlarging Attachment will help eliminate guesswork in darkroom printing. It determines contrast range and correct exposure time by measuring the projected Image on your enlarger easel. After calibrations for paper speed, direct readings of aperture and expo sure times are possible, resulting in savings of time and material. The Microscope Attachment utilizes the Luna-Pro F measuring sensitivity for convenient and reliable exposure measurement when taking photomicrographs.
The Microscope attachment fits the ocular tube of most microscopes for exact exposure determinations, and is useful in measuring light intensity for fluorescent microscopy. It is especially suitable for macrophotography, ground glass measurements, density measurements on negatives or transparencies, and for luminous density measurements.
The illumination on the copy board can be measured for evenness of various points on the material to be copied. Simply follow the link provided above and you can directly download gossen luna pro digital manual ppt and save it to your computer or else you can also read online through our library.
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