CHAPTER 4
Films and Film Loading
GENERAL COMMENTS
Most black-and-white, color negative, and color transparency films made for medium format cameras are identical to those made for 35 mm cameras. They are also processed in the same fashion. Thus, for those photographers who have previously worked in the smaller format and are changing to medium format, selecting film is simple. In most cases, the film that you would use in the 35 mm camera is also the logical choice in medium format roll film.
Photographers who frequently work in low light situations with lens apertures of f/1.4 or f/2 on their 35 mm cameras may be better off switching to a faster medium format film if such exists. The reason is that medium format lenses are slower, and a faster film will make up for a slower lens. F/2 lenses do exist for some medium format cameras, but for most the maximum aperture of the standard lens is f/2.8 and even slower on the wide angles and telephotos.
Depth of field is another reason for considering a faster medium format film. When covering a certain size area, the magnification in the medium format is higher than on 35 mm. Depth of field is directly related to magnification. The higher the magnification is, the shallower the depth of field at a specific aperture. Covering a 36 mm long subject with a 35 mm camera means 1 (life-size) magnification. To cover the same area on the 6 × 4.5 cm format means a 1.5 magnification requiring an aperture 1 to 2 stops smaller for the same amount of depth of field.
By using 400 ASA film to capture the medium format image, you can achieve the same depth of field as with 100 ASA film in 35 mm, using the same shutter speed in both. This approach can be especially valuable in close-up photography and is usually not a disadvantage especially when considering the difference in the image size.
With the high quality of today’s films, one should not hesitate to use the faster films. The fast films might allow handheld photography where otherwise a tripod would be necessary. More important, faster films allow you to use shorter shutter speeds and thus reduce the possibility of camera shake.
Wedding photographers have started to use 400 ASA color negative films instead of 100 ASA, The faster films also allow them to use a more compact, lighter flash unit.
Generally, however, for optimum sharpness, it is still better to use the slowest film that can do the job and to select the faster ones only when necessary. Slower medium format films tend to have a higher resolution and finer grain, thus producing a sharper image. They are the obvious choice when sharpness is your main goal or when the negative is to be enlarged tremendously or will need extensive cropping.
Switching from slow to fast films and vice versa is greatly simplified in medium format cameras that offer interchangeable magazines. You can load two or three magazines with different films and then switch from one to the other in the middle of a roll. Thus, you are always in the position to use the film that is best for each subject while carrying only one camera. Those interested in experimenting in the darkroom should not overlook many of the films made for special purposes, such as high contrast photography, copying, and photomicrography.
Amateur and Professional Film
Color negative and color transparency films made by the major manufacturers come in an amateur brand and a professional brand with the same or a completely different name. The only difference between the brands is in the aging process of the film. The colors in an undeveloped film are not perfectly stable; they shift somewhat as the film is stored. Professional film is pre-aged at the factory so it produces the correct color when delivered to the store. To remain in this condition, the film must be refrigerated until about an hour before it is used. If the finished roll is not processed immediately after being exposed, it should again be refrigerated, if possible. Professional films are made so that the professional can count on matched colors and exposure from roll to roll.
Amateur film is delivered to the store in a state where it produces the correct color after it has been stored at normal room temperature for four to six months. Manufacturers have found that this is the average time that elapses from the moment the film is made until it is actually used. Amateur films need not be refrigerated, which can be an advantage when you are taking photos while traveling, but the colors in such films will vary somewhat based on the storage time and temperature.
The choice of amateur or professional film may also be determined by the laboratory. “Amateur labs” may not process professional films or medium format films in general.
In addition to camera steadiness, accurate focusing, lens quality, and film flatness, the sharpness of the black-and-white negative is also affected by exposure and development. Overexposure and over-development increase grain size and thus reduce apparent sharpness. A thin negative that has just enough shadow detail makes the sharpest print.
Too little exposure causes loss of shadow detail. In a good print, the lighter subject tones in the shadows must show detail for the picture to look natural.
Contrast is increased by developing longer and reduced by cutting the developing time. This is a helpful control that not only produces very printable negatives, but also may make it unnecessary to have on hand a wide range of different contrast papers. Most or all negatives can have a contrast range that is printable on a standard grade paper regardless of the subject or lighting contrast.
This principle of contrast control is based on the zone system developed by Ansel Adams, which involves exposing for a specific subject area and then developing the film so that other areas have specific density values, and fall into specific zones. Serious fine art black-and-white photographers are advised to study one or some of the books describing black-and-white zone system photography. Using this contrast control requires that all negatives on a roll of film be taken of subjects with similar contrast. The shorter medium format rolls with fewer images (usually 12) have in this respect an advantage over the longer 35 mm rolls with 24 or 36 exposures. Choose a film development time such that normal subjects will match the contrast of medium or grade 2 papers when printed on your own enlarger.
The Photographic Black-and-White Print
Quality black-and-white prints can only be obtained with a clean enlarger lens that is in top condition. Condenser enlargers yield somewhat higher contrast than the diffused light type. Condenser enlargers usually are brighter, so exposure times can be kept reasonably short. This type of enlarger is usually preferred for enlarging medium format negatives, but use the one that best suits the type of work you are doing. Whichever type you choose, make sure that the illumination is even over the entire field. You can test this by making a print without a negative in the enlarger. Focus the lens on the edges of the negative carrier and stop down to your usual printing aperture. Expose the paper so that it develops out to a middle gray. If the test print varies considerably in density over the printed area, the illumination is uneven.
Photographic Print
To maintain the maximum sharpness in the print, consider the quality of the enlarging lens, film flatness in the negative carrier, accurate focusing of the enlarging lens, and steadiness of the enlarger during exposure. Pay special attention to the negative carrier. The larger film area of the negative has a greater tendency to buckle when exposed to heat in the enlarger. The negative may pop, no longer lie flat, or actually buckle and move while the exposure is being made. Using a glass carrier will prevent this, but remember that all glass surfaces must be kept clean.
Print quality is best when the printing paper is exposed so that the print density is just right when the paper has received the full development time. Considerable underdevelopment causes muddy and perhaps uneven image tones that may have an unpleasant, brownish image color. Over-development results in a lack of highlight detail, fog, or stain, or all three.
COLOR NEGATIVE AND COLOR TRANSPARENCY FILM
Color negative films are made in the daylight version only because the majority of amateur and professional images are made in daylight or with an electronic flash, both with the same color temperature. These films can be used under other light sources, tungsten or fluorescent lights, for instance, and without a filter on the lens. The necessary filtration can be employed when the print is being made. I recommend, however, whenever practical, using the necessary filter on the camera when the picture is taken. All images are then reproduced on the film as if you had taken them under the light for which the film was made, and the filter you use is the same as required for daylight color transparency film; thus, you eliminate many problems later in the darkroom.
Using a filter is especially suggested when no people are in the picture. Without flesh tones, the darkroom technician has no idea what the colors should be unless you include an 18 percent gray card or a color chart in at least one of the negatives. Even with people in the picture, correct colors cannot be assured because flesh tones vary from white to black. If nothing else, including a gray card in at least one of the negatives on a roll of film, eliminates future arguments with the laboratory.
Exposure and developing times cannot be varied when you use color negative film, because color negatives need the correct amount of exposure to produce sufficient shadow details.
Mounting Transparencies
Laboratories do not mount medium format slides. This is not really a disadvantage. Most professional slide work is presented to the client most effectively unmounted or mounted on a presentation board. If such slides are to be projected, glass mounting is highly recommended to eliminate popping in the projector.
Projection Quality
The true quality of a slide, 35 mm or medium format, often cannot be enjoyed on the screen because of the somewhat questionable quality of the projectors’ condenser system and the projection lenses.
If you are interested in medium format slide projection, it is worth investigating the quality of a projector before purchasing it, and be prepared to spend quite a bit more than for a 35 mm machine. Buying a projector is a worthwhile investment because medium format slide projection is very effective. Once you have seen your slides presented in a high-quality projector, it is difficult ever to be satisfied with 35 mm slides.
ROLL FILM
120 Roll Film
All medium format cameras—regardless of what image size they produce—can accommodate 120 roll film. The 120 roll film comes in the widest variety of emulsions. With few exceptions, you can find just about every emulsion that is available in 35 mm. Because of its popularity, 120 film is also most readily available in stores—something travelers might want to keep in mind. At the same time, you must be aware that 120 roll film is not as readily available as 35 mm and is usually only sold in professional camera stores. This is especially true for transparency films. I highly recommend that you take enough film on your travels unless you go to large cities with a professional photographic population.
The 120 roll film has a paper backing from beginning to end. The main function of the paper years ago was for the proper film transport. That is why the paper backing has frame numbers printed on it. In the past, the user advanced the film by looking into a window while turning the film advance knob until the next number appeared in the window. In medium format cameras today, the film transport is automatic so the numbers are no longer necessary. As a matter of fact, the paper is no longer necessary, but it is still there.
220 Roll Film
Since modern medium format cameras no longer need the paper backing for spacing, film manufacturers started to spool 120 roll film with paper only at the beginning and end of the roll just to protect the film when loading and unloading in daylight. Leaving out the paper made it possible to put twice as much film on the same film spool, so a spool provides 24 instead of twelve 2 1/4 in. square images; 20 instead of 10 in the 6 × 7 cm format; and 30 or 32 instead of fifteen or sixteen 6 × 4.5 cm images. This new film became known as 220. Photographers who want to cut down on film changing, as in wedding, sports, and stage photography, appreciate the 220 roll film.
The 220 roll film is used mainly by professional photographers. As a result, only the most popular professional films are made in 220, and these films are available only in specialty camera stores that do professional business. If you like to work with different films, you might be better off staying with 120 film, and buying one or two additional magazines or inserts so you can pre-load additional rolls.
Depending on the camera, the use of 220 film instead of 120 may require an adjustment on the film insert, a different film insert, an adjustment on the camera, or a different film magazine. Manufacturers that supply a special 220 magazine feel it is important to adjust the springs and the pressure plate on the film insert to the particular thickness of each film to ensure best possible film flatness. Since perfect film flatness is of utmost importance for achieving the ultimate image quality in the medium format, it is worthwhile to consider this point when selecting a medium format camera system.
Long Roll Film
Longer rolls of 70 mm film can also be used on some medium format cameras with interchangeable film magazines. The 70 mm film is manufactured without perforations and with different types of perforations known as type I and type II. Perforated 70 mm film looks like 35 mm film, with perforations on both sides. Each camera or film magazine is made for a specific type of 70 mm film. Few film types are readily available in 70 mm form, so find out which film types are manufactured in a compatible 70 mm form.
Most 70 mm film magazines are made for use with cassettes, which are built and look like the 35 mm cassettes, except that they are larger. A cassette holds about 15 ft. of standard base film, which provides room for about seventy 2 1/4 in. square images.
The 70 mm cassettes can be loaded into the camera in daylight. Unlike 35 mm film, the 70 mm film moves from the full cassette into an empty cassette on the other side, so the film does not have to be rewound after it has been exposed.
A few popular 70 mm films can be purchased in cassettes, ready to be loaded into the camera, but few 70 mm film types are readily available or even available on special order. Some are available only in longer lengths on spools for home loading into cassettes. The spooling must be done in complete darkness. It can be done by hand, but using a bulk film loader is more convenient.
Some cameras can also take magazines designed for 70 mm film on spools. The advantage is that the spools can hold more film and thus provide more exposures per roll. This advantage is not obtained without some drawbacks: the need for darkroom loading and unloading. Special emulsions for instrumentation, infrared, high-contrast work, copying, duplicating, and some microscope applications that are not available in 120 or 220 can be obtained in 70 mm, but a minimum order quantity is required.
Another consideration you should take into account before deciding on 70 mm film is that only a limited number of professional laboratories are equipped to process all or at least some of the 15 ft. or longer lengths of film without cutting them. But equipment is available for processing the film at home.
SHEET FILM
Magazines for sheet film used to be available for some medium format cameras, but, since they were seldom used, are difficult to find today. Such a magazine is designed and operates like those made for view cameras. The film is inserted in complete darkness into the sheetfilm holder, which is protected by the dark slide. Sheet film does not come in ready-made medium format sizes, so you must cut your own from larger sizes. This need for cutting the film to size is undoubtedly the reason these sheetfilm magazines have been used rarely and only for the use of special films not made in any other form such as orthochromatic black-and-white films or films for spectroscopy or photomicroscopy.
A major advantage for working in the medium format is the possibility of attaching a Polaroid instant film magazine at any time to a camera with interchangeable film magazines. Other film magazines can provide the option of using different film types or producing images in different formats.
INSTANT FILM
Instant films can be used on a number of medium format cameras. Camera manufacturers have introduced this possibility not to provide the medium format photographer with an instant snapshot camera, but so that serious amateur and professional photographers can see on a print the image actually recorded through the lens. Just as videotape allows an athlete to study his motions instantly or an audio tape allows a musician an instant test of sound quality and effectiveness, an instant print is the most reliable assurance you can have that the camera is functioning properly, that the lens and camera settings are correct, that the flash is synchronized with the shutter, and that you are using the correct accessories. Instant film allows you to experiment without guessing and to make changes before the shooting starts. It eliminates guesswork, and saves on film and laboratory costs, and it also serves as an excellent teaching tool since it allows the student to see instantly the results of the teacher’s approach. Professionals may want to use instant film to show the print to clients to determine whether the image is what was expected and to get instant approval.
Exposure Testing
Checking that exposure is correct is another, and often the most important, application for instant film. It is especially useful under unusual lighting situations or when you are combining different light sources. When you use Polaroid film for checking exposure, keep in mind the type of film you will be shooting. Transparency films must be exposed for the lighted areas, negative films for the shade. The lens settings are thus correct for slide film when the Polaroid test shot is properly exposed in the lighted areas. They are correct for negative film when the test shot has shadow detail.
Checking Light Ratios
In multiple flash setups, you can use instant film to check the effectiveness of the lighting, how and where shadows fall on the subject and the background, and to detect possible disturbing highlights. When you are combining light from different light sources, flash fill-in, for instance, Polaroid shots become still more valuable. An instant picture is a must for determining exposure as well as the effectiveness and evenness of the lighting when you are painting with light.
Effects of Shutter Speeds
There is no way you can see with your eyes or in the viewfinder how the shutter speed will affect or change the image of a moving subject. If you want to stop action, you can follow written guidelines, but there are no strict instructions for those instances when you want to record the moving subject with a blur to enhance the feeling of motion.
Make a test on instant picture film at one shutter speed. If the results are not satisfactory, shorten or lengthen the shutter speed to get more or less blur, and repeat the process until the instant picture shows exactly the desired results.
It is a good idea to make a test using instant film when you plan to move the camera to produce the blur; when you want to change the focal length of a zoom lens while the shutter is open to produce a zoom effect; when you use vignettes, or other accessories in front of the lens, or when you are combining electronic flash with slow shutter speeds.
Instant film allows you to evaluate effects that cannot be seen on the focusing screen, such as the amount of blur produced by moving the camera in combination with a slow shutter speed.
As a Teaching Tool
Instant film material helps give others immediate visual proof of what you are shooting. This can be for the purpose of immediately showing photography students the result of a photographic approach under discussion, or for showing a model’s performance in front of the camera. Instant film material allows an entire group to see things that normally can be seen by only one person, such as the view through a microscope.
Adjusting for Film Sensitivities
In the majority of cases, the negative or transparency film used for your final image will have a different exposure index than the instant film material used for the test. Thus, for correct exposure, something must be adjusted. The following adjustments are possible:
1. Change the shutter speed. Do this only when the shutter speed is not a deciding factor for creating the image. For blurred motion effects, the same shutter speeds must be used.
2. Change the aperture. I recommend this course of action when the shutter speed cannot be changed and/or when depth of field is not the deciding factor.
3. Use a neutral density filter either when making the test shots or when making the final shot. Depending which film has the higher sensitivity, using such filters allows you to make identical lens settings with any combination of films.
The amount of correction necessary is shown on the chart below, which is based on an instant film sensitivity of 100 ASA, 21 DIN, the most common film used for test shots.
EXPOSURE CORRECTIONS FOR FINAL FILM BASED ON 100 ASA POLAROID
Final Film |
Multiply |
|||
ASA |
DIN |
Change in |
Use Neutral |
|
50 |
18 |
Open 1 stop |
2× |
0.30 with instant film |
64 |
19 |
Open 1/2 stop |
1.5× |
0.10 with instant film |
100 |
21 |
None |
1× |
None |
160 |
23 |
Close 1/2 stop |
1× |
0.10 with final film |
200 |
24 |
Close 1 stop |
1/2× |
0.30 with final film |
400 |
27 |
Close 2 stops |
1/4× |
0.60 with final film |
800 |
30 |
Close 3 stops |
1/8× |
0.90 with final film |
Shutter speeds are multiplied as follows:
Original shutter speed 1/125 second
2× = 1/125 × 2 = 2/125 = 1/60 second
1/2×: 1/125 × 1/2 = 1/250 second
Polaroid Film Magazine
The instant film image is obtained by attaching a Polaroid magazine to the camera; regular Polaroid film packs are used. It should be possible to switch magazines at any time, even in the middle of a roll of film. The sheet of instant film is larger than the image produced by the medium format camera so you waste some film, but the image and image size are the same as recorded on the roll film, and that is more important. Follow the instructions on the instant film pack regarding the use, storage, and developing of the film.
FILM LOADING
Roll Film Loading
The 120 and 220 roll films are sold on spools. On the majority of medium format cameras, the film is loaded on a separate insert, which is inserted into the camera or a film magazine. The spool with the unexposed film goes on the feed reel, and the beginning of the film is attached to an empty take-up spool. Roll film need not be rewound on the original spool as in 35 mm, so changing film is quite fast.
The film insert with the loaded film may go into a removable film magazine or directly into the camera body. The latter allows you to pre-load several inserts before going on a job. Changing film then involves only switching inserts. Inserts are less expensive than film magazines, but do not give you the opportunity to change film mid-roll or to attach a Polaroid magazine. The danger of fogging film is also greatly increased. If you want to take full advantage of the film changing possibility, you must consider loading the film into a completely interchangeable film magazine and forget about interchangeable film inserts.
On some cameras, the film moves from reel to reel in its natural curl, as rolled on the spool; on others, it moves in an inverse curl. It has been mentioned occasionally that inverse film movement reduces film flatness. Film flatness, however, is a matter of a properly designed pressure plate and magazine. I have never seen proof that the natural curl results in better film flatness and thus better sharpness, so I must assume that testimonials about natural curl are nothing more than an advertising strategy. However, regardless of how the film is spooled, the second image on a roll of film that has been left in the camera for some time may show a loss of flatness. If you plan to leave a film in the camera, advance the film just before you take the next image.
Roll film must be advanced to a certain point to ensure proper spacing. With 120 and 220 films, the thick arrow on the paper is set opposite an index engraved on the film insert before the insert goes into the camera or magazine. Some 220 films have a dotted line on the paper backing before the black arrow. Do not put the dotted line opposite the index. You will lose the first two frames. Move the film further to the black arrow.
On most film magazines and cameras, the arrow on the roll film must be set opposite an index on the roll film holder. Do not set the dotted line on some 220 films opposite the index.
Before a picture can be made, the paper leader must be moved through the camera. On older cameras, the film had to be wound to 1 by watching the paper through a window and turning the crank until 1 appeared in the window. On newer cameras and magazines, you simply turn the crank until it stops. The beginning of the actual film is now behind the aperture, and spacing between the images should be fairly even from here on. Spacing refers to the blank space between the frames. On some cameras designed for the 6 × 4.5 cm format, however, the space between frames changes, which is the reason you can obtain only 15 images instead of 16 on a roll of 120 film. On a well-designed camera or magazine, the space may vary somewhat, but it should never vary so much that the last image falls into the paper trailer, and there should always be sufficient space between images to cut the film.
While loading is simple, a few suggestions need to be made. Always completely remove the paper that holds the film tight on the spool; otherwise it may become loose and wedged in the film aperture and act like a mask in front of the film. Although roll film is designed to be loaded in daylight, do not load it in bright sunlight. Keep the film in the shade and tight on the spool during the entire process; otherwise light can fog the edges. Practice so you can load quickly without exposing the film to daylight longer than is necessary. After the last picture on a roll is taken, you must wind up the paper trailer before removing the film. The now empty feed spool becomes the take-up spool for the next roll of film.
Film Magazines
Cameras with interchangeable magazines are likely to be more expensive because they require a greater precision so every magazine fits perfectly on every camera and couples to the camera mechanism as if it were part of the camera itself. But the versatility of such cameras, allowing you to do things with one camera that otherwise require two or three cameras, may well be worth the additional cost.
Before removing a loaded film magazine from the camera, you must insert a dark slide so the film is not exposed to light. The purpose of a dark slide is the same as the dark slide in a sheetfilm holder of a view camera: to protect the film when the magazine is off the camera. It serves no purpose as long as the magazine is attached to the camera. Well, not quite. On most cameras you cannot depress the release until the dark slide is removed, at least partially. Thus the dark slide can be used to prevent accidental releasing.
Rotatable Film Magazines
Most medium format cameras made for rectangular pictures must be turned for verticals just like 35s. Another solution in the medium format is a rotatable film magazine; the film magazine, not the camera, is rotated for verticals. Such a design is a convenience, especially when you are working on a tripod, but to accommodate this magazine, the camera body needs to be considerably larger—at least as wide as the long side of the negative in either direction—so what you gain in versatility you may lose in convenience.
OPERATING SIGNALS
Medium format cameras, especially those offering interchangeable film magazines, should have operating signals and controls to prevent mistakes, and to make it unnecessary for the photographer to do a lot of worrying while shooting. A frame counter that shows the number of exposed pictures is taken for granted. Most frame counters are coupled to the gears and work whether there is film in a camera or not. The camera or the film magazine should have a signal that shows whether there is film in the camera or magazine. The signal must work whether the magazine is on or off the camera, and to be reliable, the signal must be controlled by the film itself, not the mechanism in the magazine.
The camera or magazine should have a place where you can make a notation of the type of film you are using and its ASA rating. Furthermore, there should be a signal that indicates whether the film is advanced, and this signal must work with the magazine on or off the camera. The camera should also have some arrangement whereby the release cannot be depressed after you have exposed the last frame. This warning should preferably come right after you have shot the last frame, rather than when you try to depress the release again.
Unless you use the same film all the time, always indicate what film is in the camera or magazine.