Microfilm

“ Since POB is using microfilm, it is not concerned with the image library as a preservation medium. 2) Digital imagery can improve access to recorded knowledge through printing and network distribution at a modest incremental cost of microfilm. 3) Capturing and storing documents in a digital image form is necessary to further improvements in access. (POB distinguishes between the imaging, digitizing process and OCR, which at this stage it does not plan to perform.) ”

“ At least two major new historical editing projects are considering microfilm editions, simply because they are not aware of the possibilities of electronic alternatives and the advantages of the new technology in terms of flexibility and research potential compared to microfilm. In fact, too many of us in history and literature are still at the stage of struggling with our PCs. ”

“ The resolution of key issues such as the quality of scanning and image browsing also will affect development of that market.
The technology is readily available but changing rapidly. In this context of rapid change, several factors affect quality and cost, to which POB intends to pay particular attention, for example, the various levels of resolution that can be achieved. POB believes it can bring resolution up to 600 dpi, but an interpolation process from 400 to 600 is more likely. The variation quality in microfilm will prove to be a highly important factor. ”

“ Saving the intellectual content of the material is the main goal. With microfilm copy, the intellectual content is preserved on the assumption that in the future the image can be reformatted in any other way that then exists.
An underlying assumption of the CLASS Project from the beginning was that it would develop a network application. Project staff scan books at a workstation located in the library, near the brittle material. An image-server filing system is located at a distance from that workstation, and a printer is located in another building. ”

“ PS. If bots start hitting on you, you know they're getting close to taking over the world. I for one welcome our robot overlords! :) Xover (talk) 18:20, 16 May 2022 (UTC) Potential workflow for scanned microfilm documents I ask this question here, rather than on Scan Lab, because I think you might be able to set up a process—but I’m not sure, so I’ll get to the point. I have scanned in some documents on microfilm, but they need to be processed before they can be uploaded. ”

“ The History Department at the Fort would be most interested in that, but the only thing that interested Altamont was the statement that the floor had been laid over the trapdoor leading to the vaults where the microfilms were stored. He went outside to the radio.
"Hello, Jim. We're inside, but the films are stored in an underground vault, and we have to tear up a concrete floor," he said. "Go back to the village and gather up all the men you can carry, and tools. Hammers and picks and short steel bars. ”

“ For micro-photography the following practical rules must be observed. The sub-stage condenser may be dispensed with when low powers are used, as well as the mirror, and the lamp so placed that the image of the flat of the flame appears accurately adjusted in the centre of the field of the microscope. The bull’s-eye lens is so interposed, that the image of the flame disappears, and the whole field becomes equally illuminated with high powers; the sub-stage achromatic condenser must be used, and a greater intensity of illumination is obtained by placing the lamp-flame edgeways. ”

“ The greatest delicacy in manipulation is necessary, as in working with a 1⁄12-inch objective a turn too much of the fine adjustment will cause the image to vanish. With fine preparations of bacteria it is not easy to trace the image, and hence the advantage of commencing with a well-marked object, as that of the fly’s tongue. The development and fixation of the image must be proceeded with as in the ordinary photographic process. In the text-books of photography full accounts of failures will be found, their causes and prevention. ”

“ A micro-organism, even under the highest powers of the microscope, is so minute an object, that to represent it in a drawing requires a very delicate touch, and it is only too easy to make a picture which gives an erroneous impression to those who have not seen the original. Photography enables the scientific worker to record rapid changes, and it is quite possible as the art advances we may find the film more sensitive than the human retina, and that it will bring out details in bacteria which would be otherwise unrecognised. ”

“ I might explain, briefly, that moving pictures are taken not by pressing a switch, or a rubber bulb, such as that which works a camera shutter, but by the continuous action of a crank, or handle, attached to the camera. Pressing a bulb does well enough for taking a single picture, but when a series, on a long celluloid strip, are needed, as in the case for the "movies," an entirely different arrangement becomes absolutely necessary.
The sensitive celluloid film must move continuously, in a somewhat jerky fashion, inside the dark light-tight camera, and behind the lens. ”

“ Every micrographer has his own views as to the form of an installation to be adopted, and it will therefore be well to give an illustration of a definite apparatus which has been found to give satisfactory results. It consists of a microscope A with a firm base placed in a horizontal position. The microscope can be connected by a tube B with the expanded camera CC, at the end of which is the usual frame to receive the photographic plate. A practised observer can focus on a plate of clear glass by the aid of a subsidiary low-power microscope lens. ”

“ Home-Made Motion-Picture Camera and Projector In Three Parts—Part II Developing
After having exposed the film in the camera, the next steps are to develop and make a positive film from the negative. The developing and exposing of the film for the positive are the same as in ordinary photography for making negatives and lantern slides, the only difference being in the apparatus for handling the long films. One of the simplest ways of developing a long film is to use a large tray in connection with a cross arm having upright pins around which the film is wrapped in a continuous spiral. ”

“ Some persons employ a large film, mounted in this way between the plates of glass, with a raised edge, to act as a stage for supporting the object, it is then called the “selenite stage.” The best film for the microscope is that which gives blue, and its complementary colour yellow. The late Mr. Darker constructed a selenite stage for the purpose (Fig. 182) . With this a mixture of colours will be brought about, by superimposing three films, one on the other. By slight variations in their positions, produced by means of an endless-screw motion, all the colours of the spectrum can be shown. ”

“ Fireproof films are probably one of the most important developments in the whole great motion-picture industry, for through these, schools, colleges, churches, lecture halls, and other public places not fitted with the fireproof box in which the motion-picture 174 operator works, can have the advantage of cinematography.
It was a difficult matter to find a non-inflammable film, for science has not yet discovered a base that can be made without cellulose, but the base we know to-day was treated so as to be non-explosive and practically non-inflammable. ”

“ In practice positive printing is done by a machine using for its essential principles the shutter and feeding devices that we have seen in the motion-picture camera. Negative and positive stock are perforated alike, and when superimposed the perforations fall in alignment. The film-feeding device of the printer engages in these perforations just as we saw it do in the camera, only in this case it is moving the negative and positive film along simultaneously. What would be the lens in the camera is here the place where the light is allowed to pass through. ”

“ It is simply developing on a grand scale, thousands of separate pictures on hundreds of feet of film being developed at once.
A negative, however, is of no use unless a positive or print of some kind is made from it. If shown through a stereopticon, for instance, a negative would make all the shadows on the screen appear lights, and vice versa. A positive, therefore, is made by running a fresh film, with the negative, through a machine very much like the moving-picture camera. ”

“ The production of high-power photo-micrographs, as the pictures of highly magnified objects are called, can only be carried out by those who are skilled in the use of both camera and microscope and are possessed of considerable patience. There is nothing to prevent any amateur photographer who possesses a bellows camera—box cameras cannot be used for this work—from producing excellent low-power photo-micrographs, that is to say pictures of objects less highly magnified. ”

“ A moving-picture machine is really a rapid-fire repeating camera provided with a lens allowing of a very quick exposure. Internal mechanism, operated by a hand-crank or electric motor, moves the unexposed film into position behind the lens and also opens and closes the shutter at just the proper moment. The same machinery feeds down a fresh section of the ribbon-like film into position and coils the exposed portion in a dark box, just as the film of a kodak is rolled off one spool and, after exposure, is wound up on another. ”

“ Future work will build upon the key features of this platform. Roll-to-roll processing of flat components and automated “print-and-fold” assembly make yearly outputs of a billion units attainable. Ongoing work with advanced micro-optics and illumination design ― including spherical GRIN lenses [26] – [27] , aspheric multi-lens optics, and condenser lens provisions for Köhler illumination ― is expected to improve both resolution and field of view at low cost. International field-work in both diagnostics and education will provide vital inputs for further improvements. ”

“ A camera, then, consists of a light-tight box having at one end an arrangement for holding a lens or a card with a needle-hole in it, and at the other end a device for holding some light-sensitive chemical to receive the image projected by the lens. In modern practice this light-sensitive chemical is almost always bromide of silver or a mixture of the bromide with other silver compounds, these chemicals being held in an emulsion of gelatine. When the gelatine emulsion is coated in a thin film on a sheet of glass the result is known as a dry-plate, or, simply, a plate. ”

“ A correspondent of Camera Craft makes proofs from his developed, but unfixed, negatives, by squeezing a sheet of wet bromide paper into contact with the wet film and giving an exposure several times longer than would be required under ordinary conditions, using the paper dry. If the developer is well rinsed out of the film, the exposure to artificial light necessary to make a print will have no injurious effect upon the negative, which is, of course, later fixed and washed as usual. ”

“ Apparatus and Material used in micro-photography have, from time to time, been greatly varied by different workers, some preferring to use the microscope in the vertical position with the camera superimposed or fitted on the eye-piece of the microscope tube; others, again, prefer that both the microscope and the camera should be 213 arrayed horizontally. In another form the ordinary microscope is dispensed with and the objective stage and mirror are adapted to the front of the camera, together with a suitable arrangement for holding the object. ”

“ Dispensing with levers, the screw alone is used for rougher work. Dr. Shaw has shown that one hundred-thousandth of an inch is the smallest dimension visible under a microscope. By fitting an electric measuring apparatus to the microscope carriage it becomes quite easy to measure minute distances. The microscope contains a cross wire which, when the object has been laid on the microscope stage, is centred on one side of the object. The electric contact screw is then advanced till it makes contact with the stage and a sound arises in the telephone. ”

“ The silver bromide in the emulsion is affected only by those rays which are stopped, so that the energy of the rays which pass through the emulsion is wasted. If a plate is coated with a very thick film, a larger proportion of the rays can be stopped, and many X-ray plates differ from photographic plates only in the thickness of the emulsion. A thick film however is undesirable because it makes the after processes of developing, fixing, and washing very prolonged. ”

“ We have now manufactured and sold over 71000 compound microscopes and 31000 oil immersion objectives, a large number of which are used in the laboratories of Universities, Colleges, and other Educational Institutions of the United States.
We are prepared at New-York and Chicago to repair our instruments or make alterations at short notice and at lowest prices. The optical part of a microscope should invariably be sent to the maker, as he is best in a position to repair same and has an added interest to bring a lens back to its original quality or even improve it. ”

“ The bleached gelatine plate (which of course must be of proper size to fit the holder) is to be placed therein with the film side p230 toward the microscope. Now place a focussing glass against the back of the plate, apply the eye to it and adjust the focus by a delicate pull of the cord. Nothing can be more satisfactory. When the proper adjustment is determined upon, secure it from possible change during exposure, by winding the cord once or twice over the screw eye at the rear of the camera frame. ”