MONOPHOTO FILM SETTING MACHINE

[Music] [Music] Have you seen this before? Well, something like it perhaps in black and white. It's a pleasantly unpleasant little story that appeared as an inset in the 1957 Penrose annual. But its interest for us lies not so much in its contents as in why and how it got there. Why? because it's a typical example of photo lio printing the text of which was set on a monooto film seta made by the monotype corporation limited. Now that's a rather longer story but thanks to this film I think you'll find it an interesting one. Copy comes to the keyboard operator with a layout and instructions for style according to which he has made the necessary adjustment of his machine. Now with copy where he can best read it, the keyboard operator gets on with the business of tapping. Can you see the difference between the technique he's using and what he'd be doing for hot metal composition? No, it's exactly the same. And the keyboard's the same, too, except for one or two slight modifications. What you can set for a monotype composition caster, you can set just as easily for a monooto film set. So the operator transfers the copy to the paper ribbon, a spool of which will conveniently carry several hundred words. automation. In fact, it's become a fashionable word lately, but we'd like you to remember that it's been a feature of monotype working for the past 60 years. Obviously, it took rather longer than that to tap out our story, but as you see, there's nothing unusual about this preliminary part of the process. Here are our perforated spools. We fit them to a monopoto film set for transformation into a photographic film in which the characters the typographical characters that is not the people in the story will appear in the exact size required for printing and ranged correctly in fully justified lines. A monopoto film setter is obviously first cousin to a monotype composition caster. Many of the features are identical in fact interchangeable and much of the operating principle is the same. The paper tower is the same and the spool has been fitted in the usual way. I'll show you presently how the machine has been set up according to the instructions on the spool label. Starting the machine entails all the labor of pressing one switch and turning another. Running speed is 10 to 12,000 ends an hour. The operator's gone off confident that all will be well till the end of the spool, provided that he occasionally checks that the machine hasn't been automatically stopped by interruption of the air supply or an electrical circuit. Meanwhile, what's going on inside? Let's start off with a diagram to follow the theory before seeing its application. Here is the source of light. It shines through a condenser lens to give equal light distribution all over the character in the film matrix case selected by mechanical action controlled from the paper ribbon. Then the light travels through an optical wedge which can be adjusted for each size of image. Its angle ensures that whatever size or fountain is being used, the first image in every line shall fall in exactly the right place. Theoretically, the beam of light then goes through the projection lens to produce a focused image. But in order to save space and to give an easy way of focusing to produce different sizes of image from a single matrix, we fold up the light beam by passing it through a pair of reflecting prisms rather on the principle used in binoculars. So far, even though we changed the position of the master negative assembly to project the succeeding character, we shall still get its image in the same position. And the film would simply register this as the double exposure that haunts the amateur photographer. So to put the second image beside the first, we use a pair of mirrors which after each exposure move a distance governed by the width of the character projected. Now let's look at the machine again. The source of light that's here. It's switched on all the time the machine is running and the individual exposures are made by the shutter just below it. The prisms and projection lens are housed in this prism box which is of course light proof and keeps out the dust. The traveling mirrors are inside this casing and throw the image up onto the film carried by a drum in here. So much for the general scheme of things. Now perhaps you'd like to see how it's really done. Anyway, that's what we're going to show next. Let's start off with the film matrix case. Just the same sort of thing as the matrix case of a monotype caster. And when in the machine moved in exactly the same way, but instead of the punched metal mattresses, we have 255 characters transparent against an opaque background and arranged in unit rows as they would be in a matrix case. Each negative gives a range of several image sizes variable by lens adjustment. As you'll see in a minute or two, each of the film characters is contained in a separate casing which serves both to protect it and to make it easy to handle. If any odd sorts have to be used, it's quite easy to affect the changeover. So, the film setter is just as flexible in application as a hot metal caster. A special type of spring forceps is inserted in the casing, allowed to expand, and withdrawn, extracting that character to make room for the replacement. This is picked up in the same way and inserted in the space. A vacuum cleaner is then used to extract those tiny particles of dust which however carefully the job is done have settled on the mattresses during the operation. And then the transparent cover, the same way up and the same position as before, is replaced at once. The retaining grid follows and eight screws secure it. This arrangement keeps all the film mattresses in position and prevents any more dirt getting in. Now we put the film matrix case into its carrier. Punch a couple of perforations into a bit of paper ribbon and turning the machine slowly by hand show you how standard monotype mechanism brings the corresponding character into its operational position. It's held there by the usual locking arrangements. The lamp you will remember is up here housed in a ventilated turret. It's simply a prefocus 48 W projection lamp and just below it is the condenser lens. Then comes the film matrix case followed by the shutter. This is worked from the cam lever that looks after the tight carrier of a caster but of course with special timing. The shutter has a variable opening to compensate for differing film speeds but not for variations in machine speed as this is constant whatever the image size. You see there's no cooling of molten metal to consider. Inside the prism box, we find at the top the optical wedge with its setting dial. Then the first prism and the second prism and then the projection lens. The light then goes down through an aperture automatically light sealed whenever the door is opened and so to the first of the inclined mirrors. Both mirrors are rigidly fixed to the same traveling bar and the second mirror throws the beam up to the film on its drum where it is focused. To make the action a little clearer, let's have another diagram. Here, a chain represents the path of the light from the projection lens down to the first mirror, across to the second, and so up to the film. Now, as the mirror bar moves, so the light strikes lower down the first mirror, across a narrower gap to the second, and up a longer path to the film, but the total length of the chain is unvaried, even though it's reaching only to the near side of the film. With the mirrors at 45° to the path of the light, this is a natural phenomenon for which we are very grateful to Mr. Uklid. Back on the machine, it's easy enough to move the inclined mirrors along as they are mounted as a unit on the mirror bar. The problem is to shift this after each exposure just the right amount for either a character or a space. This is all done with great precision by an assembly of racks and gears, which takes the place of wedge operation. First, let's look at the unit rack. This takes the place of the normal wedge and advances and retires in step with the film matrix case. Its movement rotates this pinion mounted on a lay shaft at the other end of which is a helical gear to give motion to the unit selector. This therefore turns carrying the unit selector to the position of the required unit value. This turning brings into an operative position one of the lugs which finally determine the amount of drive to be given to the set gears. These convert it into a movement representing so many units of the set of the face concerned. The movement is fed back into a shaft running along inside the gearbox where by means of differential gears, it governs the rotation of a vertical shaft that drives through an electromagnetic clutch, a pinion that meshes with the mirror bar rack. It's an interesting mechanism and quite logical, but frankly, I don't think anybody can be expected to pick it all up in the few minutes we have available. I'll just say that the principle of the justification racks is very much the same. This is the coarse justification rack and its pinion carried by a tubular shaft enclosing the lay shaft and passing its movement through this helical gear. The fine justification rack meshes with this pinion and here are the respective selectors. They do more strange things among the differentials and give an output which is accepted as space justification not only by the mer but by many competent typographical critics as well. Now let's look at something a bit simpler for a change. Above the casing in which the inclined mirrors travel is a slot covered either by this dust shield or by the film box containing the drum on which the film is laid. This has a slot at the bottom corresponding to the one on the machine so that the light from the left hand mirror can come up anywhere along the slot to its focus on the surface of the film. As the mirrors move along, so the successive images are projected in perfect alignment across the film. To prevent light leaking in through the bottom of the film box when it's not in its working position, an air gap shutter attached to the drum covers the slot. Its position is shown on this scale which also indicates how much film has been used. There's also this second wheel with its scale graduated in half points giving scope for very accurate positioning when the drum has to be reset for adding a dropped initial or making any other interpolation in the normal setting. When a line has been completed, the mirror bar and mirrors return automatically to their starting position and carry on with the next line as the feed rack has at the same time turned the drum forward by the required amount. This may be preset for the distance needed for solid text or for any smaller or greater distance in halfoint steps up to 24 point to give the effect of leaded type. Accuracy of alignment is maintained by holding the drum with a lock rack all the time the images are being recorded on the film and only releasing it after the feed rack has been engaged. The line feed is basically governed by the point size of the characters. So it's one of the five sections of the machine that need resetting when changing over from one size and face to another. Suppose we've been running time 6 point and the next film calls for grotesque 24 point. To give the correct distance from the base of one line to the base of the next, this indicator is moved from six point to 24 point. That alters the effective length of the feed stroke. Now on the other side of the machine, the set gear is changed to increase the stride of the mirror bar to suit the wider characters, thus giving instantaneous sizing. The optical system has to be rearranged to give greater magnification. So the lens is swung from one side to the other and a fresh set of focusing bars is substituted. These shorten the distance between matrix and lens and increase the distance between lens and film. There's no need for obstruuse calculations. You see, we've done that already. To change the film matrix case is just as easy as it is to change a hot metal matrix case. Finally, we may have to do what very roughly corresponds to changing the normal wedge, and that is the substituting of the appropriate unit selector assembly if necessary. The operative would have one already paired with the matrix case, as a new arrangement can easily be built up to suit any particular unit aortionment. Oh, and while we're dealing with the subject of setting up, I'd just like you to notice the adjustable stop on the mirror bar. It can be fixed wherever it's wanted for multicolumn work, which as these examples show, can be well done on this machine. If necessary, you can easily check up on the functions of different sections of the machine by using the selective electrical controls grouped on the panel above the hand wheel. Motor, lamp, and clutch can be operated independently or in various combinations as required. Main switch and fuses are part of the electrical system. This also includes the safety switches. You see what happens if anything upsets the air supply. There's a sudden silence which brings the operative to investigate. When that's put right, perhaps you'll show us what happens as a result of the projection lamp circuit failing. The same thing. Those were precautionary stops. Here's the routine stop at the end of the spool. Now the film has to be processed. First of all, the air gap shutter on the drum must be brought down to the bottom to light seal the box. There's the dust cover replaced. And now we go off to the dark room. Here the box is opened and the film extracted ready for the usual photographic procedure of development and fixing, washing and drying. While this is going on, a new film cut to the length and width required is positioned on the drum for the next job. It's very important that this should be done carefully with the film registering exactly to the stop pin at its base and the flange of the drum on the right. Having got it there and made sure there are no wrinkles, we fasten it in position with adhesive tape, replace the cover and bring the air gap shutter back to close the slot. Now that's done. Now our film's ready for the making of a photographic print to be treated as a proof. This is a reverse reading film positive. It's possible to produce instead an original that is any combination of the terms direct or reverse reading, positive or negative, paper or film, all from the same keyboard spool. Incidentally, the terms direct reading and reverse reading are always used in reference to examination of the film or paper from the emulsion side. The corrected proof corrections will be with us just so long as authors and keyboard operators remain human and some of them are terribly human. The lines affected are treated as new copy keyboarded filmed on stripping film proofed and checked by means of this device which enables the operator to do it with great accuracy. The error lines are then stripped out of our main film and replacements from the correction film are substituted. Accessories are provided for each point size. First, the correction film is located on the table flush with the abutment flange. The table is accurately positioned with the slot in the bridge exactly over the first of the lines to be extracted and the cutting tool is likely drawn across first the top and then the bottom of the line. Then the upper part of the bridge is moved away and at a little distance from the ends of the line, vertical cuts are made to isolate it and a corner of the stripping membrane is lifted. A transfer strip tacky on the underface is now carefully put over the line with its fore edge registered by the setting bar and the left hand end just touching the abutment flange. It is pressed down and then gently raised bringing with it the correction line. Then a smear of thin adhesive for the reverse of the membrane. Other lines are lifted in the same way and can be filed in the correct order for insertion in the main film. The main film then goes down on the table in the same way properly aligned and the first error line is brought under the slot. The other end of the tool enables the imulsion of ordinary film or the membrane of stripping film to be eliminated by a single stroke. Now we can dispense with the upper part of the bridge again and bring in our correction line still attached to its transfer strip. This is positioned exactly as it was before just touching its locating guides. It is pressed down and then withdrawn leaving the correction line accurately substituted for the faulty one. The table can now be advanced and all the other correction lines inserted in the same way. And there with the completed and corrected film, the film setup part of the job is finished. The rest is concerned with other sections of the printer's craft. Copies are quickly run off. And but this is where you came in, isn't it? You've seen our method, the monotype method of film setting and one of its products. The effective range of work has not yet had its limits determined, but we do know they will be wide. for complicated work such as Hebrew and Arabic texts and even printed circuits presents no difficulties. Film setting is a relatively new technique. His most efficient applications in the world of print await definition. But we are convinced that a monopho film setter clearly represents a notable stage in the development of that technique and that it is already well on its way to occupying the prominent position that it is destined to hold. I think that you'll be inclined to agree. [Music]