PhotoHistory

From: Complete Self-Instructing Library of Practical Photography
Volume I - Elementary Photography

The Camera How to Operate It

By J. B. Schriever, 1909

Focusing

Focusing a camera means the act of bringing the image into focus; i.e., the securing of a clear, sharp outline of the image upon the sensitized plate or film. The focus is secured by moving the lens a certain distance from the ground-glass or focusing screen. This distance depends upon the focal length of the lens employed.

Fixed Focus

This term applies chiefly to small box cameras or to those fitted with short focus single lenses. It does not mean any distinct kind of a lens with extraordinary power of covering objects near or far in one plane. The lens is only a fixed focus when it is immovable. While any lens can, practically speaking, be made a fixed focus, yet its length of focus determines the extent it will focus sharp all objects on one plane. Therefore, those only of very short focus can be used for this purpose, and only small pictures are satisfactorily made with fixed focus cameras. With them, the difference in focus of any object, far or near, is so little that it is not noticeable in the picture. On the larger sizes, however, it would be quite visible. There is no altering of the focus in a fixed focus box camera; the lens in the camera is stationary.

Fixed Focus Folding Camera

In the case of the fixed focus bellows camera, the bellows extends to its full length and locks. It is then, practically speaking, a fixed focus camera, the same as a box camera, for there is no adjusting of the bellows. Hence the term, fixed focus folding camera.

Universal Focus

The term Universal Focus is quite frequently applied to adjustable focusing cameras. We speak of the Universal Focus when the pointer is set at 100 feet on the focusing scale. All objects beyond this distance are in focus. When, therefore, the bellows of the camera is extended and the indicator points at 100, we speak of setting it at Universal Focus, or point of infinity.

Extending the Bellows for Focusing

By turning the lever or pressing the clamp directly beneath the lens at the base of the camera front, you release the lock, and the bellows can be drawn forward on the track or slide provided for this purpose. It is by sliding the bellows backward and forward, bringing the lens closer to or extending farther away from the ground-glass, that the focus is produced.

Scale Focusing

Observe on the left side of the camera a scale usually marked No. 6-10-15-25-50-100. These figures indicate the distance the camera should be placed from the object to be photographed. No. 6 would indicate that the camera must be six feet away from the object in order to have it in focus. The pointer being placed at No. 25 would indicate that when the camera is twenty-five feet from the object it would be in focus. It is safe when distances are over 50 feet to set the point of the indicator at 100, as this then becomes, practically, Universal Focus.

Ground-Glass Focusing

By focusing is meant, as stated above, the obtaining of good, clear outlines of the image, on the ground-glass, of any object being photographed. This focus is obtained by the racking, or drawing out of the bellows until the image appears perfectly sharp on all parts of the ground-glass. When the camera is used without a tripod, the focusing scale on the side of the camera bed is employed and the pointer is set on the line opposite the figures, indicating the distance between the camera and object, which should give a perfect focus. It is not advisable to alter the camera in any particular until thoroughly familiar with all its parts. To detect any error in the focusing scale, should your pictures be out of focus (i.e., not sharp), study the following instructions and learn how to correct the fault. Again, the proving of the focus is also a very good practice, for one cannot become too well acquainted with his instrument.

Testing the Focus

In order to test the focus select a building or object in strong sunlight. Determine the distance this object or building is from the camera, which distance, in order to obtain good drawing, should be sufficient to allow the image not to appear crowded on the finder. Then, set the pointer on the camera to the corresponding number of feet on the scale attached to the camera bed, which should give a sharp focus.

After pressing the bulb the first time and opening the shutter, point the camera at the object upon which the sun is shining. Look on the ground-glass and carefully examine the image. If this image appears clear, sharp and distinct, the scale on the side of the camera is correct. If it is indistinct, and the distance from the object has not been misjudged, the scale is incorrect and cannot be relied upon. These scales, however, are usually correct, but in order to test them properly the camera must be placed upon something rigid, a tripod preferred.

Cover the head and camera with the focusing cloth. With the left hand gather the focusing cloth up under the chin. This will then exclude all light except that which comes through the lens and produces the image on the ground-glass. Look on the ground-glass. Do not try to look through it. It will take a little practice to enable the beginner to see the image clearly on the ground-glass. The image, of course, will be reversed (upside down). With the right hand reach to the front of the camera and extend the bellows by moving the front section containing the lens. Slide it backward and forward until the image appears perfectly distinct and sharp on the ground-glass.

Correcting the Focusing Scale

After securing proper focus, measure the distance from camera to object, and if this distance agrees with the figure indicated on the focusing scale, then the scale is correct. If they do not correspond, the scale can be corrected by focusing on some object 100 feet away. When a correct focus is secured at this given distance, and the actual distance does not register correctly with the pointer on the focusing scale, then remove the plate containing the scale and replace it so that the figure 100 is opposite the pointer. The rest of the scale will then be found to be all right. However, when possible, in order to insure perfect focus, it is advisable to focus on the groundglass, paying no attention’ to the scale. When using the camera without a tripod for snap-shot work, it is convenient, of course, to have the scale, and, therefore, it should be correct. As all reputable manufacturers test their instruments very carefully for this particular feature, it will be found that they are, in almost every instance, correct.

Finders

Most hand cameras and kodaks are fitted with a little box covered with a metal hood, a lens in the front of it and a small piece of glass on the top. This is called a finder, and is, in effect, a miniature camera. Everything visible on this finder will be visible on the ground-glass, and everything visible on the ground-glass should be visible on the plate when developed. Finders are fitted with fixed focus lenses, and, therefore, the object at any distance will naturally appear sharp on the finder.

If it is desired to secure the focus by the scale on the side of the camera, as, for instance, in kodaks, judge carefully the distance to the object to be photographed. With a little practice this can be accomplished successfully. A good plan is to measure by strides, and by pacing off the distance it will then be possible to judge more accurately the right number of feet. The better way, as said before, is to focus on the ground-glass. The finder should only be used when the instrument is employed as a hand camera; i.e., without the tripod. Thus, the object to be photographed will be located in the finder instead of on the ground-glass. Remember, the finder is only used for locating the object, but not for focusing. The focusing must be done either on the ground-glass or with the scale.

Fixed Focus Box Cameras Require No Focusing

The fixed focus or box cameras contain no scale. As they are all a fixed general focus, such cameras need no focusing, and whatever is visible in the finder will appear in focus on the plate or film. But with all other folding cameras containing focusing scale or ground-glass, the focus must be obtained by the above method and not in the finder. Use the finder only for locating the view on the plate. Always remember, first, to locate the view in the finder, for whatever is visible in the finder will be registered on the plate. If the camera is pointed at a building and it looks crowded in the finder, then step back farther from the building until good proportions of margin all around are secured. Judge the distance from the object or building and draw out the bellows until the pointer registers opposite the number of feet which is the distance between the camera and the object. The exposure can now be made.

Rising, Falling and Sliding Front

Practically all folding cameras have a rising and falling front, i.e., it is possible to raise and lower the front-board to which the lens is attached. To a certain extent, this feature takes the place of a swing-back or swing-bed. When photographing a building that is not too high and your camera has only the rising and falling front but no swing-back or swing-bed attachment, the camera should remain perfectly level so that the ground-glass will be parallel to the building. To provide more space or sky above the building, or should the building be so high as to make it difficult to get the top of the building on the plate, raise the front-board, to which the lens is attached. Where the camera is fitted with a swing-bed, as well as with a rising front, both should be employed when photographing extremely high buildings.

Many folding cameras have, in addition to the rising and falling front, a sliding front, which is of great advantage when working in confined places. It is possible, by moving the sliding front one way or the other, to secure more or less of either side of a view without altering the position or moving the camera whatsoever; but it is very seldom necessary, in fact it is not so convenient in most cases, to use the sliding front as it is to slightly turn the camera on the tripod head.

Swing-back and Swing-bed

While all folding cameras are not supplied with swing-backs nor even swing-beds, many have one or the other of these attachments. The following is a brief description of their use:

The swing-back is at the rear of the camera and is so adjusted that it permits the ground-glass to swing perpendicular regardless of the angle at which the camera is tilted.

The swing-bed is simply the front or bed of the folding camera containing the track on which the sliding front moves, and the supporting arms or braces which hold this bed in position are so arranged as to make it possible to adjust the bed to any desired angle, thereby enabling you to admit as much sky or exclude as much foreground as desired. In this way the body of the camera can remain in any position at all times, and the ground-glass will always be perpendicular.

The swing-back or the swing-bed should be used when photographing extremely high buildings in order to obtain rectilinear lines. When photographing a high building it is necessary to point the lens upward, and if your instrument is fitted with the swing-back this back must be so adjusted as to keep it in a perpendicular position at all times. On the other hand, if your camera has a swing-bed, the camera itself should at all times remain in the same position (i. e., the ground-glass must always be perpendicular), but the swing-bed can be raised and fastened in position, which will give you exactly the same effect as to operate the swing-back (when the whole camera is pointed upward). Whenever the camera is tipped without any change being made in the position of the ground-glass the lower portion of the building will be nearer to the camera than the top, and the nearer an object is to the camera the larger it will appear on the ground-glass and it is, therefore, quite obvious that the lower portion of the building will appear larger and broader than the top. When pointing the camera upward it is necessary to pull the swing-back out at the bottom, which tips the top of the swing-back toward the building, making the ground-glass parallel to the building, or the object being photographed. Of course, when using an instrument equipped with the swing-bed the ground-glass always remains parallel with the building and this difficulty will not be encountered.

Horizontal Swing

Most view cameras, and many of the better class hand cameras, are provided, in addition to the perpendicular swing, with a horizontal one, the object of this being to bring into focus those objects which are nearer to the camera at one side than those on the other, as, for instance, a street scene showing the line of buildings on one side of the street which is being photographed at an angle. The buildings nearer to the camera may be brought into sharp focus, in which case those in. the distance will be indistinct, and by the horizontal swing these latter can be brought into approximate focus with those nearer to the camera.

Double Swing is the combination of the horizontal and vertical swings, by which any of the corrections of the image previously mentioned can be made.

Rack and Pinion

Most of the higher class folding cameras are supplied with rack and pinion movement, especially those which have a double extension or those with an extremely long bellows. On the side of the bed of the camera is a milled head. By pulling this out and turning it the bellows will be extended. This rack and pinion is, of course, used for accurate focusing.

Tripod

The tripod is an accessory employed as a stand or support on which to place the camera while focusing, or making time exposures. The objection to its use, in instantaneous work, is the time it takes to place the camera upon this stand.

The tripod, as its name implies, consists of three legs, each of which can be lengthened or shortened as desired; thus, it is possible to get it into a very compact form. These legs are attached to a head, upon which the camera is fastened by means of a thumb screw. As previously stated, in instantaneous work you can make the exposure by holding the camera in your hand; but for making time exposures you should use the tripod. One of sufficient rigidity should be employed so that when making the exposure the camera will remain absolutely steady, for the least movement during exposure will cause a blurred image.

When the camera is attached to the tripod, one leg should be under the bed of the camera, pointing toward the object to be photographed. This will leave one leg at each side of the rear of the camera, thus permitting easy focusing, and observation on the ground-glass of exactly what is to be produced by the plate. By this arrangement all of the legs of the tripod will be out of the way.

Another advantage in this arrangement is: Should it be desired, while focusing, to raise or lower the front of the camera, this can be easily accomplished by simply bringing the front leg closer or extending it farther from the camera.