A few years ago the field camera and the hand camera were two distinct types, with clear demarcations. But the Sanderson on the one hand, and the better class of Kodaks on the other, have led the way towards a compromise between the two. We can buy compactly built, portable cameras with every movement, swing front, swing back, folding baseboard, triple extension, just as well equipped as a field-camera for the same size of plate. We illustrate a few of these; the price varies considerably, and each has advantages that make it worth the price. The beginner need not insist on all these features, if he does not contemplate an equipment necessary to face very difficult problems of architecture in narrow courtyards, or very long-focus lenses for taking animals in their native haunts, etc. Double extension is very desirable, and a rising front indispensable. Chiefest of all is the focussing screen, in order that practice in composition with the camera on the stand may be always available. And this is not the only use of the focussing screen. Without occasionally referring to it, no one can have real knowledge of the limitations of his lens; there is no other means of acquiring the power of seeing a picture as the camera sees it, which is the foundation of every real photograph.
Fig. 54. The Sinclair "Una" At Normal Extension.
But it is not reasonable to insist on every photograph being focussed on the stand before it is taken. We ourselves always carry a stand in the satchel, but often do not unpack it for whole days. When once we know our lens, and are in full sympathy with it, focussing on the stand is only required for elaborate landscapecomposi-tions, groups, or portraiture of a high order. For eight months of the year full exposures can be given with the camera held in the hand unless the weather is very dull, and for ordinary composition the view-finder will provide the experienced eye with all essential data. The ideal position for the view-finder is attached to the rising front just above the lens; unfortunately it is very liable to be knocked askew during those rough moments that attend the career of the most jealously guarded hand camera. The next best position is inset into the body close beside the level, so that the operator can keep the two simultaneously in view. Somehow we do not get on, as regards levelling, with "direct" view-finders, although we acknowledge their prime advantage of enabling the camera to be held at the height of the eye. View-finders on the body of the camera necessitate mental calculation when the subject is within 6 ft, and also when the rising front is in use - and the latter, so we find, is wanted for nearly every picture, or there will be a long stretch of ugly, useless foreground. The finder should be bright, and should give exactly the same amount of view as is seen on the plate.
Fig. 55. The Adams "Vaido."
Fig. 56. The Watson "Alpha".
On the baseboard of every focussing hand camera is a scale of distances from 5 to 30 or 50 ft. indicating the point at sharpest focus. Some people seem quite unable to estimate distances quickly and accurately, and the only way seems to be practice with chalk marks on a pavement. Even a foot or two may prove a serious error when working at f/6.5 within 10 ft. of the lens, and, especially when enlarged, a picture is apt to betray its fault when the principal object is not in fuller focus than other subsidiary objects.
This is very important to bear in mind when focussing by scale, in order that objects in the foreground may not turn out to be glaringly out of focus. Short-focus lenses are not so likely to show this fault as those of longer focus. When in doubt, either avoid the foreground altogether or focus for it. Directions how to calculate depth of field are given in Chapter V (The Optics Of Photography (Continued)), but a few rough calculations for the guidance of beginners are subjoined.
Fig. 57. The "Sybil" Camera.
Distances of focal centre .
10 to infinity.
Distances of focal centre
13 to inf.
12 to inf.
8 to inf.
9 to inf.
The above tables show amongst other things the great advantages of a short-focus lens when working with the hand camera by scale.
On the focussing scale at 30 ft. or upwards we shall see a distance marked "Infinity," which indicates that when an object is focussed at, this distance with the largest stop in the lens, everything beyond it will be in focus. The infinity mark is a distance dependent on the focal length of the lens, decreasing in proportion with the stop used. Thus at f/6.5 the infinity mark is reached at about 32 ft. with a 5 in. lens, but if we reduce the stop to f/8 it is reached to all intents and purposes at 25 ft., and with f/11 at 20 ft. All objects beyond half the distance from the camera to the infinity mark will also be in focus.
Here we have the secret of the fixed-focus camera. If we set a camera with a 5 in. lens at 32 ft, all snapshots taken at objects beyond 16 ft. will be in fair focus at f/65. But if we are willing to work at f\11 there is the enormous advantage of being able to take anything at a distance beyond 10 ft, and get pictures sufficiently sharp for enlargement. Many cameras are now constructed to spring out automatically to infinity. But we gain very much in range for nearer objects, and incidentally in pictorial effect, if we calculate the mark of infinity for the particular stop we intend to use in the lens. And for all practical purposes, that is to say, when there is no very distant landscape to consider, the infinity mark for a 5 in. lens is reached when the depth of field approaches 100 ft. Even with a 6 in. lens the infinity mark f/11 may be taken at 30 ft. against a figure nearer 40 ft at f/8. Of course, if we consider the higher capacities of lenses these figures are inaccurate and worthless. But then, no one expects of a fixed-focus camera good pictures of Alpine scenery, any more than we should employ them for portraits within a few feet of the lens.
Closed, as carried ready for ordinary work.
Open, to show fittings and movements.
Fig. 58. The Newman And Guardia Universal Camera.
A snapshot we define as a plate exposed on the spur of the moment; one which we have no time to focus or compose either by means of the focussing screen or a scale of distance. We can go snap-hunting with the ordinary hand camera fixed at infinity, but it is hardly advisable to carry about a high-class instrument dangling down, with the bellows and delicate gear unprotected. Still worse to expect that we shall have space and opportunity to secure the quarry; many a time when wandering in the woods a squirrel has come within range; at the mere click of setting the shutter he has been off out of sight. With very little trouble and ingenuity a box of light wood can be adapted to serve as the body of a fixed-focus lens; we can screw the lens and iris shutter into the front, and provide clips for the movable back of our high-class camera. The length must be the fixed focus for f/11, which in that case must be the largest stop employed; and as already stated will provide us with an efficient instrument, ready set for all objects over 10 ft. distance from the lens.