THE PINHOLE FOR WIDE ANGLES.

BR

By J. A. ANDERSON.

ECENTLY a picture of a church building was wanted, for which the only practicable point of view was directly in front, on a narrow street, which abutted on the principal street upon which the church was situated.

With a lens of sufficient focal length for a proper rendering of the perspective, the necessary distance of the camera from the church brought into undue prominence the sides of the narrow street, with some signs and other objectionable features, besides rendering the church buildings subordinate in apparent size, to the nearer buildings along the street.

The only resource was a nearer position and a "wide angle" view. There being no lens available for this, the pinhole was used. The picture was taken from a point at a distance from the church about equal to its height and where most of the objectionable features were excluded. To get the building of suitable size, and properly placed on the plate, at such distance, required considerable elevation of the front board, in addition to tipping the camera, with corresponding use of the swing back, as well as a very short distance from the pinhole to the plate.

The plate was 5 x 7, distant about 31⁄2 inches from the pinhole, which was No. 4 of the system recommended in The Photo-Miniature, No. 70, on "Advanced Pinhole Photography." and the exposure was calculated by the method therein prescribed. In a dull light, measured by the Wynne meter, the calculated exposure was 45 seconds. An addition of 15 seconds was made to this on account of the lesser degree of illumination of the sides of the street, as compared with that of the church building.

The definition of the principal object was, of course, somewhat softened but not so much as to differ noticeably from the usual result with the lens. There appeared to be, perhaps, a little greater comparative degree of confusion at the sides.

which was not objectionable and may have been partly due to the short extension.

The very short extension necessarily used was much less

than that recommended as best by authorities on the subject, and the results in definition and illumination at the sides of the plate, might have been better with a greater distance. The subject of the effect of different degrees of extension is discussed in the number of The Photo-Miniature above referred to and in No. 27 of the same publication.

It is well understood that the perspective is not satisfactory in wide angle pictures and it is best to avoid them when prac

ticable. The present case is no exception to the general rule, although the defect was reduced to a tolerable minimum by presenting the church building in comparatively large proportion and retaining as little as would seem desirable of the adjacent buildings.

In the matter of the rendering of the perspective the pinhole has no material advantage over the lens, for the same extension, but a point in its favor is that its extension may be varied, while that of the lens is controlled by its focal capacity.

It may be added, for pinhole experimenters, that the writer has found in German silver, about as thick as medium writing paper, a satisfactory metal, the punching being done in the manner described in The Photo-Miniature, No. 27, by a needle broken off at its largest part and ground square. In selecting needles it was found that those bearing the same number of the maker could not be relied upon for uniformity in size, so that the average of the measure of a number laid alongside of each other was not a correct indication of individual size. The test relied on was by a home-made gauge, which magnified the thickness 20 times and gave very satisfactory results in the final selection.

Upon the same day on which the church picture was taken, the pinhole was used for a picture, also a "wide angle," of an inscription on the side of a monument which stood so near the church as to allow but little more room than for the camera and a very short extension, with no space for the head in focusing. The size and position of the image had to be determined by calculation and measurement. The result showed the correctness of the manipulations, but the experiment was not an entire success, because of the inadequate illumination of the lettering. It is mentioned as a suggestion for an expedient in like circumstances.

It is not at all improbable that the pinhole is being largely used in the manner pointed out in the foregoing, but if so, the excuse for the present presentation must be that the writer does not happen to have met with any statement to that effect.

One of the illustrations herewith shows the church picture referred to, the other being a pinhole landscape with seven inches extension for a 5 x 7 plate.