SU1646A1 - SLR camera with monocle - Google Patents

Description

The author proceeds from the following considerations: A simple flat convex glass (monocle) with a large aperture gives a portrait image with soft contours and shadows that do not require retouching. The connection of a monocle with a mirror camera gives the best results, but at the same time the following significant disadvantages are obtained: the high cost of the instrument, the presence of a curtain shutter, etc .; All the advantages of the SLR camera were destroyed due to the fact that one had to make a correction in focusing on the focus on the difference between the optical and chemical foci of the monocle (this correction when pointing to infinity equals i / so of the main focal length of the monocle, and for close objects it reaches ; the need to make this amendment made it impossible to look at the subject to be removed until the very last moment before shooting); the rustling of the curtain shutter unnerved the subject and affected the quality of work — the ease of posture was lost. with a monocle, it aims to get a cheap photographic device, which could be used to produce, mainly, artistic portrait photography. and in fig. 2 is a beam refraction diagram. Fig. 1 with a front sliding part equipped with a monocle and having a folding mirror c inside and a movable opaque glass d, over which there is a conventional folding light-proof umbrella, through which the image of the subject taken through the cassette is viewed. The mirror with can be raised and lowered. Frosted glass can be somewhat raised and located not in the same way as in an ordinary mirror camera, but in such a way that when a monocle is aimed at infinity its light focus gives a sharp image on the ground glass located in the lowest glass offered. Reflex camera In FIG. 1 shows a camera, a reflex camera representing of with a conventional lever type

 2, while raising the mirror C has a chemical focus. Daunbkl falls just on the photographic plate. When hovering on an object that is remote to infinity (practically more than 10 meters), a chemical focus is obtained from the monocle on the frosted glass. If you shoot a close object (portrait), then to fulfill the same condition as before, depending on pushing the monocle b forward, the opaque glass d will be slightly raised, depending on the monocle b. In the proposed camera, this is done automatically with the help of a special transfer from the crestal. This transfer can be carried out in a wide variety of ways. For the determination of color B - 25; 22.3; 21.4; 21.1; 2 The correction X to the corrected focus is determined by the formula: 50 / cost, to which the matte glass should be moved, depending on the distance of the iredmet, and an example of a monocle with a main focus distance of 20 cm is given. () .; The distance B from the center of the lens to the frosted glass is determined by the formula 5 - (Fig. 2). In this formula, the g-distance of the subject to the center of the monocle and / is the focal distance of the monocl. According to this formula, B is obtained for successive distances of 100, 200, 300, 400, 500, 600, 700, 800, and 1000 cm. At cm, it is obtained, respectively, in cm:, 8; 20.7; 20.6; 20.5; 20.4; Calculating this amendment using this formula for different distances and substituting instead of B for the above values found, get x in mm. when g in cm:

For a distance of 3 to 8 meters, i.e. Of the distance from which portraits are taken, on average, the X correction is 4.39 mm. This average amendment differs from the extreme corrections by 0.19 mm, i.e. on almost insignificant, insignificant value. Therefore, the movement of ground glass may be absent; Frosted glass should be moved further than normal for this case by 4.39 mm.

In a camera of the usual type (not a mirror), it is sufficient to move the frosted glass away from the monocle by the amendment X and fix it here. If you take a monocle with / 20, then the frosted glass in an ordinary camera will have to be fed back from the monocle by 4.39 mm. and fix here.

The frosted glass setting may vary depending on the length of the focal length of the monocle and the purpose of the shooting.

In the proposed camera, there is no other instant shutter other than a movable mirror.

The practice of the author has shown that in pavilion or room photography, using an ordinary photographic SLR camera for shooting, for example, portraits, it is not necessary to use the curtain shutter and the exposure can be done only by raising and lowering the mirror.

SUBJECT OF PATENT.

A mirror camera with a monocle, characterized by the use of a vertically movable at the top of the camera, frosted glass d and a folding mirror c, which serves both to reflect the image on the frosted glass and as a shutter during shooting. Kpatent

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.. V.V. KOVRIGINA.