Excerpts from the book "Cameras and Optics"
Camera "Leningrad" (fig. 62) — a new small-format camera with automatic shutter cocking, film winding, and a universal fast viewfinder-rangefinder.
Thanks to the presence of special frames visible in the field of view, it is possible to use interchangeable lenses with focal lengths of 35—135 mm. The viewfinder-rangefinder eyepiece has diopter adjustment for the eye.
The main lens of the camera is "Jupiter-8" with a focal length of 50 mm and an aperture of 1:2.
The threaded lens ring has the same dimensions as the lens ring in the "Zorki" and "FED" cameras.
The working distance of the camera allows the use of interchangeable lenses with a working distance of 28.8±0.03 mm (interchangeable lenses for "Zorki" cameras).
The shutter design is similar to the shutter design of the "Zorki-4" camera. The shutter has the same range of speeds and a self-timer mechanism.
The "Leningrad" camera is equipped with a synchrocontact with two pin connectors and a sync device.
The back cover of the camera is removable. The cassettes have an opening slot (from the "Kiev" camera).
Hyperfocal Distance
1. When focusing on the infinity scale of the camera, the sharp image space starts from a distance called the hyperfocal distance and can be calculated by the following formula:
D = K2 / k × d
where D — hyperfocal distance,
f — focal length of the lens,
k — denominator of the relative aperture (numbers on the lens aperture scale),
d — accepted circle of confusion diameter.
For example, for the "Ortagoz" lens f = 135 mm in the "Fotokor No. 1" camera with a size of 9 × 12 cm, e.e. = 0.1, when focusing on infinity, the sharp image space starts from a distance:
D = 1352 / 9 × 0.1 = 20250 cm = 20 m 25 cm.
This is the hyperfocal distance for this lens at this aperture.
It is recommended for every photo enthusiast to calculate the hyperfocal distances for all apertures of their camera and include the table in a notebook or attach it to the camera.
For the "Moscow" camera with a 110 mm lens at aperture 6 (e.e. = 0.1), the value of which is 8 m 5 cm, the hyperfocal distance table will look like this:
| Aperture scale number (k) |
Hyperfocal distance (D) |
| 4.5 |
5.5 m |
| 5.6 |
6.8 m |
| 8 |
10.9 m |
| 11 |
15.0 m |
| 16 |
21.8 m |
| 22 |
30.0 m |
| 32 |
42.6 m |
Focusing on ∞ is not always advisable. It is more practical to focus on the hyperfocal distance, as in this case the front boundary of the sharp image space will be at half the hyperfocal distance from the camera, and the rear boundary at ∞.
For example, if the "Moscow" camera with a 110 mm lens at aperture 6 is focused on a hyperfocal distance of 6.8 m, then the front boundary of the sharp image space will be 3.4 m from the camera, and the rear boundary at ∞.
Wanting to get a sharp image space within certain boundaries, you first need to decide at what distance it is advisable to focus.
Editor: A. N. Telesheva
Art Editor: Z. V. Vorontsova
Artist Designer: G. B. Lebedeva
Technical Editor: Z. N. Malek
Proofreader: E. M. Stankevich
Submitted for typesetting on 20/I 1958. Signed for printing on 14/V 1958. Form. paper size 84X108 1/32. Printed sheets 5.19 (cond. sheets 8.51). Publishing sheets 9.01. Circulation 200,000 copies. Ш03457. "Iskusstvo", Moscow I-51, Tsvetnoy Boulevard, 25. Publishing № 16213. Order 1360.
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