JPH04233533A - Camera for infrared film - Google Patents

Abstract

PURPOSE:To automatically correct a focal point when the focal point which is adjusted by eyes must be corrected to the focal point of infrared rays in the case of photographing by the use of an infrared film, because the chromatic aberration of the photographing lens of a photographic camera such as a lens shutter camera or a single lens reflex camera is corrected in a visible light region. CONSTITUTION:A range-finding part DM for measuring the distance of an object, an infrared film detecting switch IS for discriminating whether the film used is the infrared film or not, a ROM LR which outputs information concerning the infrared correction of the photographing lens are provided, and a control microcomputer muC discriminates based on the discriminated result of the switch IS that the film used is the infrared film. A lens driving part LD corrects the focal point and performs focusing based on correction information from the ROM LR.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to photographic cameras such as lens shutter cameras and single-lens reflex cameras, and more particularly to cameras that can use infrared film.

0002

2. Description of the Related Art When photographing with an infrared film using a photographic camera, it is necessary to adjust the focus and then refocus the infrared light. This is because the chromatic aberration correction of the photographic lens is performed within visible light, so the focal position of infrared light deviates from the focal position of visible light. Therefore, a red or R mark is provided as an infrared mark on the lens barrel for correcting the focal position of the infrared light with respect to the distance scale. When shooting with infrared film on a manual focus camera, look through the camera's viewfinder, focus, look at the distance scale displayed on the shooting lens, read the distance indicated by the index, and then calculate the distance value at that time. The process involves taking pictures in line with the infrared correction mark shown on the photographic lens.

0003

[Problems to be Solved by the Invention] Therefore, compared to the case of using ordinary film, there is a problem in operability since two operations are added: reading the distance scale and correcting the distance value. Furthermore, when performing correction operations, there is a problem in that the photographer takes his eyes off the viewfinder, causing him to miss a photo opportunity. Also, when taking pictures using an infrared film with an autofocus camera, after adjusting the focus using the camera's autofocus, switch the camera's focus mode to manual and adjust the shooting lens to You must read the distance indicated by the index by looking at the displayed distance scale, and then take the picture by aligning the distance value with the infrared correction mark shown on the photographic lens. There was a problem in that the photo opportunity was missed because the camera was moved away from the camera.

0004

[Means for Solving the Problems] The present invention includes a distance detecting means for detecting the extended position of a photographic lens, a discriminating means for discriminating whether or not the film used is an infrared film.
By providing a correction information output means for outputting information regarding infrared correction of the photographic lens, and a correction means for correcting based on the correction information from the correction information output means when the film used is an infrared film, it is determined by the determination means that the infrared correction is automatically corrected. We have realized an infrared film camera that performs external correction.

[0005]

[Function] Therefore, according to the present invention, even when using an infrared film, it is possible to take a photograph without manually correcting the focus after adjusting the focus in the same way as when using a normal film. can.

[0006]

Embodiments Hereinafter, embodiments of the present invention applied to a single-lens reflex camera will be described with reference to the drawings. FIG. 1 is an electrical circuit diagram of the camera. In the figure, (μC) is a control microcomputer that controls sequences related to autofocus control of the camera. (DM) is a distance measuring section, which transmits the object distance measured through the photographic lens to the control microcomputer (μC). (LR) is the ROM (Read) built into the photographic lens.
Only Memory) is used to transmit various information about the lens to the control microcomputer (μC). (LD) is a lens drive unit that drives the photographic lens under the control of a control microcomputer (μC). (EC) is an exposure control section that controls the aperture and shutter speed to obtain appropriate exposure. And (S
) is an infrared film detection switch, which closes when using an infrared film. The infrared film detection switch (S) is a manually operated switch that is closed when an infrared film is used.

The switch (S1) is closed by the first step of pressing down the release button (not shown), and when this switch (S1) is closed, a "Low" level signal is sent to the input terminal of the control microcomputer (μC). A signal is applied, and in response, a ranging operation is started. The switch (S2) is closed by the second step of pressing down on the release button (not shown), and a "Low" level signal is input to the input terminal of the control microcomputer (μC), the exposure control section operates, and shooting begins. is completed.

FIG. 2 is a flowchart illustrating the operation of the present invention.

By the first stage of the release operation, a distance measuring operation is started in step #1. In step #2, lens information is input from the ROM of the interchangeable lens. In step #3, the focusing lens is controlled based on the distance measurement data. Next step #4
It is determined whether the film used is an infrared film or not, and if it is not an infrared film, this routine is exited.
The second stage of the release completes the release operation and ends the photographing. When the film used is determined to be an infrared film in step #4, the focus is corrected in step #5 based on the lens-specific infrared correction amount information input in step #2. Then, the second release step completes the release operation and ends the photographing.

Although this embodiment has been described using a manual switch, it is also possible to display an indication of infrared film on the film cartridge, such as a DX code, and read it when the film is loaded into the camera.

[0011]

[Effects of the Invention] By using the present invention, even when taking pictures using an infrared film, it is possible to take pictures without taking one's eye off the finder in the same way as when using a regular film.

[Brief explanation of the drawing]

FIG. 1 is an electrical circuit diagram of a camera.

FIG. 2 is a flowchart explaining the operation of the present invention.

[Explanation of symbols]

μC control microcomputer DM Distance measurement section LR ROM LD lens drive unit EC exposure control section IS Infrared film detection switch S1 switch S2 switch

Claims (1)

[Claims] [Claim 1] Distance measuring means for measuring the distance to a subject;
a determining means for determining whether or not the film used is an infrared film; a correction information outputting means for outputting information regarding infrared correction of the photographing lens; and a correction information outputting means when the determining means determines that the film used is an infrared film. An infrared film camera comprising: a correction means for correcting based on correction information from the means.