JPH041536Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Technical field of invention) The present invention relates to a lens barrel capable of close-up photography.

(Background of the Idea) Conventionally, in this type of lens barrel, there is known a lens barrel that allows close-up photography with high imaging magnification by interposing a close-up ring between the lens barrel and the camera. With such a lens barrel, when the magnification for close-up photography is increased, the image quality tends to deteriorate. Especially in lens barrels equipped with a short-distance correction mechanism,
If you set the same magnification (for example, 1/2x) and take pictures with the close-up ring and with the lens alone without using it, you will find that the image quality is inferior in the former case. Ta. The reason for this is that when setting the magnification to 1/2 with the lens alone, the lens is extended by turning the distance setting ring in the direction of close distance, so the close distance aberration correction mechanism is activated.
When setting the magnification to 1/2 using the close-up ring, the distance setting ring is rotated toward infinity to retract the lens, which means that the close-range aberration correction mechanism no longer works. This deterioration in image quality when using the close-up ring can be improved by stopping down the aperture, but the photographer does not know at what magnification and by how much the aperture should be stopped.

(Purpose of the invention) An object of the invention is to obtain a lens barrel that allows appropriate aperture to be performed in order to prevent image quality deterioration during close-up photography.

(Summary of the invention) To achieve this purpose, the lens barrel of the invention has a photographic magnification scale that changes the indicated value in conjunction with distance adjustment operation in order to make the photographic magnification visible during close-up photography. , an aperture value scale arranged in parallel with the photographing magnification scale, and the aperture value scale allows the aperture value to be changed in accordance with the photographing magnification in order to prevent image quality deterioration during close-up photography to be visually recognized. This is a characteristic feature.

(Example) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows the appearance of an embodiment in which the present invention is applied to an interchangeable lens barrel. When the lens barrel is attached to the camera, the index ring 1 and the depth scale ring 2 become integrated with the camera. A distance adjustment ring 3 is provided on the outer periphery of the depth scale ring 2 so as to be rotatable about the optical axis O of the lens barrel. An index 1a is provided on the outer peripheral surface of the index ring 1.
is engraved. On the outer peripheral surface of the depth scale ring 2, there are depth scale lines 2a to 2 extending in the optical axis direction of the lens barrel.
e is printed. The outer peripheral surface of the distance adjustment ring 3 has a distance scale 3a in meters, a distance scale 3b in feet, a magnification scale 4 used when taking close-up pictures with the lens barrel alone, and a scale 4 used when taking close-up pictures using the close-up ring. A photographic magnification scale 5 to be used and an aperture value scale 6 to be set in order to improve image quality when taking close-up photographs using the close-up ring are printed respectively. The scales 3a, 3b, 4, 5, and 6 are arranged in the circumferential direction of the distance adjustment ring 3, and are arranged in parallel with each other at a distance in the optical axis direction of the distance adjustment ring 3.

FIG. 2 shows a developed view of the lens barrel of this embodiment. In the figure, it is assumed that a predetermined close-up ring is attached between the lens barrel and the camera to take close-up pictures. In order to know the photographic magnification obtained in this case, it is sufficient to read the numerical value on the photographic magnification scale 5 facing the center depth scale line 2c facing the index 1a. In the case of the same figure, it can be read as "1.6". This value means a photographic magnification of 1/1.6x, which is the photographic magnification when using the close-up ring. In order to know the necessary aperture value to prevent the deterioration of image quality that occurs in this case, use the scale line 2.
All you have to do is read the numerical value on the aperture value scale 6 facing c. In the case of the same figure, it can be read as "5.6~32". This means that deterioration in image quality can be prevented by setting the aperture value between 5.6 and 32.

The relationship between the photographic magnification and the aperture value necessary to prevent image quality deterioration when taking close-up photographs with this lens barrel attached with a close-up ring can be seen by looking at the photographic magnification scale 5 and the aperture value scale 6. It looks like this: In other words, when the imaging magnification is 1/2 or more, 1/
If the magnification is less than 1.6, set the aperture value between 11 and 32. If the magnification is 1/1.6 or more and less than 1/1.3, set the aperture value between 5.6 and 32. If the magnification is 1/1.3 or more, set the aperture value to 1/1. If the magnification is less than 1, set the aperture value between 4 and 32. If the magnification is 1/1 or more, set the aperture value to 2.8.
It is recommended to set the value between 32 and 32.
The reason why the aperture value can be reduced as the photographic magnification increases is because the lens barrel of this embodiment has a built-in close-range correction mechanism, and when the photographic magnification is large (that is, when the distance adjustment ring 3 is set close to the close distance) This is because this correction mechanism works during this period), suppressing deterioration in image quality.

FIG. 3 shows the external appearance of another embodiment in which the present invention is applied to an interchangeable lens barrel, and members equivalent to those in the previous embodiment are given the same reference numerals and explanations will be omitted. In this embodiment, there is a magnification scale 4' used when taking close-up pictures with the lens barrel alone, a magnification scale 5' used when taking close-up pictures using the close-up ring, and an image quality scale used when taking close-up pictures using the close-up ring. A scale 6' indicating the aperture value to be set for improvement is printed not on the outer circumferential surface of the distance adjustment ring 3 but on the depth scale ring 2 along with the depth scales 2a to 2e. Each of the scales 4' to 6' is arranged in the optical axis direction of the depth scale ring 2,
They are arranged in parallel with each other at a distance in the circumferential direction of the vibration scale ring 2. The distance adjustment ring 3 of this embodiment is adapted to be displaced in the optical axis direction with respect to the depth scale ring 2 by an amount proportional to the amount of rotation.

In the figure, it is assumed that a predetermined close-up ring is attached between the lens barrel and the camera to take close-up pictures. In order to know the photographic magnification obtained in this case, it is sufficient to read the numerical value on the photographic magnification scale 5', which is closely opposed to the end surface of the distance adjustment ring 3. In the case of the same figure, it can be read as "1". This value means a photographing magnification of 1/1, which is the photographing magnification when using the close-up ring. In order to know the numerical value of the aperture necessary to prevent the deterioration of image quality that occurs in this case, it is sufficient to read the numerical value on the aperture value scale 6', which is closely opposed to the end surface of the distance adjustment ring 3.
In the case of the same figure, it can be read as "2.8~32". this is,
This means that if you set the aperture value to a value between 2.8 and 32, you can prevent deterioration in image quality.

(Effects of the invention) As described above, according to the invention, the recommended aperture value for the shooting magnification during close-up photography is displayed on the adjustment ring as the recommended aperture value range. The photographer can freely select the desired aperture value from among these, and as a result, it is possible to prevent deterioration in image quality during close-up photography and to obtain photographs that meet the photographer's expectations.

In addition, the external appearance of the adjustment ring includes a mixture of displays such as a distance scale display section, a photographing magnification scale display section, and an aperture value scale display section. The display section, magnification scale display section, and aperture value scale display section are displayed, so the distance scale display section is displayed closest to the index during normal shooting, which is frequently used, and when shooting close-up shots, which are less frequently used. The magnification scale display section and the aperture value scale display section are displayed in this order, making it easy for the photographer to correspond with the index and make the display easy to read.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the appearance of an embodiment of the present invention;
FIG. 2 is a developed view of the same embodiment, and FIG. 3 is a front view showing the external appearance of another embodiment of the present invention. Explanation of the symbols of the main parts, 5, 5'... Shooting magnification scale, 6, 6'... Aperture value scale.

Claims (1)

[Claims for Utility Model Registration] An indicator visibly displayed on a fixed lens barrel that is fixed to the camera body when attached to the camera body, and an adjustment ring rotatably attached to the fixed lens barrel. In this case, on the end surface of the adjustment ring on the index side,
a distance scale display section that displays a plurality of object distances during normal shooting along the circumferential direction, and in which the value of the object distance indicated by the indicator changes in conjunction with the operation of the adjustment ring; arranged in parallel with the distance scale display section on the end surface, displaying a plurality of photographing magnifications for close-up photography;
a photographic magnification scale display section that changes the value of the photographic magnification indicated by the index in conjunction with the operation of the adjustment ring; and a photographic magnification scale display section that is arranged in parallel with the photographic magnification scale display section on an end surface of the adjustment ring, and is arranged in parallel with the photographic magnification scale display section on the end surface of the adjustment ring, and and an aperture value scale display section on which a recommended aperture value is displayed, and the distance scale display section, the photographing magnification scale display section, and the aperture value scale display section are displayed sequentially from the index side. The aperture value scale display section is a cylinder, and the aperture value scale display section has a first aperture value scale display representing a first recommended aperture value range corresponding to a first scale area of the photographic magnification scale display section, and a first aperture value scale display that is different from the first scale area. a second aperture value scale display corresponding to a second scale area of the photographic magnification scale and representing a second recommended aperture value range that is partially different from the first recommended aperture value range; A lens barrel capable of close-up photography, characterized in that the recommended aperture value that should correspond to the photographing magnification is made visible to prevent image quality deterioration during close-up photography.