| 摘要 |
PURPOSE:To obtain an excellent resolving power in case of photographing by a long focal distance even if some eccentricity exists in a main lens system, an rocking axis of a rear converter frame, etc., by using a holding structure of a conversion lens in which a lens frame of the conversion lens is fitted and attached so as to be turnable to a holding frame, and a relative position to the holding frame is held at an optional turning position. CONSTITUTION:When fitting and attaching a lens frame 2, it is inserted into a round hole 1b from the direction as indicated with an arrow, elastic arms 1c, 1c' of a holding frame 1 are opened to the right and left so that a distance between its tip parts becomes larger than a diameter of the outside peripheral part of the front end of the lens frame 2, also the lens frame 2 is inserted until a step difference surface 2a' of a fitting outside diameter part 2b and a large diameter part 2a hits against the surface of the holding frame 1, and the opening of the elastic arms 1c, 1c' is released after a stage in which the front end outside peripheral part of the lens frame 2 has reached a position of the elastic arms 1c, 1c'. When the lens frame has been fitted and attached, the lens frame 2 is turned in the round hole 1b of the holding frame by utilizing a notch 2d provided on the lens frame 2, and a turning position phase for obtaining the most excellent resolving power is derived together with a main lens system. In this way, when the alignment has been ended, it is desirable that the holding frame 1 and the lens frame 2 are fixed by an adhesive agent. |
