JP2013109008A - Imaging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized and low-priced imaging system that includes an imaging unit having a built-in filtering function for adjusting light amount, which has conventionally required removal and insertion of ND filters.SOLUTION: The imaging system includes: a lens unit; an imaging unit connected to the lens unit, having an imaging element that receives subject light from the lens unit; two polarization filters on an optical path between the lens unit and the imaging element; and rotation driving means that can rotate at least one of the polarization filters along an axis parallel to an optical axis.

Description

  The present invention relates to an image pickup system including a lens device and an image pickup device, and more particularly to an image pickup system including an image pickup device including an optical filter therein.

  In a conventional imaging device such as a television broadcast camera, when adjusting the amount of light incident from a photographic lens, an ND filter is appropriately selected from a filter disk device containing a plurality of ND filters, and the selected filter is placed in the optical path In general, the amount of light is adjusted step by step by inserting.

In order to change the polarization direction, generally, a PL filter that is optionally attached to the front lens side of the photographing lens is turned by hand.
Patent Document 1 discloses a technique in which a filter disk composed of two gradation ND filters is arranged in the opposite direction and the light quantity is continuously adjusted by rotating the two filter disks. Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for configuring a retardation plate in a rotatable state in order to efficiently transmit the light amount of a projector light source and adjusting the polarization direction.

Japanese Patent Application Laid-Open No. 2007-243928 JP 2004-258063 A

However, in the prior art disclosed in Patent Document 1, the amount of light can be changed continuously, but in order to change the polarization direction by rotating the PL filter, it is necessary to newly provide a filter rotation mechanism.
The prior art in Patent Document 2 describes a mechanism for adjusting the amount of light by combining a polarizing plate and a rotatable phase difference plate in a projector optical system, but is a technology for efficiently transmitting the amount of light of a projector light source. Yes, not intended to correct shooting conditions.

Generally, to change the polarization direction, an optional externally attached PL filter is manually turned on the front lens side of the photographic lens. However, since a PL filter is provided on the front surface of the lens closest to the object, There is a problem that the diameter needs to be increased, the apparatus becomes larger, and the photographer is burdened economically.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to realize a dimming (ND) and polarization (PL) filter function required in accordance with photographing conditions in a device by using a small device and an inexpensive imaging system. Is to provide.

  In order to achieve the above object, an imaging system of the present invention includes a lens device, an imaging device to which the lens device is connected, and an imaging device that receives subject light from the lens device, the lens device, and the imaging device. Rotation drive capable of rotating two polarizing filters arranged on the optical path between the elements and at least one of the two polarizing filters about an axis parallel to the optical axis And means.

  According to the present invention, since the two polarizing filters are configured to be rotatable inside the imaging device, the light amount adjustment and the polarization direction can be performed without removing the filters from the optical axis, that is, without increasing the size of the imaging device. An imaging system capable of selecting an adjustment can be provided.

Optical layout of imaging system Conceptual diagram of transmitted light amount adjustment Graph showing variable state of transmitted light Polarization direction adjustment conceptual diagram Configuration diagram of the filter switching mechanism, (a) When the filter is inserted into the optical path, (b) When the filter is removed from the optical path Cross-sectional enlarged view of the main part of the filter switching mechanism Block diagram of the first embodiment Operation flow chart of embodiment 1 Details of the operation flow of the light intensity adjustment mode in FIG. Detailed operation flow of polarization direction adjustment mode in FIG. Filter switching mechanism of Example 2, (a) side view, (b) when a through filter is inserted in the optical path, (c) when a polarizing filter is inserted in the optical path Filter switching mechanism of Example 3 when a polarizing filter is inserted in the optical path, (a) side view, (b) front view, (c) bottom view Filter switching mechanism of Example 3 when a through filter is inserted into the optical path, (a) side view, (b) front view

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is an imaging system including an imaging apparatus in which two polarizing filters according to an embodiment of the present invention are configured to be rotatable on an optical axis.

  The configuration of the imaging system according to the first embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a diagram illustrating an optical basic arrangement of an imaging system including a television camera (imaging device) 1 and a photographing lens (lens device) 2. The imaging system of the present invention includes a television camera 1 and a photographing lens 2. The photographing lens 2 includes a diaphragm mechanism 3 that adjusts the amount of incident light, and a mount 4 that mechanically couples the television camera 1 and the photographing lens 2. The TV camera 1 has a dust-proof glass 5 and a film-like thin plate shape.

  A first polarizing filter 6a and a second polarizing filter 6b, an optical low-pass filter 7 for removing high-frequency components unnecessary for photographing, and a color separation prism 8 which is a color separation optical system for separating incident light into three colors In addition, imaging elements 9 a, 9 b, 9 c that receive subject light of each color light separated by the color separation prism 8 and an operation unit 10 are included. The operation unit 10 includes an aperture value adjustment knob 11, a filter selection switch 12, a mode selection switch 13, a light amount adjustment knob 14, a polarization direction adjustment knob 15, and the like.

  The polarizing filters 6a and 6b have a polarization direction perpendicular to the optical axis direction, and each filter is installed to be rotatable about the optical axis. FIG. 2 explains that the amount of transmitted light is adjusted by arranging two polarizing filters 6a and 6b arranged in the television camera 1 shown in FIG. FIG. Arrows 6a1 and 6b1 in FIG. 2 represent the polarization directions of the polarizing filters 6a and 6b, respectively.

  FIG. 3 is a graph showing the relationship between the rotation angle difference in the polarization direction of the two polarizing filters shown in FIG. 2 and the transmitted light amount ratio of the non-polarized light transmitted through the two polarizing filters. When the rotation angle difference (horizontal axis) is 0 degree, that is, when the polarization directions of the two polarizing filters 6a and 6b are the same direction (FIG. 4), it is the same as when one polarizing filter is used. The polarized light is transmitted as polarized light polarized in the polarization direction of the polarizing filter. In that case, the transmitted light amount is 50% of the incident light amount. When the rotation angle difference increases from 0 degrees, the transmitted light amount decreases according to the square of the cosine of the rotation angle difference, and when the rotation angle difference reaches 90 degrees, the transmitted light amount becomes zero. When the rotation angle difference between the two polarizing filters is 0 degree, the maximum transmitted light amount is 50%. Therefore, when the two polarizing filters 6a and 6b are inserted in the optical path, a variable range of 0 to 50% of the transmitted light amount with respect to the non-polarized light can be obtained.

  FIG. 5 shows a schematic diagram of a filter switching unit mechanism that is a polarization filter insertion / extraction means for inserting / extracting the two polarization filters 6a, 6b included in FIG. 1 into / from the effective optical path. The filter switching unit mechanism includes the polarizing filter frames 16a and 16b for holding the polarizing filters 6a and 6b, the polarizing filter holder 17 for rotatably holding the polarizing filter frames 16a and 16b, and the dimensions in the thrust direction of the polarizing filter frames 16a and 16b. Spacer 18 (18a, 18b, 18c, 18d) for regulating

  The polarizing filter holder 17 is driven by a motor A (19) so as to be inserted into and removed from the optical axis position (in the optical path), and the polarizing filter holder 17 is slidably held by slide pieces 20a, 20b, 20c, 20d, 20e, and 20f. Is done.

  FIG. 6 shows an enlarged cross-sectional view of a main part of the filter switching unit mechanism. The polarizing filter frames 16a and 16b holding the polarizing filters 6a and 6b are rotated on the optical axis by motors B (21a and 21b), which are rotation driving units, respectively, and change the rotation angle difference between the polarization directions of each other. be able to.

  The rotation angles of the polarizing filter frames 16a and 16b are detected by the encoders 22a and 22b. The optical axis position detection switch 23 detects that the polarizing filter holder 17 is at the optical axis position (the state shown in FIG. 5A), and the optical axis retract position detection switch 24 retracts the polarizing filter holder 17 from the effective light range. This is detected (state shown in FIG. 5B).

  FIG. 7 is a block diagram showing the electrical configuration of this embodiment. In the block diagram of FIG. 7, the light amount adjustment VR (14a) is a volume connected to the light amount adjustment knob 14, which is an angle difference indicating means for indicating a relative rotation angle difference between the polarization directions of the two polarizing filters. The polarization direction adjustment VR (15a) is a volume connected to the polarization direction adjustment knob 15 which is an angle indicating means for indicating the rotation angle (polarization direction) of the polarization filter. The CPU 25 has a function of calculating input information such as the filter selection switch 12 and current position information acquired from the encoders 22a and 22b and giving a drive or stop command to a motor drive circuit 27 described later. The AD converter 26 has a function of converting values of the light amount adjustment VR (14 a) connected to the light amount adjustment knob 14 and the polarization direction adjustment VR (15 a) connected to the polarization direction adjustment knob 15. The motor drive circuit 27 has a function of sending energization start and stop commands to the motor A (19) and the motor B (22a and 22b) from the command received from the CPU 25.

  Next, the operation flow of the present invention will be described using the flowchart of FIG.

After starting the operation flow in step S100, it is selected in step S101 whether to use a polarizing filter. When the use of the polarization filter is selected, the process proceeds from step 101 to step S102, and the state of the optical axis position detection switch 23 is checked to determine whether the polarization filter is at the optical axis position. When it is determined that the polarizing filter is at the optical axis position, the process proceeds to step S104, and the driving of the motor 19 that moves the polarizing filter frame is stopped. If it is determined that the polarizing filter is not at the optical axis position, the process proceeds to step S103, the motor 19 is driven to move the polarizing filter frame to the optical axis position, and the process returns to step S102. Steps S102 to S103 are repeated until it is determined that the polarizing filter is at the optical axis position.
In step S105 subsequent to step S104, an operation mode for selecting light amount adjustment or polarization direction adjustment is selected.

  When the light quantity adjustment mode that is the first mode is selected by the mode selection switch 13, the process proceeds to a subroutine of step S200, and when the polarization direction adjustment mode that is the second mode is selected, the subroutine of step S300. Proceed to

  If the use of the polarizing filter is not selected in step S101, the process proceeds to step S106, and the optical axis retracted position detection switch 24 checks whether the polarizing filter is retracted from the optical axis position to the retracted position. To do. If it is confirmed that the optical axis retracted position detection switch is ON and the polarizing filter is retracted from the optical axis position to the retracted position, the process proceeds to step S108, and the driving of the motor 19 that moves the polarizing filter frame is stopped. To do. If the optical axis retracted position detection switch 24 is OFF, the process proceeds to step S107, the motor 19 is driven to move the polarizing filter frame to the retracted position, and the process returns to step 106 to move the polarizing filter frame to the retracted position. Steps S106 to S107 are repeated until the above.

  Next, the operation flow in the light amount adjustment mode, which is the first mode, will be described with reference to the flowchart of FIG.

  After the light quantity adjustment mode operation flow is started in step S200, the light quantity adjustment VR value operated by the operator is read in step S201 and converted into an angle control indicating a relative angle difference between the polarizing filter 1 and the polarizing filter 2. In step S202, an angle obtained by adding or subtracting the angle control to the rotation angle of the polarization filter 1 detected by the rotation angle detection encoder 22a is set as an angle control value for the polarization filter 2. In step S203, the polarizing filter 2 is driven to be controlled by the position servo. Next, the process proceeds to step S204, and the subroutine flow is terminated.

  Next, the operation flow in the polarization direction adjustment mode, which is the second mode, will be described with reference to the flowchart of FIG.

  After starting the polarization direction adjustment mode operation flow in step S300, in step S301, the polarization direction adjustment VR value operated by the operator is converted into an angle control indicating the angle of the polarization directions of the polarization filter 1 and the polarization filter 2. In step S302, the control for the polarizing filter 1 is set to the angle control, and the control for the polarizing filter 2 is set to the angle control. In step S303, the polarizing filter 1 and the polarizing filter 2 are brought into a controlled state by the position servo. Next, the process proceeds to step S303, and the subroutine flow ends.

  Next, the mechanical operation contents in the above configuration will be described.

  When photographing a subject, various knobs and switches are operated from the operation unit 10 arranged in the television camera 1 according to conditions. For example, when shooting outdoors on a sunny day, it is common to reduce the amount of light incident from the taking lens, so use the aperture 3 of the taking lens 2 or filters 6a, 6b on the TV camera 1 side. It is necessary to judge whether to use. In a case where it is determined that the filters 6a and 6b on the television camera 1 side are used, first, in step S101, the filter selection switch 12 is set to the polarization filter ON. Next, proceeding to step S102, if the optical axis position detection switch 23 of the polarizing filter holder 17 is OFF, the process proceeds to step S103, where the motor A (19) is energized and the polarizing filter holder 17 is directed to the optical axis position in accordance with the rotation of the motor. And return to step S102. If it is confirmed in step S102 that the optical axis position detection switch 23 is ON, the process proceeds to step S104. If the motor A (19) is energized, the energization is stopped.

  In step S105, the mode selection switch 13 is operated to select the light amount adjustment mode. The process proceeds from step S200 to S201. When the light amount adjustment knob 14 is operated in step S201, the value of the rotation angle detection encoder 22a is compared with the value of the rotation angle detection encoder 22b to detect the current rotation angle difference between the polarization filter 1 and the polarization filter 2, and step In S202 and step S203, a drive command is output to the motor B (21b) so as to rotate the polarizing filter 2 by the difference from the command value. When the motor B (21b) is driven, the second polarizing filter frame rotates. As a result, a rotation angle difference from the first polarizing filter frame 6a is generated, and thus the transmitted light amount can be continuously changed within a range of 50% or less of the incident light amount. As shown in the graph of FIG. 3, if the polarization direction 6a1 of the first polarizing filter 6a and the polarization direction 6b1 of the second polarizing filter 6b are 0 °, the transmitted light amount is 50% and the angular difference is 90 °. If so, the amount of transmitted light is 0%, and during this time, the amount of transmitted light changes continuously according to the angle difference. When the desired condition is met, the knob operation is stopped, and the second polarizing filter frame 6b stops rotating according to the stop command.

  In addition, when there is a shooting scene in which the water surface appears to shine when shooting outdoors on a clear day, the mode selection switch 13 can be adjusted from step S301 because the lighting condition can be adjusted by changing the polarization direction. Operate to select polarization direction adjustment.

  Next, in step S301, when the polarization direction adjustment knob 15 is operated, the motors 21a and 21b are driven from steps S302 and S303 to simultaneously rotate the first polarizing filter 6a and the second polarizing filter 6b. Then, the polarizing filters 6a and 6b are simultaneously rotated to a position where there is no reflection on the water surface. When a desired condition is met, the operation of the polarization direction adjusting knob is stopped, and the driving of the motors 21a and 21b is stopped. As a result, the amount of reflected light can be adjusted by returning the rotation angle of the polarizing filter, and the total amount of incident light can be adjusted using the diaphragm on the lens device side.

  In this way, as a means for adjusting the amount of light incident on the image sensor, it has a pair of polarizing filters and a diaphragm, so that one can be fixed and the amount of light can be adjusted on the other according to the demand for imaging. it can. Changing the aperture changes the depth of field as well as the amount of light. By operating a set of polarizing filters, the amount of light can be reduced and reflected light can be removed. Therefore, in the case of shooting that prioritizes shooting effects in consideration of depth of field and the like, the aperture can be determined under the required shooting conditions, and the amount of light can be adjusted using a set of polarizing filters (first mode). ). Also, when you want to remove the reflections from the reflected light and avoid the whitish image to increase the contrast, align the polarization direction of a pair of polarizing filters and fix it at the rotation position to remove the reflected light, and adjust the light amount using the diaphragm (Second mode).

  When the polarizing filter is used, the transmitted light amount is reduced to 50% at the maximum. Therefore, when a transmitted light amount larger than 50% is required, the polarizing filter holding unit is retracted from the optical axis as shown in FIG. Good.

Specifically, when the filter selection switch 12 is set to the polarization filter OFF in step S101, the process goes to step S106, and the motor A (19) is energized to the position where the filter optical axis retraction position detection switch 24 is turned on, thereby polarizing filter. The holder 17 is moved. When the desired position is reached, the drive of the motor A is stopped in step S108.
In the present invention, by rotating at least one of the two polarizing filters, the angle formed by the transmission axes of the two polarizing filters (the angle between the two transmission axes when viewed from the optical axis direction) is set. The amount of light is adjusted by changing it. Here, the transmission axis is the same as the polarization direction of light that can be transmitted through the polarizing filter. In performing light amount adjustment in this way, the two polarizing filters may be rotated simultaneously in the opposite direction, or only one polarizing filter may be rotated, or the two polarizing filters may be rotated simultaneously in the same direction. Further, they may be rotated by different angles. The rotation center when rotating the polarizing filter is preferably the optical axis of the lens device, but is not limited to this, and the axis parallel to the optical axis or the optical axis (or the axis parallel thereto). May be slightly inclined (but less than 10 degrees). Further, it is desirable that the transmission axis of each polarizing filter is substantially perpendicular to the optical axis (at least 80 degrees or more, more preferably 89.5 degrees or more) in a state where these polarizing filters are inserted in the optical path.

  Hereinafter, an imaging system according to the second embodiment of the present invention will be described with reference to FIG.

Compared to the configuration of the filter switching mechanism of the first embodiment shown in FIG. 5, the filter switching mechanism of the present embodiment is different in that it has a through filter 28 made of a glass plate in addition to the polarizing filters 6a and 6b. Here, the pass-through filter has no refractive power, does not have a dimming effect, and prevents the air conversion length from changing in a state where the polarizing filter is inserted into and removed from the optical path. An optical element made of, for example, a glass plate. The pass-through filter 28 has a refractive index and a glass thickness that are substantially equal to the air-converted length of the two polarizing filters 6a and 6b. The pass-through filter 28 is held by a pass-through filter frame 29, and the polarizing filter frames 16a and 16b are rotatably held by a polarizing filter holder 30. The through-filter frame 29 and the polarizing filter holder 30 are slidably held by slide pieces 31a to 31f.
The polarizing filter holder 30 and the transparent filter frame 29 are driven by a motor C (32). The motor gear 33 fixed to the output shaft of the motor C (32) has drive pins 34a and 34b fixed to symmetrical positions with respect to the output shaft of the motor C (32).
The drive pins 34 a and 34 b are engaged with elongated holes provided in the through filter frame 29 and the polarization filter holder 30, respectively.

  In the above configuration, when shifting to photographing that does not require a polarizing filter in a state where the polarizing filter is arranged on the optical axis, the filter selection switch 12 is set to the polarizing filter OFF. When the motor C (32) is rotated clockwise in response to this command, the polarizing filter holder 30 slides on the slide pieces 31a to 31f via the motor gear 33 and the drive pin 34a and retracts from the optical axis. Accordingly, the through filter frame 29 slides on the slide pieces 31a to 31f via the drive pins 34b and is arranged on the optical axis (from the state of FIGS. 11A and 11B to the state of FIG. 11C). Transition).

  Thereby, in the case of photographing that requires a polarizing filter, the polarizing filter is disposed in the optical path, and in the case of photographing that does not require the polarizing filter, a pass-through filter is disposed in the optical path instead of the polarizing filter. In any arrangement, the optical path length can be kept constant, and the deterioration of the optical performance due to the optical path length difference can be prevented regardless of whether the polarizing filter is used.

  The imaging system according to the third embodiment of the present invention will be described below with reference to FIGS.

  In the filter switching mechanism of the second embodiment, the filter frame is linearly moved with respect to the optical path. However, the filter switching mechanism of the present embodiment is different in that it is driven in the rotational direction.

  The pass-through filter 28 is held by a pass-through filter frame 35, and the polarizing filter frames 16a and 16b are rotatably held by a polarizing filter holder 36. The polarizing filter holder 36 and the transparent filter frame 35 are driven by a motor D (37). A motor gear 38 is fixed to the output shaft of the motor D (37), the motor gear 38 engages with an idler gear 39, and the idler gear 39 engages with a gear 36 a formed on the polarizing filter holder 36. The gear 38 and the gear 36a have a gear ratio of 1: 1. The rotation direction of the gear 36a when the rotation direction of the motor D (37) is counterclockwise is the same counterclockwise direction because it is via the idler gear 39. A gear 40 is further fixed to the output shaft of the motor D (37), and the gear 40 is engaged with a gear 35 a formed in the transparent filter frame 35. The gear 40 and the gear 35a have a gear ratio of 1: 1. When the rotation direction of the motor D (37) is counterclockwise, the rotation direction of the gear 35a is a clockwise direction. That is, in the configuration of the filter switching mechanism of the third embodiment, when the motor D (37) rotates, the threading filter frame 35 and the polarizing filter holder 36 engaged with each other through a gear are rotated in opposite directions. Driven. Accordingly, when the motor D (37) rotates counterclockwise with the polarizing filter holder 36 shown in FIGS. 12 (a), 12 (b), and 12 (c) in the optical axis position, the polarizing filter holder 36 is counterclockwise. The filter frame 35 rotates clockwise and moves clockwise from the retracted position to the optical axis position (from the state of FIG. 12B to FIG. 13B). ))

  The optical axis position detection switch 41 is a switch that detects that the through-filter frame 35 is at the optical axis position, and the optical axis position detection switch 23 is a switch that detects that the polarization filter holder 36 is at the optical axis position.

  In the above configuration, when shifting to photographing that does not require a polarizing filter in a state where the polarizing filter is arranged on the optical axis as in the second embodiment, the filter selection switch 12 is set to the polarizing filter OFF. When the motor D (37) is rotated counterclockwise in response to this command, the polarizing filter holder 36 rotates counterclockwise via the gear 38 and idler gear 39, and the polarizing filter holder 36 is retracted from the optical axis. . At the same time, since the gear 40 also rotates counterclockwise, the through filter frame 35 rotates in the clockwise direction and moves to the optical axis position, and the position detection switch 41 confirms that the through filter frame 35 is at the optical axis position. Detect.

  Thereby, in the case of photographing that requires a polarizing filter, the polarizing filter is disposed in the optical path, and in the case of photographing that does not require the polarizing filter, a pass-through filter is disposed in the optical path instead of the polarizing filter. In any arrangement, the optical path length can be kept constant, and the deterioration of the optical performance due to the optical path length difference can be prevented regardless of whether the polarizing filter is used.

[Other Examples]
If a polarizing filter is used, the amount of transmitted light (of non-polarized light) with respect to the case where a pass-through filter is used falls to 50% at the maximum. However, by combining the pass-through filter and the gain adjustment (not shown) of the camera, it is possible to adjust the transmitted light amount in the above range by using the camera sensitivity instead. That is, in the region where the transmitted light amount is 50% or less, the brightness adjustment of the captured image in the region where the light amount adjustment exceeds 50% can be performed by combining the pass-through filter and the gain adjustment of the camera.

Further, by using the apparatus of the present invention, it is possible to easily perform operations such as adjusting the light amount after adjusting the polarization direction, or conversely adjusting the polarization direction after adjusting the light amount.
A combination of the aperture of the photographic lens and the light amount adjustment by the two polarizing filters may be combined and stored in accordance with the photographic scene, and the program may be called up as necessary.
Further, the two polarizing filters may be arranged as part of the taking lens, for example, at the place of the extender.

Furthermore, the effect of the present invention can be obtained even if one polarizing filter is configured on the photographing lens side and one polarizing filter is configured on the television camera side which is an image pickup apparatus and they are interlocked and controlled.
In the first to third embodiments, the electric drive using the motor as the drive source of the moving mechanism of the filter frame is exemplified. However, this may be configured to be performed manually.
In addition, the imaging apparatus (camera apparatus) includes an imaging element that can be attached and detached and receives subject light from the lens apparatus, and includes two polarizations arranged on an optical path between the lens apparatus and the imaging element. By applying the present invention to an imaging device having a filter and at least one polarizing filter of two polarizing filters, and a rotation driving means capable of rotating about an axis parallel to the optical axis. An image pickup apparatus having the above effects can be obtained.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

1 TV camera (imaging device)
2 Shooting lens (lens device)
6a 1st polarizing filter 6b 2nd polarizing filter 9 Imaging element

Claims (8)

A lens device;
An imaging device including the imaging device to which the lens device is connected and receiving subject light from the lens device;
Two polarizing filters disposed on an optical path between the lens device and the imaging device;
A rotation driving means capable of rotating at least one of the two polarizing filters around an axis parallel to the optical axis;
An imaging system comprising: The two polarizing filters are disposed on an optical axis between the lens device and the imaging device, and are held rotatably with respect to each other about the optical axis.
The rotation driving means is capable of rotating each of the two polarizing filters.
The imaging system according to claim 1. The imaging apparatus includes a color separation optical system that separates subject light from the photographing lens into color light, and an optical low-pass filter that removes high-frequency components of light incident on the color separation optical system,
The two polarizing filters are disposed closer to the lens device than the color separation optical system and the low-pass filter.
The imaging system according to claim 2. Detecting means for detecting a rotation angle of each of the two polarizing filters;
An angle difference indicating means for indicating a rotation angle difference between the two polarizing filters;
Angle indicating means for indicating the rotation angle of the two polarizing filters;
Control means for controlling the rotation angles of the two polarizing filters based on the rotation angle of the two polarizing filters detected by the detecting means and the instruction from the angle difference indicating means or the angle indicating means; ,
The imaging system according to claim 2, wherein the imaging system includes: The lens device has a diaphragm mechanism,
In the first mode of adjusting the light amount by changing the rotation angle difference between the two polarizing filters without changing the aperture value of the diaphragm mechanism, or in the state where there is no rotation angle difference between the two polarizing filters. Mode selection means for selecting a second mode for setting the angle and changing the aperture value of the aperture mechanism to adjust the amount of light;
The imaging system according to any one of claims 2 to 4, wherein: The imaging apparatus has a polarizing filter insertion / extraction means for inserting and removing the two polarizing filters at an optical axis position,
The control means adjusts the brightness of a photographed image within a range of 50% or less of the amount of incident light to the lens device, and arranges the two polarizing filters at the optical axis position by the polarizing filter insertion / extraction means, and rotates the rotation. The rotation angle difference between the two polarizing filters is changed by the driving means, and the brightness of the captured image is adjusted by the polarizing filter insertion / extraction means in the region exceeding 50% of the amount of incident light to the lens device. Removing the polarization filter of the sheet from the optical axis position, and adjusting the gain of the imaging device,
The imaging system according to claim 4.   The imaging apparatus includes a filter that is an optical element having an air conversion length that is the same as an air conversion length in the optical axis direction of the two polarizing filters, and has no refractive power and dimming action, and the transparent filter or the 2 7. A filter switching mechanism that moves one of the polarizing filters from the optical axis position to the retracted position when moving one of the polarizing filters to the optical axis position. 8. The imaging system described in 1. An image pickup apparatus having an image pickup device, wherein the lens apparatus is detachable and receives subject light from the lens apparatus,
Two polarizing filters disposed on an optical path between the lens device and the imaging device;
A rotation driving means capable of rotating at least one of the two polarizing filters around an axis parallel to the optical axis;
An imaging device comprising:

Images