JPH04263234A - Camera capable of pseudo zooming - Google Patents

Abstract

PURPOSE:To attain suitable and desired photographing corresponding to the result of distance measurement by setting the combination of the magnification of pseudo zooming and the focal distance of an optical zoom lens according to the result of distance measurement. CONSTITUTION:This camera has the optical zoom lens 21 capable of changing the focal distance, a pseudo zooming means 2 determining the magnification of the pseudo zooming, a pseudo zooming variable power optical system which is arranged in the transmitted light of the optical zoom lens, and always displays a photographing range in constant size, according to the set pseudo zooming magnification, a multipoint range-finding means 24 having plural distance measuring areas AF1-AF3 for receiving optical zoom lens transmitted light and carrying out the focus detection of the optical zoom lens at plural positions set in advance, a multipoint photometric means 36 on which photometric areas BV2, BV4, and BV5 are set at the positions corresponding to plural range-finding areas, respectively, and a zoom setting means 3 setting the combination of the magnification of the pseudo zooming and the focal distance of the optical zoom lens, by the result of the detection of the multipoint distance measuring means.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera equipped with an optical zoom function and a pseudo zoom function, and more particularly to a camera in which the ratio of both zoom functions is set appropriately.

0002

2. Description of the Related Art Conventionally, cameras have been proposed that have both an optical zoom function and a pseudo-zoom function, and enable wide-range zooming without increasing the length of the lens. In this type of camera, the optical zoom function is used first to perform zooming, and the remaining zooming is performed using the pseudo zoom function (US Pat. No. 4,652,104), and film sensitivity and subject brightness data are used. A system in which the ratio of optical zoom and pseudo zoom is set appropriately from
No. 6834) is known. The latter method effectively prevents camera shake at low brightness, which occurs in the former method, which prioritizes optical zoom.

[0003] In addition, recent cameras have further advanced automatic exposure and automatic focus (automatic distance measurement) functions that take operability into consideration, and have multi-point distance measurement and multi-point distance measurement to enable more accurate and desired camera shooting. A photometric sensor structure is adopted.

0004

[Problem to be Solved by the Invention] When the camera capable of multi-point distance measurement is equipped with both the optical zoom function and the pseudo zoom function, it becomes difficult to measure It is conceivable that a relative deviation occurs between the distance position and the photometry position, making it impossible to obtain the print photograph desired by the photographer.

The present invention has been made in view of the above, and is a pseudo-photography system that sets the ratio (combination) of both zooms based on the distance information of the subject, and allows the photographer to obtain a suitable printed photograph desired by the photographer. It provides a zoomable camera.

[0006]

[Means for Solving the Problems] The present invention provides an optical zoom lens that can change the focal length, a pseudo zoom means that determines the magnification of the pseudo zoom, and a pseudo zoom lens that is arranged in the light transmitted through the optical zoom lens and set A variable magnification optical system for pseudo zoom that always displays the shooting range at a constant size according to the zoom magnification, and focus detection of the optical zoom lens at a plurality of predetermined positions by receiving the light transmitted through the optical zoom lens. a multi-point ranging means having a plurality of ranging areas for performing
A combination of the magnification of the pseudo zoom and the focal length of the optical zoom lens based on the detection results of the multi-point photometry means and the multi-point distance measurement means, each of which has a photometry area set at a position corresponding to each of the plurality of distance measurement areas. and zoom setting means for setting.

[0007] Furthermore, it is preferable to set a combination such that the magnification of the pseudo zoom is minimized when the detection result of the multi-point distance measuring means indicates that the distance to the subject is less than a predetermined distance (Claim 2). ).

[0008]

[Operation] According to the present invention, distance measurement is performed on a predetermined position of the light flux that has passed through the optical zoom lens, while photometry is performed on a predetermined position of the light flux that has passed through the variable magnification optical system for pseudo zooming. . Then, a combination of the pseudo zoom magnification and the focal length of the optical zoom lens is set based on the distance information obtained as a result of distance measurement.

[0009] Furthermore, as the magnification of the pseudo zoom increases,
In the finder, only the distance measurement area is enlarged according to the pseudo zoom, and the deviation in correspondence between the distance measurement area and the photometry area to which the distance measurement area should correspond becomes large. When the distance information indicates that the distance is less than a predetermined distance, the combination of the pseudo zoom magnification and the optical zoom lens focal length that minimizes the pseudo zoom magnification is set, so that the above deviation is less likely to occur. .

0010

[Embodiment] Next, an embodiment of a camera capable of pseudo zooming according to the present invention will be described. Note that the camera according to this embodiment is equipped with a zoom lens whose focal length changes in the range of 35 to 105 mm, and the maximum zoom ratio by pseudo zoom (hereinafter referred to as electronic zoom) is set to 2 times. It is something. Therefore, by combining optical zoom and electronic zoom, it is possible to achieve a pseudo focal length of 35 to 210, which will be described later.
Zooming is possible within a range of mm.

FIG. 2 is a configuration diagram showing the optical system of the photographing lens and finder of the camera according to the present invention. Reference numeral 21 denotes a zoom lens that has a front group and a rear group (both not shown) inside, and the front group or the rear group moves inside the lens barrel along a guide inside the lens barrel (not shown) in the direction of the optical axis L. It is arranged to be movable, and this movement changes the positions of the front group and the rear group, thereby changing the focal length.

A main mirror 2 is located behind the photographic lens 21.
2 are arranged at an angle. This main mirror 22 is composed of a partially transmitting mirror with a transmitting part or a small hole in the center of the reflecting mirror surface, or a half mirror having a semi-transmissive mirror on the entire surface or only in the center, and is configured so that part of the light beam from the photographing lens 21 is reflected. AF module 24 via the AF mirror 23 below.
At the same time, the remaining luminous flux is guided to a finder system, which will be described later.

The AF module 24 is disposed at a position where the image passing through the photographing lens 21 forms a primary image plane, and is incident on three areas corresponding to AF areas (AF1, AF2, AF3, see FIG. 4). The distance from the subject image to the subject appearing in each area is measured using a known distance measuring method such as triangulation.

On the other hand, the light beam guided to the finder system is first guided to a focusing plate 25 as a primary image plane disposed at a position where a primary image is formed, and an image is formed on the focusing plate 25. A mark 26 indicating the AF area is on the surface of the focus plate 25.
is depicted. A secondary image of the subject is formed from the primary image onto a field frame display member 31 via mirrors 27 and 28, a relay lens 29, and a condenser lens 30. The relay lens 29 is composed of a plurality of lenses, and the image magnification is made variable by moving a predetermined lens in the direction shown by arrow A or in the opposite direction according to the specified electronic zoom ratio. be. In addition, the visual field frame display member 31
is constituted by an electro-optical element such as an LCD or an ECD, and a viewing frame 31a is formed by a light shielding portion provided at the periphery of the viewing frame display member 31.

[0015] When photographing without using electronic zoom, the entire subject image formed on the focusing plate 25 remains as it is in the field frame 3.
The image is formed on the entire surface of 1a. On the other hand, as the electronic zoom is performed, the image magnification of the relay lens 29 increases, and for example, when the electronic zoom is 2 times, an image of a range 25a shown by a broken line on the focus plate 25 is formed on the entire field frame 31a. PAN
The mode field of view frame 32 is in panoramic shooting mode (hereinafter, PAN).
The field frame display member 3 is used by entering the optical path when the camera is in a mode (referred to as a mode), and can be retracted when not in use.
1 and the PAN mode field frame 32 constitute an infinder optical system. Note that the PAN mode is a mode that creates a panoramic shooting style, and is used when obtaining a horizontally long print photo.

The secondary image on the field frame 31a is a mirror 34
is guided to the eyepiece lens 35 through which the object image is observed. The image observed with the eyepiece lens 35 can be obtained by electronic zooming, which increases the magnification of the relay lens 29, or by zooming the photographing lens 21.
When moving to the LE side, zooming is performed in the same way as when moving to the LE side. At this time, the AF area mark 26 that is displayed at the same time is drawn at a constant size on the primary image plane of the focusing plate 25, so it always appears at a constant size and position in optical zoom, while in electronic zoom Since the image is enlarged by the relay lens 29, the size and position appear enlarged according to the electronic zoom ratio (see FIGS. 4(a) to 4(c)).

The mirror 34 is a half mirror that allows a part of the light beam forming an image on the secondary image plane to pass therethrough and guides it to the photometric optical system 36. The photometric optical system 36 is composed of a photometric lens 36a and a light receiving element 36b.
6a is for re-forming an image on the light receiving element 36b. For photometry using the light-receiving element 36b, the photometry element is arranged in a predetermined area with respect to the secondary image plane so that divisional photometry is possible, as shown in FIG. 4, for example. In FIG. 3, the BV area is divided into six areas such as BV0 to BV5. In this way, the photometry area has a fixed positional relationship with respect to the secondary image plane, so it always has a constant size and position relative to the observed field of view, regardless of whether electronic zoom or optical zoom is used. . The signal received by this light receiving element is used for exposure calculation for exposure control.

The main mirror 22 and the AF mirror 23 are
It is configured to retreat from the optical axis upon receiving a release signal, and directly exposes the subject image incident from the photographing lens 21 onto a member to be photographed, such as a film or an image sensor (not shown). In addition, as will be described later, at the same time as this exposure, other necessary information such as a pseudo zoom ratio and the presence or absence of a PAN mode is written to an appropriate location outside the photographing range of the film by the EZ/PAN information writing circuit 11 (see FIG. 1), which will be described later. It is designed to be written by. If the object to be photographed is a type of camera that consists of an image sensor and records the photographed image on an electronic medium,
The EZ/PAN information writing circuit 11 may write to the electronic medium.

FIG. 1 is a system configuration diagram of a camera control system according to the present invention.

[0020] This figure is a configuration diagram when a configuration is adopted that allows both optical zooming (hereinafter referred to as OZ) using a zoom lens and electronic zooming (hereinafter referred to as EZ) using a pseudo zoom. It is also possible to use a mode (hereinafter referred to as PAN mode) in which an area obtained by cutting the top and bottom of the full screen is used as the shooting screen, and a landscape print is made to create a panoramic shooting style.

Selection of OZ mode, EZ mode or PAN mode is performed by an EZ/OZ/PAN selection switch 1. When the OZ mode or the EZ mode is selected, the zoom operation in each mode is performed by the zoom operation switch 2. EZ/OZ/PAN discrimination circuit 3
receives signals from the EZ/OZ/PAN selection switch 1 and the zoom operation switch 2, and outputs the signals to a predetermined circuit section according to the selected mode. OZ
When the mode is selected, zoom operation switch 2
The zoom lens 21 is driven so that an optical zoom ratio corresponding to the zoom operation is obtained by sending an operation signal from the zoom lens 21 to a zoom drive motor 21a that drives the zoom lens 21 (taking lens 21 in FIG. 2). When the EZ mode is selected, an operation signal from the zoom operation switch 2 is sent to the EZ drive circuit 4, and the relay lens 29 is driven so that an electronic zoom ratio corresponding to the zoom operation is obtained. . Further, when the PAN mode is selected, the selection signal is sent to the EZ drive circuit 4, so that the relay system lens 29 and the PAN mode signal are sent to the EZ drive circuit 4 to enter the relay system lens 29 and the optical path. Field of view frame 32
is driven.

The camera according to this embodiment has an auto (hereinafter referred to as AUTO) mode, and when the AUTO mode is selected, distance data from the AF position selection/distance measurement circuit 5 and distance data from the photometry circuit 6 are Depending on the brightness data, an optimal mode of EZ mode or OZ mode is selected, or zoom control is performed using a combination of EZ mode and OZ mode.

The AF position selection/distance measurement circuit 5 takes in each light reception signal at the three distance measurement positions from the AF module 24, calculates the distance measurement value for each distance measurement position, and selects a predetermined value (for example, the nearest one). ) A distance signal is output to the focus drive circuit 7 in order to select a position and focus the zoom lens 21 on the selected position. The focus drive circuit 7 outputs, for example, the number of pulses to the focus drive motor 8 in accordance with the input distance signal.

The photometry circuit 6 has a photometry area BV shown in FIG.
The respective luminance signals are taken in from the light receiving elements 36b arranged corresponding to 0 to BV5, and the AF position selection and
The selected AF position information and distance data from the distance measuring circuit 5 are taken into account to obtain a predetermined control brightness as will be described later. The photometry circuit 6 also includes a control AV/TV calculation circuit that calculates the aperture value AV and shutter speed TV from the control luminance obtained as described above. The obtained aperture value AV and shutter speed TV are then led to an aperture drive circuit 9 and a shutter drive circuit 10, respectively, and these circuits drive an aperture and a shutter (not shown) to take a photograph. Further, information regarding the selection of the EZ and PAN modes, the EZ zoom ratio, etc. is led to the EZ/PAN information writing circuit 11. These pieces of information are written by the EZ/PAN information writing circuit 11 at appropriate locations outside the photographic screen of the film at the time of photographing.

In FIG. 3, the horizontal axis represents the actual focal length of the zoom lens,
That is, it is a diagram for explaining the zoom state when the optical zoom ratio is taken as the electronic zoom ratio and the vertical axis is taken as the electronic zoom ratio. Note that the F number is also written below the actual focal length. In the figure, as mentioned above, the zoom lens 21 is 35mm/
On the other hand, the range from F3.5 to 105mm/F5.6
Electronic zoom can range from 1x (full screen shooting) to 2x. Therefore, settings can be made within the range shown by diagonal lines. For example, "OZ=35mm, EZ=2x" and "
When OZ=70 mm and EZ=1x, the shooting angle of view is the same, so the pseudo focal lengths are the same. If the pseudo focal length is fleq, fleq=OZ×EZ
...It is represented by (1).

In the above example, the pseudo focal lengths are both 70 and are equal. Due to the characteristics of zoom lenses, the open F number is F3.5 at OZ = 35mm, and OZ = 70.
In mm, as in F4.5, the larger the OZ value, the larger the open F number.

In the figure, a change in the direction of ■ is due to zooming using only the zoom lens 21, a change in the direction of ■ is due to zooming using only electronic zoom, and a change in the direction of ■ is due to zooming using only the zoom lens 21 and the electronic zoom. This shows a case of zooming in combination with zooming. Furthermore, in the figure, the plurality of lines with negative gradients each indicate an equivalent focal length line.

FIG. 5 shows a flowchart of the EZ/OZ/PAN selection routine.

In the same flowchart, "SZ" indicates the operation content of the zoom operation switch 2, and "UP" indicates the operation content of the zoom operation switch 2.
”, “DOWN”, or “NO”. “SS” indicates the selection content of the EZ/OZ/PAN selection switch 1, and “EZ”, “OZ”, “PAN”
, or "AUTO" can be selected. Further, OZTELE is the longest focal length of the zoom lens 21, and OZWIDE is the shortest focal length of the zoom lens 21. Furthermore, D is the subject distance, βeq is fle
This shows the pseudo imaging magnification expressed as q/D.

First, EZ/OZ/PAN selection switch 1
It is determined which of the PAN mode, OZ mode, EZ mode, or AUTO mode is selected (#1, #7, #10).

[0031] If “SS” is “PAN” (Y in #1
ES), sets the EZ value to 1, and generates a PAN signal to drive the EZ drive circuit 4 and the EZ/PAN information write circuit 1.
1 (#2). After this, the process moves to #3. In this mode, only the focal length of the zoom lens 21, that is, only the OZ value is changed. In other words, “SZ” is “U”
P” and the OZ value is less than OZTELE (YES in #3), follow the operating instructions for “SZ” above.
By increasing the Z value (#4) and inputting this OZ value to the zoom drive motor 21a, the zoom lens 21
is driven to the tele side. On the other hand, “SZ” is “DOWN”
And if the OZ value is OZWIDE or more (#
5: YES), the OZ value is decreased in accordance with the "SZ" operation instruction (#6), and this OZ value is input to the zoom drive motor 21a, thereby driving the zoom lens 21 to the wide side.

[0032] If “SS” is “OZ” (YES in #7)
S), it is confirmed whether the zoom lens 21 is attached (#8). Whether or not a zoom lens is attached is determined based on whether the relationship between the longest focal length OZTELE and the shortest focal length OZWIDE is OZWIDE<OZTELE. If the zoom lens 21 is attached (YES in #8), the process advances to #3 and, as in the case of "PAN", "UP" or "DOWN" of "SZ" is selected.
”The OZ value is increased or decreased according to the
Or #5, #6). This operation corresponds to the change in direction indicated by ■ in FIG. Conversely, if the zoom lens 21 is not attached but a single focus lens is attached (NO in #8)
), switch “SS” to “EZ” (#9), #11
Proceed to.

[0033] Also, if “SS” is “EZ” (#1
0 (YES), proceed to #11. In this #11, “SZ
” is “UP” and the EZ value is 2 or less (
YES at #11), E according to the operation instruction of “SZ” above.
The Z value is increased (#12), and this EZ value is input to the EZ drive circuit 4, thereby driving the relay lens 29. On the other hand, if "SZ" is "DOWN" and the EZ value is 1 or more (YES in #13), the above "
The EZ value is lowered in response to the operation instruction of "SZ"(#14
), by inputting this EZ value to the EZ drive circuit 4, the relay system lens 29 is driven. This operation is shown in Figure 3.
This corresponds to the change in the direction of ■.

0034 “SS” is “PAN”, “OZ”, “EZ”
” (NO in #10), “
Since "AUTO" has been selected, proceed to #15. With this "AUTO", the pseudo focal length fleq will be the same.
The optimum combination of Z value and OZ value is automatically set.

In this "AUTO", first, if "SZ" is "UP" and fleq<2×OZTELE (YES in #15), an increase in the pseudo focal length fleq is instructed (#16 ), conversely, “SZ” is “DOWN”
” and OZWIDE<fleq (#
17: YES), the pseudo focal length fleq is instructed to be lowered (#18). Next, the pseudo imaging magnification βeq is 1/
It is determined whether it is smaller than 100 (#19).

Here, pseudo focal length fleq, OZ value,
The EZ value and the characteristics of the camera according to this example will be explained. For example, considering the case of fleq=70,
OZ and EZ can be set between (2) OZ=35, EZ=2 and (2) OZ=70, EZ=1. When set to (2), the F-number is small and the distance measurement area is wide, making it suitable for landscape photography. On the other hand, EZ=2
As a result, image blur in printed photographs is noticeable, requiring high precision in focus adjustment, which is not suitable for low shutter speeds or low contrast. In addition, since multi-point photometry is adopted, when operating the electronic zoom, that is, the relay lens 29, as explained in FIGS. 2 and 4, the photometry area does not change, but the distance measurement area increases. Since the position changes in accordance with the electronic zoom, a shift occurs between the photometry area and the distance measurement area. Figure 4 shows the occurrence of deviation between the distance measurement area and the photometry pattern.
shows the case when EZ=1.4, and (c) shows the case when EZ=2. In (a), area BV2 accurately corresponds to area AF1, area BV4 to area AF2, and area BV5 to area AF3. However, as shown in (b) and (c) in the same figure, as the EZ value increases, only each distance measurement area is expanded, resulting in a shift in the correspondence between each distance measurement area and the photometry area. . In particular, when the selected distance measurement area and the corresponding photometry area do not correspond accurately (EZ
= 1.4, 2), exposure control is not performed appropriately, resulting in under-photos. For landscape photographs and the like (where the pseudo photographing magnification βeq is small), this deviation between the distance measurement area and the photometry area does not pose a particular problem. On the other hand, when (2) is set, OZ=70, which is the opposite of the case (2) above, and since EZ=1, no deviation occurs between the distance measurement area and the photometry area. The steps after #19 shown in FIG. 5 take the above points into consideration, and the pseudo imaging magnification βeq
When the ratio is 1/100 or less, the subject is mainly a landscape photograph, etc., and it is preferable to measure the light averagely over the entire photographic screen. Moreover, in this case, as will be described later, the deviation between the AF area and the photometry pattern becomes almost irrelevant, so it is preferable to make the F number small (that is, bright) and to make the EZ value as large as possible in order to widen the AF area. .

Then, returning to the flowchart, βeq
If <1/100 (YES in #19), proceed to #20; otherwise (NO in #19), proceed to #21. Now, if βeq<1/100, then 2×OZWI
It is determined whether DE<fleq. fleq<2×
If it is OZWIDE (NO in #20), it is determined that it is a landscape at a medium distance or a photograph of a person and a landscape, etc., and for the reasons mentioned above, the OZ value is the minimum OZWIDE.
Fixedly set to . From the above formula (1), the EZ value is f
Determined from leq/OZWIDE (#22). Also, if 2×OZWIDE<fleq (YES in #20)
S), it is determined that the photograph is a distant landscape photograph, and the EZ value is fixedly set to 2, which is the maximum value, for the same reason as described above. O
The Z value is determined from fleq/2 using the above equation (1) (#23). In this case, the zoom operation will be performed along the zoom line indicated by ■ in FIG.

On the other hand, when the pseudo photographing magnification βeq is larger than 1/100, the subject is mainly a person, etc., and backlight conditions are also possible. It is preferable to keep the value as small as possible.

Therefore, if there is a relationship of 1/100<βeq (NO in #19), then OZTELE<fleq
It is determined whether If fleq<OZTELE (NO in #21), the EZ value is fixed to the minimum value of 1 for the reason described above, and the focal length of the optical zoom (that is, the zoom lens 21) is changed to perform zooming. conduct. The OZ value is obtained from fleq/1 using the above equation (1) (#24). Also, OZTELE<fleq
If so (YES in #21), O as well for the above reason.
The Z value is fixedly set to OZTELE, which is the maximum value. From the above formula (1), the EZ value is fleq/OZTELE
(#25). In this case, the zoom operation will be performed along the zoom line indicated by ■ in FIG.

Note that in this embodiment, βeq=1/1
Around 00, the zoom line changes to ■ and ■ in FIG. 3, so the zoom lens 21 and relay lens 29 are driven greatly, but βeq = 1/1
An intermediate zoom line between the zoom lines ◯ and ◯ in FIG. 3 may be provided around 00, and this may be selected. By doing so, the amount of drive of the zoom lens 21 and the relay lens 29 can be reduced.

Next, a photometry routine in multi-point photometry will be explained using FIG. 6. First, photometry area BV0
The average value BVA of the amount of light received by each light receiving element 36b arranged at ~BV5 is determined (#30). This average value BVA is calculated when the pseudo imaging magnification βeq is βeq<1/
100, that is, in the case of a landscape photograph, etc., it is preferable to measure the light averagely over the entire photographing screen as described above. Therefore, it is next determined whether βeq<1/100, and if βeq<1/100 (YES in #31)
, #30 is set as the control brightness BVT (#32).

If βeq<1/100 (NO in #31), the selected ranging area is searched in #33. That is, in cases other than landscape photographs, etc., a photometry area corresponding to the selected distance measurement area is used. Therefore, when area AF1 is selected, area B
The brightness at V2 is replaced by brightness BVS (#34),
When area AF2 is selected, the brightness in area BV4 is replaced with brightness BVS (#35), and area AF
When 3 is selected, the brightness in area BV5 is brightness B
Replaced by VS (#36).

Next, it is determined whether there is a backlight condition. That is, the average brightness BVA and the replaced brightness B
From VS, ΔBV=BVA-BVS is calculated (#37
), it is first determined whether the obtained value ΔBV is 2 or more (#38). If ΔBV is 2 or more (Y in #38)
ES), it is assumed that there is strong backlight, and the brightness BVS is set as the control brightness BVT (#39).

On the other hand, if the value ΔBV is less than 1 (#40
(YES), it is regarded as front lighting, and the average brightness BVA is set as the control brightness BVT (#41). Also, the value ΔB
When V is between 1 and 2 (NO in #40), it is regarded as weak backlight, and the brightness in area BV1 is compared with the brightness in area BV3 (#42), and the brightness of the lower brightness is compared. value is adopted. That is, if the brightness in area BV1 is low (NO in #42), proceed to #43 (BVS+
Control brightness BVT is determined from BV1)/2 (#43)
, if the brightness in area BV3 is low (YE in #42)
S), the process proceeds to #44, and the control brightness BVT is obtained from (BVS+BV3)/2 (#44). The control brightness BVT thus obtained is then used in a calculation routine for determining the aperture value AV and shutter speed TV.

Next, the aperture value AV and shutter speed T
A routine for calculating V will be explained using FIGS. 7 to 9. Note that in the flowchart of FIG. 7, TVH indicates the camera shake limit shutter speed. This TVH is EZ=
1, in the case of standard shooting, it is approximately the reciprocal of the focal length of the photographing lens, and in the case of shooting using electronic zoom, where EZ>1,
Since the print is enlarged by twice the EZ value than standard photography, the blur caused by camera shake becomes more noticeable, so the focal length of the photographing lens x the reciprocal of the EZ value, or f
It is the reciprocal of leq. Expressing this as an apex value, T
VH=log2fleq. In addition, Fig. 9 shows the aperture value A
The program line is shown with V as the vertical axis and shutter speed TV as the horizontal axis.

In FIG. 7, first, the pseudo focal length fle
The camera shake limit shutter speed TVH for q is calculated from the above equation (#50). Subsequently, the control brightness BV
The control exposure value EVT is determined from T and film sensitivity SV (#51), and the camera shake limit shutter speed TVH is also determined.
The limit exposure value EVH is calculated from the maximum aperture value AVmin and the maximum aperture value AVmin (#52).

Next, from the pseudo focal length fleq and the open aperture value AVmin, the aperture value AV0 that can be the largest as AVmin is determined (#53). This aperture value AV
0 is determined based on the flowchart in FIG. This means that fleq is the same but the combination of OZ value and EZ value is different, for example, the above-mentioned ■OZ=35, EZ=2 and ■O
When Z=70 and EZ=1 and the brightness is the same, the same aperture value AV and shutter speed TV can be obtained, but for the photographer, without considering the combination of OZ value and EZ value,
In order to only need to consider the value of fleq, the value that gives the largest AVmin is set as AV0 among the combinations of OZ and EZ values in the currently set fleq.

In FIG. 8, first, fleq is flEZ
1 (#80), and this flEZ1 and OZT
The size is compared with ELE (#81). AVmin increases (or does not change) as the OZ value increases (EZ value decreases), so among the combinations of OZ value and EZ value, AV when EZ = 1 as much as possible.
Allow min to be set. That is, flEZ1
<If OZTELE (NO in #81), AVmin when the photographing lens 21 is OZ=flEZ1
The photographing lens 21 (ROM (not shown) built into the photographing lens)
etc.) and set it as AV0 (#82)
, when OZTELE<flEZ1 (YES in #81)
), there is no combination where EZ=1, so OZ=O
AVmin in the case of ZTELE is set as AV0 (#83, #82).

Returning to FIG. 7, from the above AV0 and the camera shake limit shutter speed TVH, the replacement limit exposure value EV is calculated.
H' is calculated (#54). Furthermore, from the above relationship,
EVT≦EVH' holds true. Next, control exposure value EV
The magnitude relationship between T, the limit exposure value EVH, and the replacement limit exposure value EVH' is determined (#55, #56).

In the region of EVH<EVT≦EVH', (#
55: NO, #56: YES), the camera shake limit shutter speed TVH is set as the control shutter speed TV (#57), and the control aperture value AV is determined from (EVT-TV) (#58).

In the region of EVH'<EVT (#55, #
56 (both NO), AV and TV increase as the luminance increases, starting from the above-determined AV0 and TVH. The increases in AV and TV are determined by the slope m, as will be described later. The slope m is preset as shown in Table 1 according to the value of the pseudo focal length fleq.

[0052]

[Table 1]

According to Table 1 above, the value of the slope m is fleq
It is set so that the shorter the fleq is, the larger the fleq is, and the longer the fleq is, the smaller the fleq is. If the brightness is TVH < the brightness that can be controlled by the TV, there is flexibility in the distribution of AV and TV, but in the case of landscapes or photographs of landscapes and people with a short pseudo focal length, the entire screen is While it is preferable to narrow down the aperture to increase the depth of field in order to sharpen the image, if there are many portraits or sports photos with long pseudo focal lengths, it may be necessary to blur the front and back of the main subject. This method focuses on the point that it is preferable to widen the aperture and increase the shutter speed in order to stop the movement of the subject. Therefore,
When fleq is short, the value of slope m is set large in order to increase the degree to which the aperture value AV increases (narrows down) in response to an increase in brightness, and conversely, when fleq is long, the aperture value AV is increased in response to a rise in brightness. In order to reduce the degree of narrowing down (narrowing down), the value of slope m is set small. By setting the slope m in this way,
An optimal combination of aperture and shutter speed can always be obtained for the pseudo focal length fleq.

Returning to FIG. 7 again, in #59, the difference between the control exposure value EVT and the replacement limit exposure value EVH' is determined as the corrected exposure value ΔEV, and in #60, the slope m is determined using Table 1 above. demand. Then, from this corrected exposure value ΔEV and the slope m, an aperture correction value ΔAV is calculated as m×ΔEV/16 (#61), and this obtained aperture correction value ΔAV
and the aperture value AV0 are added to obtain the control aperture value AV (#62). This calculation is a conversion process because the program line shown in FIG. 9 is not written in the ROM table or the like for all values of slope m in consideration of storage capacity.

Then, if the obtained control aperture value AV is below the mechanically controllable maximum aperture value AVmax (#6
3: NO), the control aperture value AV is adopted as is, and if it is greater than or equal to the maximum aperture value AVmax (#63: YES),
The maximum aperture value AVmax is adopted as the control aperture value AV (#64). Subsequently, the control shutter speed TV is determined from (EVT-AV) (#65). and,
If the obtained controlled shutter speed TV is less than or equal to the mechanically controllable maximum shutter speed TVmax (#6
6: NO), the control shutter speed TV is adopted as is, and if it is greater than or equal to the maximum shutter speed TVmax (#66: YES), the maximum shutter speed TVmax is used.
x is adopted as the control shutter speed TV, and for confirmation, the control aperture value AV is newly calculated as (EVT-TV) based on the obtained control shutter speed TV (#67). Obtained new control aperture value A
V is again compared with the maximum aperture value AVmax similar to steps #63 and #64 above (#68), and if it is less than the maximum aperture value AVmax (NO in #68), the control aperture value is AV is adopted as is, maximum aperture value AVm
If it is greater than or equal to ax (YES in #68), the maximum aperture value A
Vmax is adopted as the control aperture value AV (#69)
.

In this way, in the region of EVH'<EVT, since AV0, TVH, and m are determined only by fleq, the control AV,
The TV will be set up. Therefore, the AUT mentioned above
Even if the combination of OZ and EZ values changes depending on the subject distance in O mode, AV and TV do not change. In addition, due to the nature of the camera that the larger the EZ value and the smaller the OZ value are set, the smaller the open aperture value AVmin becomes.As a result, the larger the EZ value is set, the smaller the difference between AV and AVmin becomes. In other words, the amount of aperture from the maximum aperture increases, reducing aberrations and improving image quality, which acts in the direction of suppressing the deterioration in image quality caused by a large enlargement magnification when printing with a large EZ value. This brings about the advantage of

On the other hand, in the region of EVT≦EVH (#55
(Yes), it is preferable to make the shutter speed TV as large (fast) as possible, so set AVmin to the aperture value AV.
(#70), and the shutter speed TV is (E
VT-AV) (#71). If the controlled shutter speed TV obtained in this way is at least the minimum shutter speed TVmin, which is the mechanical limit (#72
(NO in #72), the control shutter speed TV is set as is, otherwise (YES in #72), the above TVm
in is set as the control shutter speed TV (#
73).

In this embodiment, the correspondence between the distance measurement area AF and the photometry area BV has been explained using the configuration shown in FIG. 4, but the present invention is not limited to this embodiment.
It is sufficient to have a photometry section in which each photometry area is arranged so as to correspond to each AF area of the multi-point AF section.

Moreover, the system shown in FIG. 1 uses APZ (Auto Program Zoom
) mode is also available. FIG. 10 is a flowchart of this "APZ" mode, which is executed before the EZ/OZ/PZN selection routine shown in FIG. FIG. 11 shows an APZ line diagram when a zoom lens having the characteristics shown in FIG. 3 is employed.

In FIG. 10, at #101, βT=1/
From the calculation formula (2D+46.5), an ideal magnification β value suitable for photographing a single person can be determined. For example, when D=2m, this value βT is approximately 1/50, and D=17
At a little less than m, it becomes approximately 1/80. As a result, βT is kept approximately constant compared to the conventional β, but as the distance increases, βT becomes somewhat smaller, and as the distance decreases, βT increases somewhat, which makes it ideal for people. It becomes possible to adjust the magnification β with respect to the distance near the magnification β.

Subsequently, in #102, the ideal focal length fleq is calculated from the above βT. Even if optical zoom and electronic zoom are combined, the possible pseudo focal length fleq
is limited. In the example shown in FIG.
If the fleq calculated from the above βT exceeds this value, the fleq at both ends will be a fixed value, that is, 35 mm or 210 mm. f obtained in #102
leq is adopted in the AUTO mode in the EZ/OZ/PZN selection routine shown in FIG. 5, and is distributed into EZ values and OZ values.

On the other hand, when the subject distance is extremely short, such as 1 m or less, it is not considered to be photographing a person, but is considered to be macro photography, in which a small object is photographed in a large size. In this case, it is necessary to take pictures at higher magnification as you get closer to the object, but the “APZ” mode (#101, #102
), in this area OZ=OZWIDE, E
Z=1, and the magnification becomes rather low.

In addition, recent photographic lenses include internal focusing and rear focusing zoom lenses in order to reduce the amount of lens movement during AF and speed up AF processing, and these are TELE and WI.
DE often constitutes a varifocal lens with different lens extension amounts. In the case of this varifocal lens, etc., due to the amount of lens movement, it is possible to change from WIDE to T.
Some cameras have a longer minimum shooting distance depending on the ELE. In order to be able to shoot up to the shortest shooting distance,
The shortest shooting distance Dnear that is the shortest in the range from WIDE to TELE and the actual focal length OZnear on the TELE side among the focal lengths that can be photographed at this distance Dnear are obtained from the lens (as described above, the built-in ROM in the lens unit, etc.). Extract and input as . The varifocal lens etc. are OZnear = OZWIDE, and the front lens extension etc.
If ELE and WIDE have the same shortest distance, OZnear
= OZTELE.

Varifocal lens etc., OZnear=
In OZWIDE lenses, the magnification at the shortest distance in OZTELE (hereinafter referred to as DTnear) is generally higher than the magnification at the shortest distance Dnear in OZWIDE. However, since the relationship Dnear<DTnear exists, if the subject is brought within DTnear,
If OZTELE is used, it will not be possible to focus, so it is necessary to automatically move the OZ value to the WIDE side, but in this case, a problem arises in that the magnification becomes low even though the subject is close. In this embodiment, in the APZ mode in the macro area, the subject is
In order to ensure the natural feeling that the magnification increases as m approaches Dnear, the OZ value is changed to OZWID.
Change from E to OZnear (OZnear=OZW
(If it is IDE, leave it as OZWIDE) and change the electronic zoom magnification from EZ=1 to 2 so that it can photograph up to the shortest distance Dnear and has a high magnification.

Therefore, in the second half of this flowchart, D=1 m for macro photography as described later.
The APZ line is adopted so that the increase in magnification β becomes smooth as the shortest photographing distance is reached from the state where OZ=OZWIDE and EZ=1. This will be explained below.

In #103, the obtained focal length fl
The magnitude of eq and OZWIDE is compared. fleq<
If it is not OZWIDE (NO in #103), #104
Proceed to fleq and maximum pseudo focal length OZTELE x 2
The size is compared with. If fleq>2×OZTELE (NO in #104), EZ・O in FIG.
The process moves to the "AUTO" step of the Z/PAN selection routine (#105). If fleq>2×OZTELE (YES in #104), fleq is 2×OZTELE
After being fixedly set to E (#106), the above “AUT
Move to step O''.

If fleq<OZWIDE in #103, the process proceeds to #107, where it is determined whether the subject distance D is within 1 meter. If D is 1m or more (N in #107)
O), fleq is fixedly set to OZWIDE (
#108), proceed to #104.

On the other hand, if D<1m (YE in #107)
S), as mentioned above, Dnear and OZnear are input as the shortest photographing distance information from the photographic lens (#
109). Then, from this information, the EZ value and OZ value are calculated using the formula shown in #110. That is, EZ
The value is the ratio (D-1)/(Dnear-1) (corresponding to the value 1 and how close the subject is from a distance of 1 meter).
≦1) is added so that the maximum value becomes 2 when Dnear is reached. Also, the OZ value is O
By adding the ratio proportional to the distance to the subject and the integrated value of (OZnear - OZWIDE) to ZWIDE as above, when Dnear is reached, OZnear
It is supposed to match. If the EZ value obtained in this way exceeds 2 (YES in #111)
, the EZ value is set to 2 (#112), and the OZ value is OZnea
If it exceeds r (YES in #113), the OZ value is set as OZnear (#114), and EZ・OZ・P
Exit the ZN selection routine.

FIG. 11 shows the case where a zoom lens having the characteristics shown in FIG. 5 is used, and the WIDE closest distance is 0.5 m,
The APZ line with the closest TELE distance of 1.0m is shown. D
In the area >1 m, the fl
Determine q. fleq is 35mm to 210mm, so
If the distance is less than about 2m, it is fixed at 35mm, and if it is about 17m or more, it is fixed at 210mm. If the fleq calculation result in #102 is between 35mm and 210mm,
Since there is a degree of freedom in distributing fleq into OZ values and EZ values, appropriate OZ values and EZ values can be selected from the shaded areas in FIGS. When D<1m, the nearest neighbor in WIDE is shorter, so OZnear=OZWIDE
, Dnear=0.5 is input as information from the lens (as described above, the lens built-in ROM, etc.) (#10 above)
9). When D<1m, as you get closer to Dnear, OZ
The value is fixed as OZWIDE, while the EZ value changes linearly from 1 to 2, for example. Therefore, fleq will be changed from 35 mm to 70 mm in proportion to D.

[0070]

[Effects of the Invention] As explained above, according to the present invention,
Since the combination of the magnification of the pseudo zoom and the focal length of the optical zoom is set according to the distance measurement result, it is possible to take a suitable and desired photograph according to the distance information.

[0071] In addition, when the distance measurement result is less than a predetermined distance, and there are many photographs of people, it is necessary to separately measure the main subject and the background in the distance measurement area selected by multi-point distance measurement. In such cases, the pseudo zoom is set to the minimum to minimize the discrepancy in the correspondence between the distance measurement area and the photometry area, allowing for proper backlight detection. It is possible to provide the photograph that the photographer expects.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of a camera control system according to the present invention.

FIG. 2 is a configuration diagram showing an optical system of a photographing lens and a finder of a camera according to the present invention.

FIG. 3 is a diagram for explaining a zoom state when the horizontal axis represents the actual focal length of the zoom lens, that is, the optical zoom ratio, and the vertical axis represents the electronic zoom ratio.

FIG. 4 shows the occurrence of deviation between the distance measurement area and the photometry area.
) shows the case when EZ=1.4, and (c) shows the case when EZ=2.

FIG. 5 shows a flowchart of an EZ/OZ/PAN selection routine.

FIG. 6 shows a flowchart of a photometry routine in multi-point photometry.

FIG. 7 shows a flowchart of a routine for calculating an aperture value AV and a shutter speed TV.

FIG. 8 shows a flowchart of a routine for calculating an aperture value AV0.

[Figure 9] The vertical axis is the aperture value AV, and the shutter speed TV
This shows the program line when the horizontal axis is .

FIG. 10 shows a flowchart of APZ mode.

11] With the zoom lens shown in FIG. 5, WIDE nearest 0.
5m, TELE closest 1.0m APZ line is shown.

[Explanation of symbols]

1 EZ/OZ/PAN selection switch 2 Zoom operation switch 3 EZ/OZ/PAN selection circuit 4 EZ drive circuit 5 AF position selection/distance measurement circuit 6 Photometry circuit/control AV. TV calculation circuit 7 Focus drive circuit 8 Focus drive motor 9 Aperture drive circuit 10 Shutter drive circuit 11 EZ/PAN information writing circuit 21 Photographing lens (zoom lens) 21a Zoom drive motor 22 Main mirror 23 AF mirror 24 AF module 25 Focus plate 25a Field of view during pseudo zoom 26 Range measurement area marks 27, 28, 34 Mirror 29 Relay lens 30 Condenser lens 31 Field frame display member 31a Field frame 32 Field of view frame for PAN mode 33 In-finder optical system 35 Eyepiece system lens 36 Photometry Optical system 36a Photometric lens 36b Light receiving elements AF1 to AF3 Distance measurement area BV0 to BV5 Photometry area

Claims (2)

[Claims] 1. An optical zoom lens whose focal length can be changed; pseudo zoom means for determining a magnification of pseudo zoom;
a variable magnification optical system for pseudo zoom that is placed in the light transmitted through the optical zoom lens and always displays the shooting range at a constant size according to the set pseudo zoom magnification; A multi-point distance measuring means having a plurality of distance measuring areas for performing focus detection of the optical zoom lens at a plurality of predetermined positions, and a photometry area set at a position corresponding to each of the plurality of distance measuring areas. A camera capable of pseudo zooming, comprising: multi-point photometry means; and zoom setting means for setting a combination of a pseudo zoom magnification and a focal length of an optical zoom lens based on the detection results of the multi-point distance measurement means. 2. The zoom setting means sets a combination that minimizes the magnification of the pseudo zoom when the detection result of the multipoint ranging means indicates that the distance to the subject is less than or equal to a predetermined distance. A camera capable of pseudo zooming according to claim 1.