JPS626232A - Camera system with preview mechanism - Google Patents

Abstract

PURPOSE:To perform accurate exposure arithmetic at any time even during the operation of a preview mechanism by correcting the arithmetic result of an arithmetic means on the basis of stored lens information and current lens information when it is decided that the preview mechanism is in operation. CONSTITUTION:When an AE lock is made during the operation of the preview mechanism, the deviation DAvz of a zoom FNo at the moment when the AE lock is made is stored as AE lock deviation DAvx1 and a shutter speed value Tv calculated by using the difference from the deviation DAvz after the completion of zooming is corrected to correct the shutter speed value Tv by variation in F value due to the zooming, thereby holding exposure control proper. Further, a stop-down light measured value is not used for open-aperture light measurement arithmetic, so when the operation of the preview mechanism is reset while the AE lock is made, light is measured at open aperture again after the preview resetting and the result is stored.

Description

Detailed Description of the Invention - No. 1 The present invention relates to a camera system that performs TTL photometry, such as a 7-lens camera, and particularly has a preview mechanism that narrows down the aperture of a photographic lens attached to a camera body to a predetermined aperture value. Regarding the camera system.

[Koriba Ran] Until now, there has been no known camera system that is equipped with the above-mentioned preview mechanism, performs TTL aperture metering while the Brevigny mechanism is in operation, displays the appropriate shutter speed, and controls exposure based on this shutter speed. ing.

In such a camera system, when the so-called AE lock is activated, which stores the photometric value at the moment of manual operation while the preview mechanism is operating, the photometric value at the moment of manual operation is stored. , an appropriate shutter speed is calculated based on this photometric value.

However, in such a system, if a zoom lens whose focal length can be changed is used as the photographic lens, if zooming is performed with the AE locked while the camera shake mechanism is operating, the aperture value will change due to zooming, so the film While the amount of light incident on the surface is also changed, the shutter speed calculated for AE lock is not changed. Therefore, an exposure error will occur.

Therefore, an object of the present invention is to provide a camera system that does not cause such exposure errors.

In order to achieve the above object of determining σ, the present invention provides a camera system having a preview mechanism that narrows down the aperture of a photographic lens attached to a camera body to a predetermined aperture value, in which the preview mechanism is manually activated. A preview means to be operated, a determining means for determining whether or not the preview mechanism is activated, a lens information output means for outputting lens information regarding the photographic lens, and a photometer for measuring subject light transmitted through the photographic lens. a photometry means, a calculation means for calculating an appropriate shutter speed according to the photometry result of the photometry means, an AE lock means for storing the photometry result at the time of manual operation, and a lens when the AE lock means is activated. Based on the lens information storage means for storing information and the current lens information and the lens information stored in the lens information storage means when it is determined by the determination means that the preview m structure is in operation. The present invention is characterized in that it has a correction means for correcting the calculation result of the calculation means.

Sakuji J1 Therefore, according to the present invention, during the operation of the Brevigny mechanism, the AE
Even if zooming is performed after locking, the exposure calculation can be corrected according to the change in aperture value caused by zooming, so that accurate exposure calculation can always be performed even while the preview mechanism is operating.

(The following is a blank space) Actual W Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

First, in FIG. 14, (A) is a graph showing the relationship between the aperture value (F value) and the output (Pa) of the photometric cell when a reference lens prepared in advance is attached.

If adjustments have been made for automatic exposure control, the vertical axis also corresponds to the automatically set shutter speed (S, S,).

On the other hand, (B) shows the output of the photometric cell (
This is the appropriate line when the aperture value (F value) and the aperture value (F value) are adjusted to have a linear relationship, and also corresponds to the shutter speed when the reference lens is attached. Comparing (A) and (B), they match when the aperture is open, but
There is a difference when the aperture is narrowed down. That is, this is
This means that when an aperture value other than wide open is set, the shutter speed value automatically set based on the aperture photometry result is different from the shutter speed value automatically set based on the photometry result during preview.

Therefore, in the embodiment of the present invention, a certain constant value ΔPv is subtracted as a preview correction amount from the output of the photometry cell during the preview Pf & the adjustment operation (actually, the exposure value Ev calculated based on this), and the preview Display when the mechanism is operating
It is configured to minimize exposure control errors. The result of this correction according to this embodiment is shown in FIG. 14 as a curve (C).

Furthermore, (D) in Figure 14 shows the aperture value (F value) and the output of the photometric cell (when an interchangeable lens with an open F value of 2.8 is attached)
It represents the relationship with P a). Normally, the cell output (P a) in aperture photometry when an interchangeable lens is attached differs from that when the above-mentioned reference lens is attached by an aperture photometry error Wvi. Therefore, when an interchangeable lens is attached, accurate exposure control cannot be performed unless the aperture photometry error W vi is corrected. Therefore, in the present embodiment, this is corrected to perform automatic exposure adjustment with full-open metering, and the corrected result is shown in FIG. 14 (E).

However, this aperture photometry error W v i appears in i44 when the aperture is open, but it decreases when the aperture is stopped down (that is, when the aperture is stopped down, the variation in cell output due to lens exchange is reduced. Therefore, in this implementation In the example, when using wide-open photometry, the wide-open photometry error W v i (7)
While the preview mechanism is in operation, although the Brevigny correction amount ΔPv is corrected, the closed-air photometry error W
The configuration is such that no correction of vi is performed.

In FIG. 14, (F) shows the result of correcting the above-mentioned preview correction amount ΔPv using an interchangeable lens with an F value of 2.8 that has the aperture-linked characteristic of CD) as described above. . Looking at this, it is considered that it is better to correct the aperture photometry error W v i because it exists in the aperture open state, and not to correct the Brevigny correction amount ΔPv.

Also, create a preview mechanism! In a camera that stores the aperture value at 1J in its memory, when the battery is removed, the contents of the memory are erased, so even if the battery is installed next time, the correct aperture value cannot be displayed. Furthermore, if you change the lens while the preview is still active, and the aperture diameter of the newly installed lens is different from that of the removed lens, the aperture diameter will be different even if the aperture preset lever position remains the same. The aperture value you use will be useless. Also, when the Preview Ifi mechanism is activated, the aperture preset lever on the camera body moves and stops when the predetermined number of aperture steps is reached, but the aperture f-number may change when changing lenses. Because of this, even if the replaced and installed lens is stopped down from its wide open aperture to the same number of steps as the removed lens,
The aperture value may be different from the preview aperture value of the removed lens.

Therefore, in this embodiment, if the battery or lens is removed even once, a message indicating that the lens is not attached is displayed to warn the camera user. There is.

Furthermore, when a zoom lens whose open F value changes according to zooming is attached, if you zoom with the preview mechanism activated, the F value will change according to zooming, and the display of the fringe value will also change7. In this example, the aperture r) amount (hereinafter referred to as zoom FNo deviation) that changes due to zooming when the preview mechanism is activated is calculated as DA vz1 preview. If the F value when the mechanism is activated is A V pv (hereinafter referred to as the Brevigny F value), perform the calculation Avpv - DAvz = PAv (1) and store this PAv in the memory as the Brevigny aperture storage amount. The aperture value Av that is stored and displayed when the preview mechanism is activated is PAV+DAVZ:AY...(2) By performing the calculation and displaying the F value according to this value Av, the zoom FNo @ difference DAvz is calculated by zooming. The aperture value A displayed when the preview mechanism is activated corresponds to the change in the aperture value A.
The configuration is such that v can also be changed.

Also, if the apex value of the sensitivity of the loaded film is Sv, the apex value of the subject brightness according to the output of the photometry cell is Bvs, and the apex value of the calculated shutter speed is Tv, then the exposure while the preview mechanism is operating is Since the calculation is a narrowing down calculation, the shutter speed Tv determined by the calculation is Bvo+5v=Tv, where Bvo is the subject brightness according to the output of the photometric cell.
(3), so by zooming F
The subject brightness value Bvo also changes by the amount that the value changes, and this changes the shutter speed value T'v determined by calculation.

However, if the AE lock is activated while the preview mechanism is operating, the subject brightness at the moment the AE lock mechanism is activated is
Since TL photometry is performed and stored, even if zooming is performed afterwards and the F value changes and the amount of light on the film surface changes, the subject brightness value Bvo used for calculation will not change. Therefore, even if zooming is performed, the shutter speed value Tv determined by calculation does not change, so that appropriate exposure control is not performed. Therefore, in this embodiment, if the AE lock occurs while the preview mechanism is operating,
Zoom FNo deviation DAvz at the moment of AE lock is A
By storing the E-lock deviation DAvz and correcting the shutter speed value Tv calculated by taking the difference from the deviation DAvz after zooming is completed, the shutter speed value Tv can be adjusted by the amount that the F value has changed due to zooming. The exposure is corrected to maintain proper exposure control. Expressing this in the formula: Bvo+Sv+(DAvz+DAvz)=Tv...
・(4) The shutter speed value T obtained from equation (4) becomes
It is configured to perform display and exposure control using v.

Furthermore, when the aperture F value of the attached lens is AVO2, and AE lock is performed in the aperture metering state, Bvo+Avoz+5v=Ev=Tv+Av...(5
), that is, the TTL measurement value By in the stop-down photometry state is stored.

(B v = B vo + A voz) However, when the preview mechanism is activated, Bvo + 5v = Tv
6 @ @ Since the aperture calculation is performed as in (6), if Bvo in the open metering state, that is, the cell output through the aperture in the open state, is stored, equations (5) and (6)
As is clear from the comparison with the equation, an error occurs in the shutter speed value by an amount corresponding to the difference between the aperture value Ay and the open F value A voz when the preview mechanism is activated.

Therefore, in this embodiment, the operation of the preview mechanism is prohibited while the AE lock is in operation, so that the open photometry value is not brought into the narrowing down calculation while the preview mechanism is in operation. However, in addition to the above, when the preview mechanism during the AE clock is activated, the light may be re-metered after narrowing down and the measured value may be stored.

*Furthermore, if the AE lock is performed while the preview mechanism is operating, the cell output through the embossed pattern will be stored, and if this value is used in the open photometry calculation after the preview is released, an error will occur. Therefore, in this embodiment, in order to prevent the aperture photometry value from being brought into the aperture photometry calculation, the AE lock is applied.
- When the operation of the preview mechanism is canceled, the camera is configured to carry out open metering again after canceling the preview and store the result.

First, FIG. 1 is a top view of a camera body according to an embodiment of the present invention, and FIG. 2 is a front view thereof. The camera of this embodiment has the following modes: aperture-priority automatic shutter speed control mode, shutter speed-priority automatic aperture control mode, program automatic exposure control mode, and manual exposure control mode. The speed can be adjusted up or down by moving the setting lever (A S ) in the direction indicated by (X) in FIG. 2. The set aperture value and shutter speed are then displayed on a liquid crystal display (LCD).

(AEL) is an AE lock button that can be manually recovered. When this AE lock button (A F L ) is pressed, the TTL photometry value at that time is stored in the memory inside the camera body, and a so-called AE lock is performed. Ru.

(RB) is a shirt release button. (PB)
is the preview button that is energized to return to the position shown, and this preview button (PB) is once pressed to the second position.
When pressed in the direction of the arrow (Y) in the figure, the preview mechanism is activated and the aperture is narrowed down to the set aperture value.
) is released, the preview mechanism is deactivated and the aperture is returned to its open state.

3(A), 3(B), 3(C), and 3(D) are diagrams each showing the display mode of the liquid crystal display device (LCD) of this embodiment in the aperture-priority automatic shutter speed control mode. Figure (A) shows the display mode when photometry is not being performed, and Figure 3 (B) shows the display in the normal open metering state where the preview mechanism is not activated! ! At this time, the set or calculated aperture value and shutter speed value are displayed as shown in the figure.

Figure 3 (C) shows the display mode during aperture metering when the preview mechanism is activated;
Similarly to B), the set aperture value and the calculated shutter speed value are displayed, and the F'' mark indicating the aperture value disappears at regular intervals. Figure 3 (
D) shows the display state when the lens or battery is removed even once while the preview mechanism is operating, and neither the aperture value nor the shutter speed value is displayed, and only the "F" mark flashes. .

FIG. 4 shows the electrical circuit of the camera of this embodiment having such a configuration. In order to simplify the explanation below, only the operation in the aperture-priority automatic shutter speed control mode or manual exposure control mode will be explained. In the same figure, (
μC) is a control microcomputer that controls all sequences related to camera exposure control, and (I P,) - (I
P, ) are all its input ports. (CL R) is the reset terminal of the control microcomputer (μC), and this terminal (
CLR) rises, the control microcomputer (μC) executes a predetermined program from the beginning. The resistor (RO) constitutes a power-up clear circuit together with the capacitor (Co), and when the control microcomputer (μC) is connected to the power supply, the terminal (CLR) is momentarily set to "L". All resistors other than the resistor (Ro) are pull-up resistors.

(LM) is a photometering section, which transmits a photometric value of the subject light transmitted through the photographic lens to the control microcomputer (μC). (
LR) is a ROM (Read
0nly Memory), and transmits lens information, which will be described later, to a control microcomputer (μC).

(FR) is a DX code reading section which reads film sensitivity information electrically written on the cartridge of the loaded film and transmits it to the control microcomputer (μC).

(μA) is an AF microcomputer for automatic focus adjustment of the photographic lens, and performs measurement and lens drive control.

(1, D) is the lens drive unit, and the AF microcomputer (μA
) to drive the photographic lens under the control of

(AC) is an aperture control section, which performs narrowing control of the aperture during shirt release or previewing. (S p
vz) is an aperture detection switch, which is closed when the aperture is driven, and is opened when the preview is released by pressing and releasing the preview lever (PB), or when the charge of the preset system is completed by winding after release. It is configured as follows.

Controls the up/down of the mirror during tally release and the first and second curtains of the 7-ocal brain shutter.

(S4) is a winding completion detection switch, which is configured to be opened when winding of the film is completed and closed when the second curtain of the shutter completes running. (DS) is a display section, which displays a preset aperture value and a shutter speed value calculated according to the photometry result using a liquid crystal display device ('LC'D) shown in FIG.

(Spv+) is a preview activation switch that is closed by pressing the preview lever (PI3), (SAEL) is AE
AE closed by locking button (AFL) suppression
The lock switch (S,) is closed by pressing the shirt release button (RB) to start the automatic focusing operation by the AF microcomputer (μA).
The i start switch (S2) is the shirt release button (R
This is a release switch that is closed by pressing B).

The above four switches (S pvl) (S 8EL) (S
1) (S 2) D data) (AN) is connected to the input. The output of AND day) (AN) is used as the photometry start signal (S
If even one of the four switches mentioned above is closed, the photometry start signal (SWON) becomes "L".

(OR) is an OR date, one input is from the preview activation switch (Spv+), and the other input is from the AE flow switch (Sl) V2) to the inverter date (IN).
connected via. This is because the preview mechanism is not activated when the AE flock switch (Spv2) is closed, that is, when the aperture is narrowed down and the film winding is not completed after the shirt release. This is because the switch (Spv+) is not connected to the control microcomputer (μC). (S au)
(S ad) are switches that are opened and closed in conjunction with the setting lever (A S ) to increase or decrease the aperture setting value, and when closed, change the fringing setting value. be able to.

When the power source is attached to the camera, the control microcomputer (μC) executes the program from the beginning. FIG. Explain the operation of the example.

First, when the battery is installed, the control microcomputer (μC) initializes all ports and RAM in step #1. At this time, the preview aperture storage fi P A v is set to '0'' in order to display the aperture value to indicate that no lens is attached. The current zoom FNo deviation DA from the aperture value Av to be controlled
The value obtained by subtracting vz is stored as the preview aperture storage amount PAv. Then, when displaying, this preview aperture save 'xP A v and the current zoom FNo deviation D
Avz is added and the value is displayed as the aperture value Av. Thereby, even if the aperture is fixed while the preview mechanism is in operation, the display of the aperture value can be changed by zooming. Also, at this time, save the preview aperture ji P
If Av is set to "0", the aperture value Av displayed as described later will be "0" and the aperture value will be displayed as shown in Figure 3 (
D).

When the battery is installed, the preview aperture is saved iP.
Since the memory of Av has been lost, this preview aperture storage amount PAv is initially set as "0", and the display shown in FIG. 3(D) is made when the preview mechanism is in operation. Next, in step #2, the photometry start signal (SWON) is monitored and it is determined whether any of the four photometry start switches is "ON". At this time, if all four photometry start switches mentioned above are "OFF", #3
Go to , turn off all the displays, then return to #2 and wait for the photometry start signal (SWON) to turn "ON".

On the other hand, in step #2, the photometry start signal (SW'ON) is
ON”, proceed to step #4 and start metering. Then, in step #5, it is determined whether the preview m structure is in operation, and in step #6, the DX code reading section (FR) reads the If there is a DX hood signal, it is converted to the film sensitivity apex value Sv, and if there is no DX code signal, rsO=100 is stored as the Sv value.

Next, in step #7, the attached lens ROM (L
Information about the lens's aperture FglAvozW is input from R), and automatic focus adjustment operation is performed in step I8.

Then, in step #9, the up/down switch (S
au) (S ad) and determines the aperture setting value A vSET.Next, in step #1o, the microcomputer (μC) uses the above information and the photometry input from the photometry section (LM). Exposure calculation is performed based on the value By, and the shutter speed value Tv for control is determined.
and the aperture value Av are determined, and in step #11 this is displayed using the liquid crystal display device (LD) of the display section (D S ). After that, in steps #12 and #13, the state of the switch (S,) (S2) is determined, and if the film winding is completed and the switch (S2) is "ON", the AF is activated in step #14. The automatic focus adjustment operation by the microcomputer (μA) is stopped, and exposure control is performed using the shutter speed value and frit value determined in step #15.

Next, in step #16, the setting state of the switch (SAEL) is determined, and if the AE flock button (AFL) is set to medium and the switch (SAEL) is ON, step #1
At 8, the AE clock flag (
AELF). In step #16 switch (
SAEL) is “OFF”, A in step #17.
The E-flock flag (AELF) is reset, and the state of the switch (Spv+), which is closed when the preview button (PB) is pressed in step #19, is determined. Here, during the AE clock, the process proceeds from step #16 to step #18 and does not pass through step #19, so the operation of the preview mechanism is prohibited.

If the switch (SpV+) is "ON" in step #19, the automatic focus adjustment operation is stopped in step #20, and the process proceeds to step #21, where preview imprint control is performed. At this time, in this embodiment, the current χ-mm FNo deviation DAvz is subtracted from the aperture value Av to be previewed to obtain the preview aperture storage amount PAv. In this embodiment, the preview mechanism 81 uses exactly the same mechanism as the aperture mechanism used for shirt release, so if the film winding is not completed and the aperture preset system is not charged, the preview mechanism must be activated. I can't. In this case, as mentioned above, since the switch (SpV2) is "ON", the switch (Spv+) is disconnected from the control microcontroller (μC) due to the OR date, so the switch (S, pv+) Even if the setting state of is determined, useless preview control is not performed.

Next, the microcomputer (μC) determines the photometry start signal (SWON) in step #22, and if any of the four photometry start switches is ON'', it starts a 10-second timer in step #23. Reset and start. This timer is provided to maintain the photometry state for 10 seconds even if the four photometry start switches are released.

Then, in step #24, the count status of this timer is determined, and if the 10 second count is not completed, the process returns to step #5 to continue photometry, and if the 10 second count has been completed, the process proceeds to step #25. The photometry is stopped, the process returns to step #2, all the displays are turned off in step #3, and the process waits for one of the four photometry start switches to be turned on.

FIG. 6 shows preview determination II of step #5 in FIG.
This is a flowchart. To explain this preview determination 70-, first, in step #26, switch (
S, ) is determined, and if the film winding is not completed and the switch (S4) is "ON", step #
32, the preview flag (PVF) indicating that the preview mechanism is in operation is reset. This is because the film winding has not been completed after the shirt release, so this cannot happen during preview. Even if the shirt release is performed in the preview state and Brevigny is subsequently released, the process proceeds to step #32 and the preview flag (PVF) is reset. When the switch (S, ) is "OFF" in step #26, the setting state of the switch (S9V2) is determined in step #27, and if the switch (Spvz) is "ON", it is in the narrowing down state, so step #28 Set preview 7 lag (PVF) with switch (SpV2)
If it is "OFF", the process proceeds to step #29 and the setting state of the switch (Spv+) is determined.

Here, in step #27 switch (Spvz) Q'”
OFF” and the switch (Spv+) is turned off in step #29.
ON", the preview lever (PB) has been pushed down a little to start the preview mechanism, or after the preview lever (r'B) has been pushed down deeply to cancel the preview and the preset system has been recharged (this The switch (S9V2) is turned OFF"), or the preview lever (PB) is in the process of returning upward, so from step #29, proceed to step #6 in Figure 5 and do nothing. No, if the switch (Spv+) is OFF in step #29, then step #3
0 determines the set state of Brevigny 7 lugs (PVF).

Here, if the preview flag (PVF) has been reset, the switch (S4
) is "○F is", switch (S pvz) is OFF",
The switch (Spv+) is in the "OFF" state, that is, the winding of the film has been completed and there is no preview operation at all. At this time, you can proceed to the next step without doing anything, but in this embodiment, no problem will occur even if the preview flag (PVF) that was originally reset is reset again, so for convenience, proceed to step #32. The preview flag (PVF) has been reset again.

Next, in step #30, the preview flag (P V F
) is reset, switch (S4)
Considering that (Sl)V2)(SRIV'l) are all "OFF", this preview judgment routine is executed for the first time after the preview mechanism is deactivated. At this time, the AE
In case you are in a pinch, set the AE block 7 lag (AE L F) in step #31 and prepare for re-metering, then set the preview flag (PVF) in step #32. ) to reset.

FIG. 7 is a 70-chart showing the detailed operation of the DX code input step of step #6 in FIG. First, in this 70-, the film sensitivity value Sv is set to l5O = 100 equivalent in step #33, and the DX
D related to film sensitivity from the hood reading section (FR)
Read the X code, then step #35'C''
Determine whether there is a DX code. At this time, if there is no DX code, this routine is skipped as is, and therefore the film sensitivity ASv remains at l5O=1'00.

If there is a DX code in step #35, it is decoded in step #36 and the film sensitivity value Sv is rewritten.

FIG. 8 is a flowchart showing the detailed operation of the lens information input step of step #7 in FIG. In this flow, first, in step #37, it is determined whether or not the photographing lens is attached to the camera/labor body. If the lens is attached, the process proceeds to step #38, and the lens ROM (
'LR), open F value Avo, minimum F value A vmax,
Zoom FNo deviation DAvz and open photometry error Wv
Enter i.

Next, in step #40, add the aperture F value Avo transmitted from the lens and the zoom FNo deviation DAvz, and set this as the calculated aperture aperture Avoz indicating the aperture F value at the current zooming position. , the minimum F value A vmax and the zoom F Nol difference DAvz are added, and this is calculated as the calculated minimum F value ^vm indicating the minimum F value at the current zooming position.
Let it be axz. Then, in step #41, the setting state of the AE flock flag (AE L F ) is determined, and if the AE flock flag (AE L F ) is reset, that is, if the AE flock flag is not in the AE flock state, the setting state of the AE flock flag (AE L F ) is determined. Then, the current calculation aperture F value Avoz and zoom F
Noi difference DAvz is Avoz+, DAvz, respectively.
Close and save each. Therefore, Avoz+, and D
Avz, will no longer be updated when AE flocked, and AE
Performance W when the flock button (A F L ) is pressed,
ry1 release F value AVOZ% and zoom FNo deviation DAv
z will be stored respectively.

The reason why the calculated open F value Avo'z is memorized when the -A E lock is achieved in Uni is that the subject brightness By is the sum of the subject brightness Bvo during full open metering and the calculated open F value A VOZ. Therefore, considering that the aperture F value changes due to zooming during aperture metering, the exposure control amount may change if only the subject brightness Bvo during aperture metering is stored using the AE block. Furthermore, the reason why the zoom FNo deviation DAvz is stored by the AE block is to prevent the exposure control amount from changing when zooming is performed during the AE block when the preview mechanism is in operation, as described above.

Next, in step #43, the preview flag (PVF)
If it is set, proceed to step #44, and as described above, Wvi is set so that the wide open photometry error Wvi is not corrected while the preview
is set to "0", and in order to perform the narrowing down calculation, the calculation open F value A voz% Avoz + q and the minimum F value for calculation
The values A vmaxz are each set to 0''.

In addition, if it is determined in step #37 that the lens is not attached, the process proceeds to step #39, and as described above, if the lens is removed even once while the preview mechanism is operating, the aperture value is displayed. In order to make the image as shown in Fig. 3(D), set the preview aperture storage i1 P A v to "0", and set the zoom F to perform the aperture calculation.
Nog4 difference DAvz, DAvz.

are respectively set to 0'', and the above-mentioned step #44 is performed.

FIG. 9 is a 70-chart showing the detailed operation of the automatic focus adjustment step of step #8 in FIG. First, in this flow, the preview flag (PV
F ) is determined, and if it is in the reset state, that is, the preview mechanism is not in operation, proceed to step #46, and determine the setting state of the switch (Sl), and if the switch (Sl) is "ON", step #47 own rf4h
Start the focus adjustment mechanism and press the switch (S,).
is “OFF”, proceed to step #48 and autofocus side W1! ! ! Stop LJ production.

Further, if the preview flag (PVF) is set in step #45, that is, if the preview mechanism is in operation, no automatic focus adjustment operation is performed. This means that since the automatic focus adjustment operation has already been stopped when the preview mechanism is started, the automatic focus adjustment operation will not be performed even if the switch (S, ) is turned ON while the preview mechanism is in operation.

FIG. 10 shows the detailed operation of the photometric value manual calculation step in step #10 of FIG. 5.
It is. In this 70-, first, in step #49
The set state of the E lock flag (AELF) is determined, and if this flag is in the reset state, that is, if the AE lock is not in progress, the open photometry value Bvo is input in step #50.

Next, in step #51, B vo, A VOZ+, S
v.

and Wvi are all added to obtain the exposure value Ev.

Then, in step #52, the set state of the Brevigny 7 lug (PVF) is determined, and if this flag is in the set state, that is, the preview mechanism is operating, step #53
Add the difference between DAvz and DAvz to the above Ev,
The exposure value Ev is corrected by eliminating the correction amount ΔPv. Here, the reason for adding the difference between D A vz + and DAVZ is to prevent the exposure control amount from changing even if zooming is performed with AE lock while the preview mechanism is operating, as described above. The reason why the preview correction amount ΔPv is subtracted is to correct the exposure control amount so that it does not change between aperture metering and aperture metering because the aperture interlocking characteristics of the TTL photometry cell output are poor.

Here, although the preview correction amount ΔPν is set to a constant value in this embodiment, it is not limited to this.
The preview correction amount ΔPv may be a variable amount. For example: 1. As shown in FIG. 14, if the preview correction amount ΔPv is set to a constant value, the preview correction amount ΔPv is increased or decreased depending on the preview aperture value because the preview state near the open aperture state results in excessive correction.

2. Since the aperture-linked characteristics of the output of the photometric cell differ slightly depending on the type of photographic lens, the preview correction amount ΔPv is stored in advance in the ROM of each photographic lens, and the preview correction amount differs for each lens. ΔPv is used.

3. Combine 1.2 above.

4. If the number of stops from the open aperture value due to the preview is within a predetermined number of steps (for example, within 0.5 Ev), the preview correction amount ΔPv is corrected.

This configuration may also be used.

For example, in the case of 4 above, using X shown in the following formula,
If X is less than 0.5, set the preview aperture correction amount ΔPv to "0", and only if X is 0.5 or more, step #53
As is clear from the fact that it is sufficient to provide a step to advance to
i exists, so in this case, only this wide open photometry error W v i is corrected, and the preview correction amount ΔP
Exposure calculation errors can be further reduced by not correcting v. In order to configure in this way, first find the value Y shown by the following formula, Y=PAv-Avo...
・(8) If this Y is 0'' between step #52 and step #53 in FIG. 10, the preview correction amount ΔPv
0", and if Y is other than 0", proceed directly to step #
All you have to do is add a step to step 53.

Step #54 determines whether the camera body (taking lens) is attached, and #55 determines whether the preview 7 lug (PVF) is set, and if no lens is attached. When the preview I hole structure is in operation, proceed to step #57 and set the 7-cumulator (Ace).
) is set to "θ", and the lens is attached and the preview mechanism is not operating (preview flag (P V F
) is in the reset state), the threshold value A vSET set in step #56 is substituted into the accumulator (Acc).

Then, in step #58, the value of the 7 cumulator (AcC) is set to Av, and the 7 cumulator (A
ce) is subtracted to obtain the shutter speed value Tv. Next, in step #59, the preview flag (P V F
) is determined, and if the preview mechanism is in operation, the current zoom FNo deviation DAvz is added to the preview aperture value PAv in step #60 to obtain the calculated aperture value Av. This is because, as described above, the frit value displayed while the preview mechanism is in operation is changed and displayed in accordance with zooming. Aperture value AvB found here
Exposure display and exposure control are performed using the shutter speed value Tv and the shutter speed value Tv.

FIG. 11 is a flowchart showing the detailed operation of the display step of step #11 in FIG. First, in this flow, in step #61, the aperture value Av and shutter speed value Tv obtained by the calculation routine shown in FIG.
It is set in a register to be transmitted to the display unit (D S ) as display data. Next, in step #62, the set state of the preview 7 lag (P V F') is determined, and if this flag is in the reset state, that is, the preview mechanism is released, proceed to step #63, and
The data to prevent the F'' mark from blinking is displayed on the display (
DS).

In addition, if the preview flag (PVF) is set in step #62, that is, the preview mechanism is in operation, data for making the F" mark blink in step #64 is displayed on the display ( Then, in step #65, the preview aperture storage amount PAv is determined, and if the preview aperture storage amount PAv is 0'', the process proceeds to step #66 and the display section (DS) is set. The aperture value data to be transmitted is set to "0".

This is because if the preview mechanism is operating and the preview aperture storage fi P A v is "0", it means that the lens was removed once or the battery was removed while the preview mechanism was operating and the aperture was stopped down. This is to make the aperture display as shown in FIG. 13(D) as described above. The data that the aperture value AV is O” is displayed on the display (D
S), the aperture display will become as shown in Fig. 3(D). The aperture display in condition 3 may be a value other than the aperture position being used, such as displaying "00" or 99, blinking the displayed aperture value, or not displaying the aperture value at all. Then, proceeding to step #67, the display data set as described above is transmitted from the microcomputer (μC) to the display unit (DS).

As a result, the display section (DS) displays the aperture value Av and the shutter speed value Tv, and blinks or lights up the "F" mark.

Further, in this embodiment, the data of the preview correction amount ΔPv is stored in the ROM of the lens, but the present invention is not limited to this, and a large amount of data of ΔPv may be stored in the camera body. The corresponding data may be selected depending on the lens type signal.

Further, in the above embodiment, it was not possible to operate the preview mechanism to narrow down the aperture when the AE block was applied, but a modification example that makes this possible will be described next. 1st
FIG. 2 is a flowchart showing a part of the modification, which is a modification of the flow in diagram m5 of the above embodiment.

The difference between the 70-chart in FIG. 12 and the flowchart shown in FIG. At step #19, the AE flock flag (
AELF) is set, the state of the preview mechanism/inch (SpV+) is determined by rubbing step #19 (rather than rubbing the stem #22 as shown in Figure Flf15).

Furthermore, in this modification, after controlling the preview in step #21, the reset flag (RESE
TF). This will be explained later.

FIG. 13 shows preview determination 70- (corresponding to 70- in FIG. 6 of the previous embodiment) of this modification. In this modification, first, when it is determined in step #27 that the narrowing down detection switch (Sl) V2) is "ON",
Proceed to step #101 and set the AE flock flag (AE
The state of the AE flock flag (A
If E L, F) have been reset, proceed to step #104 and set the reset flag (RESETF), then proceed to step #28, set the preview flag (PV F), and input the next DX code. Proceed to the flow. On the other hand, if the AE flock flag (AELF) is set in step #101, the process proceeds to step #102 and the reset flag (RESETF) is set.
Determine the status of. Here, this reset flag (RE
SETF) is used to set the AE lock flag (AEL
F) is used to reset the photometric value in the operating state of the preview mechanism. When the reset state of the reset 7 lag (RESETF) is determined in step 102, the process proceeds to step #103 and the AE block 7 lag (A
E L F ) and then step #10.
4, the reset flag (RESETF) is set and the process proceeds to step #28.

On the other hand, in step #102, the reset flag (RESET
When it is determined that F) is set, the preview mechanism is activated and the CIAEa check is performed, and the process proceeds to step 70- for inputting the next DX code. With this configuration, the preview mechanism can be activated during the AE clock.

The above describes the operation of the aperture-priority automatic shutter speed control mode or manual exposure control mode, but in the case of the shutter speed-priority automatic aperture control mode and the program automatic exposure control mode, the aperture value is determined by performing predetermined calculations, respectively. It is sufficient to calculate the aperture value and operate the preview mechanism or perform exposure calculation or exposure control based on the aperture value.

(Left below) Chuho! As described in detail above, the present invention provides a camera system having a preview mechanism that narrows down the aperture of a photographic lens attached to a camera body to a predetermined aperture value. 1 whether the preview means and the preview mechanism are activated;
! a lens information outputting means for outputting lens information regarding the photographing lens; a photometering means for metering the subject light transmitted through the photographing lens; and a calculation for calculating an appropriate shutter speed according to the photometry result of the photometry means. means, an AE lock means for storing photometry results at a time point corresponding to manual operation, a lens information storage means for storing lens information when the AE lock means is activated, and a determining means when the preview mechanism is in operation. The present invention is characterized by comprising a correction means for correcting the calculation result of the calculation means based on the lens information stored in the lens information storage means and the current lens information when it is determined that the lens information is present. By configuring the AE while the preview mechanism is operating.
Even if zooming is performed after flashing, exposure calculations can be corrected according to changes in aperture value due to zooming, so accurate exposure calculations can always be performed even while the preview mechanism is operating.

[Brief explanation of the drawing]

FIG. 1 is a top view showing a camera body according to an embodiment of the present invention.
2 is a front view of the same, FIG. 3 is a diagram showing the display mode of this embodiment, FIG. 4 is an electric circuit diagram thereof, FIG. 5 is a flowchart showing an outline of its operation, and FIGS. 6 to 11 are Flowchart showing details of each operation, FIG. 12 and f513
The figure is a flowchart showing a modification of the above embodiment, plS
FIG. 14 is a graph showing the relationship between the aperture value and the TTL photometry value. (P B ); Preview means, (PV F); Discrimination means, (LR); Lens information output means, (LM); Photometry means, (μC); Calculation means, AE lock means, lens information storage means, correction means. 'Is Figure 1 Army Figure 2 Figure 7 L--j

Claims (1)

[Claims] 1. A camera system having a preview mechanism that narrows down the aperture of a photographic lens attached to a camera body to a predetermined aperture value, comprising: a preview means that is manually operated to operate the preview mechanism; and a preview mechanism. a determination means for determining whether or not the camera is activated; a lens information output means for outputting lens information regarding the photographic lens; a photometry means for metering the subject light transmitted through the photographic lens; a calculation means for calculating an appropriate shutter speed according to the manual operation; an AE lock means for storing photometry results at the time of manual operation; and a lens information storage means for storing lens information when the AE lock means is activated. and correction means for correcting the calculation result of the calculation means based on the lens information stored in the lens information storage means and the current lens information when the preview mechanism is determined by the means to be in operation. A camera system having a preview mechanism characterized by: 2. A camera system having a preview mechanism according to claim 1, wherein the lens information output means includes information regarding the amount of change in aperture value with respect to change in focal length of the photographic lens.