 |
Description  |
|
|
The present invention relates generally to the recording of exposure data
in association with photographs, and more specifically to recording data
describing intentional variations from a nominal exposure for providing
information to an observer.
BACKGROUND OF THE INVENTION
It is known in the art to record aperture and shutter speed information in
relation to photographic pictures. U.S. Pat. Nos. 3,843,956 and 4,001,846
to Kauneckas show electronic apparatus for recording such information
directly on a film, while U.S. Pat. Nos. 3,995,289 to Shono and 3,736,849
to Thompson show opto-mechanical apparatus for doing the same. Further, at
least one camera manufacturer makes available a data-back for a camera,
including an alpha-numeric keyboard, which permits exposure data in
combination with operator-selected messages to be recorded in relation to
an exposed film.
A disadvantage of prior art cameras is that, in instances wherein a user
intentionally varies a camera exposure from a suggested nominal exposure,
no accommodation is made for recording the varied exposure. Such instances
arise, for example, in cameras of the type providing both a recommended
nominal exposure, and the ability to deviate from the nominal exposure for
such purposes as exposure bracketing. Since no accommodation is made for
recording the varied exposure, this information is not available to the
subsequent observer of the finished photographic prints or transparencies.
Thus, in situations where the user has intentionally varied an exposure,
he is typically left guessing what exposure was used for a subsequently
finished print or transparency.
SUMMARY OF THE INVENTION
Accordingly, a principle object of the present invention is to provide
information indicating an intentional variation from a nominal exposure
for use during the evaluation of photographic prints or transparencies.
Another object of the present invention is to provide a photographic camera
which automatically records exposure data indicating an intentional
variation from a nominal exposure.
A further object of the present invention is to provide a system for
processing and mounting a transparency which indicates on the mounted
transparency if the exposure selected for the transparency was
intentionally varied from a nominal exposure.
Yet another object of the present invention is to provide a photographic
printing system for printing a photographic negative onto a photosensitive
paper which indicates on the photographic print if the exposure selected
for the negative was intentionally varied from a nominal exposure.
In accordance with a first embodiment of the present invention, a new and
improved method of operating a photographic camera to provide exposure
information in association with a latent image picture frame comprises the
steps of:
automatically providing a nominal exposure for the picture frame;
providing an operator-selected exposure for the picture frame which differs
from the nominal exposure by a known under- or over-exposure;
exposing the picture frame in accordance with the operator-selected
exposure; and
recording data in association with the picture frame which indicates the
difference between the nominal and operator-selected exposures.
In another embodiment of the present invention, a new and improved method
of providing exposure-related data in association with a mounted
photographic transparency comprises the steps of:
reading data associated with the photographic transparency, the data
indicating if the transparency was purposefully exposed at an
operator-selected exposure different from an automatically supplied
nominal exposure; and
recording data in association with the mounted photographic transparency
indicating to an observer the under- or over-exposure of the transparency.
In yet another embodiment of the present invention, a new and improved
method of operating a photographic printing system to print a photographic
negative onto a photosensitive paper, whereby to produce a subsequently
developed photographic print, comprises the steps of:
reading data associated with the negative, the data indicating if the
negative was purposely exposed at an operator-selected exposure different
from an automatically supplied nominal exposure; and
marking the photographic print to indicate to an observer the under- or
over-exposure of the negative.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims defining the features of the
invention that are regarded as novel, it is believed that the invention,
together with further objects thereof, will be better understood from a
consideration of the following description in conjunction with the drawing
Figures, in which:
FIG. 1 is a block diagram of a photographic camera constructed in
accordance with the present invention;
FIG. 2 is a flow chart illustrating the operation of the camera of FIG. 1;
FIG. 3 is a block diagram of a photographic slide mounter constructed in
accordance with the present invention; and
FIG. 4 is a block diagram of a photographic printing system constructed in
accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, FIG. 1 shows a photographic camera 10
including a transport mechanism 12 for supporting and advancing a
conventional silver halide filmstrip 14. A lens 16, aperture mechanism 20,
and shutter mechanism 22 are positioned to control the exposure of picture
frames onto filmstrip 14. As used herein, a "picture frame" comprises an
undeveloped, latent image scene. A controller 18, for example a
microprocessor, is connected to the aperture and shutter mechanisms 20,
22, and to film transport mechanism 12. An automatic exposure control
photosensor 24 and a shutter release button 26 are both connected to
controller 18, operation of the shutter release button causing the
controller to set aperture 20 and actuate shutter 22. The above-described
components represent conventional features and will not be discussed in
detail herein.
In accordance with the present invention, an automatic exposure
compensation control mechanism 28 is connected to controller 18. A
recording device 30 is likewise connected to controller 18 and positioned
adjacent filmstrip 14 for marking the filmstrip. A manual exposure
compensation control mechanism 32 includes controls such as thumbwheels
(not shown) mounted on the outside of camera 10, the operation of which
varies the adjustment of aperture 20 and shutter 22.
Automatic exposure compensation control mechanism 28 comprises apparatus
for automatically "bracketing" a nominal exposure selected by controller
18 responsive to the light sensed by sensor 24. Mechanism 28 functions to
automatically provide a selected number of exposures in addition to the
nominal exposure: i.e. one under- and one over-exposure. The amount of
under- and over-exposure can be pre-programmed, or controlled by a
photographer. Alternatively, exposure compensation control mechanism 28
can be operated to provide a predetermined under- or over-exposure for
selected frames, without the above-described bracketing. Such operation is
desirable, for example, to provide purposeful over-exposure to compensate
for back-lit scenes.
Recording device 30 comprises apparatus for recording data onto filmstrip
14 in, for example, a latent image, mechanical, or magnetic format. If
latent image recording is desired, recording device 30 can comprise a
light pipe or light emitting diode (LED). If mechanical recording is
desired, device 30 can comprise a mechanical punch. Similarly, if part of
filmstrip 14 is adapted for magnetic recording, recording device 30 can
comprise a magnetic write head.
Manual compensation control mechansim 32 comprises apparatus for permitting
an operator (not shown) to manually override the nominal exposure
automatically supplied by controller 18, and to manually adjust aperture
20 and/or shutter 22 to provide a user-selected exposure. Manual
compensation control mechanism 32 can comprise, for example, user-operable
thumbwheels appropriately connected to aperture and shutter mechanisms 20,
22.
In operation, described with respect to the flow chart of FIG. 2, upon the
activation of shutter release button 26 by a user, controller 18 functions
to automatically provide a nominal exposure for filmstrip 14. This nominal
exposure is selected responsive to the ambient light sensed by sensor 24,
and the selective activation of a flash (not shown). The providing of such
pre-programmed or calculated nominal exposures is well known to those
skilled in the art, and will not be discussed further herein.
Next, controller 18 senses the input of automatic exposure compensation
control 28 and manual exposure compensation control 32 to determine if the
user has manipulated either control to select an exposure other than the
automatically provided nominal exposure. If no exposure compensation is
provided, the filmstrip 14 is exposed with the nominal exposure. Recording
device 30 is then activated to record on filmstrip 14 data indicating that
the nominal exposure was used. Alternatively, the absence of data could be
used to indicate the nominal exposure was used.
If controller 18 determines that exposure compensation has been provided,
either through automatic controller 28 or manual controller 32, aperture
20 and shutter 22 are set to provide the desired, user-selected exposure
to filmstrip 14. Controller 18 calculates/determines the difference
between the automatically provided nominal exposure and the user-selected
exposure. Such a difference is typically expressed in "stops", for example
one change in f-stop, or a halving (or doubling) of shutter speed. The
user-selected exposure is made on filmstrip 14, and controller 18
activates recording device 30 to record data indicating the difference
between the nominal and user-selected exposures on the filmstrip. If
automatic exposure bracketing is selected as described above, the
compensated exposure and concomitant data recording will, of course, be
performed for each of the bracketing exposures.
The present invention has particular application with respect to the
analysis of photographic transparencies. As is known in the art,
transparency film is particularly sensitive to deviations from the nominal
exposure. Further, because no printing process is used wherein deviations
in exposure can be corrected, any exposure compensation provided by a
camera will be very apparent upon viewing the transparencies.
Referring now to FIG. 3, a transparency processing system 40 constructed in
accordance with the present invention includes conventional processing and
mounting stations, 42, 44, respectively. A transparency film 46 is removed
from a light tight cartridge 48, and moved seriatim through processor 42
and mounter 44.
In accordance with the present invention, a sensor 50 is provided upstream
(i.e. before cutting and mounting) of mounter 44. A data memory circuit 52
is provided intermediate sensor 50 and transparency mounter 44. A
transparency mount marker, for example an ink marker, is provided in
mounter 44.
In operation, sensor 50 senses the exposure compensation data recorded with
each image frame on filmstrip 46, and transmits this data to mounter 44
via memory 52. Data memory 52 insures that the correct data is
synchronized with its corresponding image frame as the image frames are
cut and mounted by mounter 44. Transparency mount marker 54 is actuated,
responsive to the exposure data, to mark the data in human-readable format
on the transparency mount. Thus, a viewer can view the mounted and marked
transparencies indicated at 56, and determine if an exposure compensation
was provided when the image was exposed. Transparency mount marker 54 can
optionally be actuated to mark the data in a machine-readable format on
the transparency mount, thus accommodating automated display of the
exposure compensation information.
The invention has further application in a photographic printer. More
specifically, the data recorded with each exposure can be used to mark the
subsequently made print, thus informing the photographer of any
intentional variation in exposure.
Referring now to FIG. 4, a photographic printing system 60 is shown
constructed in accordance with the present invention. System 60 includes a
printer 62 for printing consecutive, developed negative frames on a
filmstrip 64 onto photographic paper 66. A controller 68 such as a central
processing unit (CPU) is provided for controlling printer 62, including
providing/calculating a nominal printing exposure for printing each
negative frame.
In accordance with the present invention, a sensor 70 is positioned
adjacent filmstrip 64 and upstream of printer 62 for sensing exposure data
of the type described herein above. A data memory 72 is provided
intermediate sensor 70 and printer 62. Alternatively, sensor 70 can be
positioned at the print station in printer 62, negating the need for
memory 72. A marker 74, for example an ink printer, is provided in printer
62 for marking the back (i.e. non-emulsion) side of photographic paper 66
in accordance with the sensed exposure data.
In operation, sensor 70 functions to sense the exposure data recorded with
each negative frame on filmstrip 64. The sensed exposure data is
transmitted to printer 62 via memory 72, the memory insuring the
synchronizing of the data with its' corresponding negative frame.
Photographic print marker 74 is actuated, responsive to the exposure data,
to mark the data in human-readable format on the back of the print. Thus,
a viewer/photographer can view the subsequently developed, marked prints
and determine if an exposure compensation was provided when the image was
exposed. Photographic print marker 74 can optionally be actuated to expose
the data directly onto the emulsion side of the photographic print, for
example along an edge.
There is thus provided a method and apparatus for associating data
indicating user-provided exposure compensations with each latent image
exposed in a camera. Further provided are methods and apparatus for using
this exposure compensation data to advantage in viewing subsequently
produced photographic prints and transparencies. More specifically, a
transparency processing and mounting system is provided for marking the
exposure data directly on the transparency mount, permitting a viewer to
appreciate the results of his exposure selection. A photographic printing
system is likewise provided for marking the exposure data on prints. There
are thus provided convenient, automatic systems for marking prints or
transparencies so as to later remind the user of the exposure compensation
provided.
While preferred embodiments of the invention have been illustrated and
described, it will be clear that the invention is not so limited. Numerous
modifications, changes, variations, substitutions and equivalents will
occur to those skilled in the art without departing from the spitit and
scope of the present invention.
* * * * *
|
|
 |
|
 |
Description |
|
