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Adjustable
Cameras
Do not be shy of a conventional,
adjustable camera. There are only three primary controls: focus, shutter
speed and aperture, making the camera elegantly simple. By comparison,
it is not unusual for a modern automatic camera to come with a thick
manual and a myriad of buttons and viewfinder symbols to learn. Exposure
is handled by manual cameras with either a built in "manual
meter" or an external belt or pocket meter. My favorite outfit is a
35mm single lens reflex with three interchangeable lenses and a separate
hand-held meter. A separate electronic flash and an assortment of
filters and minor accessories (flash extension cord, cable release,
tripod, carrying satchel, etc.) round out the field equipment for
serious amateur photography.
Film
Format
Perhaps it may surprise you, but the eye
has a circular
field of view just like any camera lens. Very early cameras actually took circular
pictures taking advantage of the maximum lens image. For a
while, square pictures were popular, notably, the 2 1/4 x 2 1/4 roll
film cameras of the 1930's and later. The square format has its
advantages because it more closely approximates the way we see, but
rectangular formats like 35mm enjoy the esthetics of the rectangle, a design principle advanced by the Greeks. In reality, the
35mm frame which has a ratio of 1:1.5, just a little more square than
the true Golden Rectangle which has the ratio of 1:1.618 or about 5:8. Serious amateurs
used roll film until perhaps the 60's when 35mm gradually dominated the
scene. But even today, many professionals shoot roll film because
greater quality is achieved when making big blowups. By cropping, either
format can be printed as square or rectangular, to best suit the
subject.
Controls
of Adjustable Cameras
Because I have occasionally referred
to "stops" and other photographic terms, I will briefly
discuss nomenclature and some theory. A fast lens has a large aperture.
Aperture is described in terms of f/ stops aka f/ numbers. The range of f/ stops,
from largest to smallest, is f/1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32
and 64. Fast lenses have low f/ numbers such as f/1.4 or f/2. Each f/
number in the series allows half the light to pass through as the
previous number. In conjunction with f/ stops, the shutter controls
exposure. The common shutter speeds, from slowest to fastest, in seconds,
are 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, and 1/1000.
Note each speed in the series is twice as fast as the previous speed,
allowing half the light to pass through the lens. Sometimes you will see
other speeds, such as 1/100, 1/300, 1/400 etc., but the principle is the
same. High shutter speeds have smaller fractions. By combining aperture
and shutter speed, exposure is determined. the formula being E = I x T,
where E is exposure, I is intensity, and T is time. The f/ stops
determine intensity and the shutter speeds determine time. The film
package insert will give you basic exposures for several kinds of
lighting; i.e., for ASA (or ISO) 100 film, in sunlight, it is 1/125 @
f/11. In shade it is 1/125 @ f/4. Both shutter speeds and f/ numbers can
be adjusted to yield equivalent exposures. Here are a few examples: 1/60
@ f/16 is exactly the same exposure as 1/500 @ f/5.6. Use the first
setting for lots of depth of field and the second setting for stopping
action. No memory, reference to tables or calculations are used to go
from one setting to another. Just go stepwise, one shutter speed or f/
number at a time. As you advance the shutter faster by one step, open
the lens one stop. Then repeat until you get to the combination you
need. You can also go two, three, or four steps at a time with a little
practice. Depth of field refers to the range of acceptable sharp
focus, in terms of distance of the subject from the lens. It varies
according to the aperture and point of focus for a given focal length.
For example, with a 50mm lens, set to f/16, the maximum depth of
field is found at the hyperfocal distance, 14 feet, where everything is
in focus from 7 feet to infinity. The same lens is only good for a one
inch depth of field when set to f/4 and focused on an object 18
inches from the film plane. At larger apertures and closer distances, the depth of field is diminished drastically,
requiring careful focusing. But it is this characteristic which allows
the photographer to throw backgrounds out of focus. A good manual camera
has a button or lever on the lens called a depth of field preview
control, which allows you to see the actual image as it will be focused
onto the film emulsion. Other cameras rely on a depth of field scale
printed on the lens barrel. It tells you the closet and farthest objects
in focus for a given distance and f/ number. If you use an automatic
camera, you don't ever have to think about anything in this paragraph,
but you are shooting blind because you don't know what is in focus or
out and whether or not you are going to stop the action. You are also
likely to have no control over the flash. Automatics are primarily
designed for people who just need a quick, but compromised picture with
a minimum of equipment and knowledge.
Filters
for Color Films
To darken blue skies, reduce specular
reflections, and increase color saturation with color films, use a
polarizing filter in front of the lens. A single lens reflex viewing
system is best so the effect of the filter can be seen. Turn the filter
ring until the darkening effect is satisfactory. An exposure increase is
necessary because the filter traps a portion of the light. The amount of
exposure adjustment is variable from about 2.5 to 4.5 times (filter
factor 2.5 to 4.5). An automatic camera using TTL (thru-the-lens)
metering will make this adjustment for you without any thought.
Otherwise, estimate the adjustment at about 2 stops. When shooting color
transparency film, you will find the pale blue 82A filter useful for color
correction of the sun's excessively warm light late in the day or early
in the morning and the pale yellow 81B filter good to reduce the coolness of overcast
skies. These filters are effective also for negative films; anything you can
do to get a balanced image on film in the camera will save a lot of
headaches later in the darkroom or in front of a computer monitor. A
good general purpose filter to keep on the lens is the skylight filter,
which helps reduce the blueness of open shade shots as well as protect
the lens from dirt and damage. It has no effect in bright sunlight. Many
point and shoot cameras do not have any provision for attachment of
filters, thus further limiting them as serious picture takers.
Filters
for Black and White Films
If using conventional monochromatic
film, blue skies usually print white, obscuring clouds. To bring out the
clouds, affix a K2, medium yellow filter. The filter absorbs blue and
ultraviolet to darken the sky. the white clouds render as normal. Since
the filter absorbs light, an exposure adjustment is needed. Simply
double the exposure by opening the lens one stop, if a manual camera is
used. Other, particularly strongly colored filters have been used with B
& W, including orange and green filters.
Film
Selection and Exposure
Very little slide film is sold these
days. It just has too much overhead. Unless you intend to project
slides, you will probably find negative films yield much better
results. However, Kodachrome 64 is excellent for taking test shots
to calibrate your camera, meter and flash. Negative film is no good for
this purpose. A gray scale and color chart make good targets. Use
exposure bracketing. Bracketing means making an exposure at the
calculated value, then at 1/2 and 1 stop over and under. Select the best
slide and this becomes your calibrated exposure. Example: the best sun
lighted shop is 1/2 stop under. Reset the ASA dial of the exposure meter
to a higher speed equivalent to 50% faster film (ASA 64 to ASA 100). The
meter is now compensated for best results. Old mechanical equipment
frequently slows down, overexposing film. Fortunately, for negative
film, this is usually of no consequence. Ignore film box descriptions
that say 100 speed film is for daylight and 400 speed for cloudy days.
100 speed is a very good all around choice, if you have a fast lens.
High speed film tends to be expensive, grainy and severely limits the
use of large apertures to throw backgrounds out of focus, without
resorting to neutral density filters to "slow" down the film.
Fast films improve indoor flash range but do nothing outdoors for
boosting fill-in flash range. A good hand-held meter will really help
you out in difficult lighting situations. I recommend an incident light
meter, not the reflected light kind. The meters carried by motion
picture film makers
are incident light meters. Built-in camera meters are of the reflected
light meter design. A good digital meter will actually do both, incident
and reflected, plus measure flash light, useful primarily in the studio
to balance multiple flash and determine the effective power of bounce
flash.
Consult the owner's manual or a textbook as to the proper use of the
light meter; the time will be well spent.
Taking
Sharper Pictures
For hand-held exposures, use a
minimum shutter speed of 1/ focal length of lens in mm. Example, you
have a 180mm telephoto or zoom lens. Use 1/250 shutter speed. Otherwise
you risk camera shake, with a loss of detail on the film. Notice that
longer focal length lenses demand larger apertures also, which runs
contrary to inexpensive zoom lenses. That is why I prefer fixed length
lenses. A 28 mm high quality f/2.8 wide angle lens can be purchased on
the used market for about 35 dollars! Fixed focal length lenses also
have fewer glass elements and moving parts making for lighter and higher
contrast lenses. For the sharpest hand-held photos, brace you elbows
against your body, hold you breath momentarily and gently squeeze the
shutter release. Take a picture of the same scene with the camera
hand-held and then with a tripod. Compare the results for sharpness to
check your technique. A monopod or improvised brace such as a wall,
fence, or tree will allow much lower minimum shutter speeds, useful for
poor light shots. It is said that sharpness is really a psychological
term, determined by the more rigorous science of resolution and
contrast. Photography has a huge body of knowledge attached to it and it
is growing in this age of computers.
Electronic
Flash Indoors and Outdoors
Flash is calculated from a constant known as a guide number. The guide
number (GN) is supplied by the flash manufacturer and the specification
is usually given for a film speed of ASA 100. Say a particular guide
number is 80. The same flash would have a GN of 110 if 200 speed film is
used, and a GN of 160 for 400 speed film. To take an indoor direct flash
picture, set the shutter at the sync speed (on older cameras, usually
1/60) and simply divide GN by the camera-to-subject distance to
calculate the f/ number. Example: Using 100 speed film, 10 foot subject
distance, the aperture required is f/8. Substituting various distances
in the formula will show that doubling the distance requires two f/
stops more for the same exposure. From physics, light intensity falls
off inversely proportional to the square of the distance. The term f/
stop has been around for a long, long time; early photographers had a
good handle on math and science! For bounce flash, calculate subject
distance as the light path total from flash head to bounce surface to
subject. Do the f/ number math, then open the lens one extra stop to
compensate for the light loss at the bounce surface. A powerful flash is
needed for practical bounce flash. Outdoor fill-in flash can be
calculated exactly the same as indoor direct flash for a 2:1 lighting
ratio (full fill-in). Some flashes have a power control, used for
automatic flash exposure or attenuating power for close-up work or
fill-in using a constant aperture; consult the owner's manual. When
selecting a flashgun, look for GN ratings that are 10x multiple of f/
numbers, such as 80, 110, 160 and 220 to simplify calculations. The
higher numbers are desirable, but be sure it is powered by large
capacity rechargeable cells; i.e., size C or D, not AA or AAA's. To
avoid "red eye", avoid built-in flash for indoor use and
instead, use an attached flash on a camera bracket or use off-camera
flash. Slave flash is useful to achieve balanced lighting indoors. Many
pros dispense with flash altogether for portraits and commercial work
and instead use photofloods with which the photographer can adjust
visually for best results in terms of light, shadow and modeling.
Filing
System for Negatives, Slides, and Digital Images
I have developed a versatile
computer-file indexing system of infinite capacity for assigned a unique
designator for each and every image you create. These numbers can be
cross-referenced, if desired with a text-based data base, which can
provide text descriptors to aid in locating images. The important thing
is to be able organize and retrieve images expediently at a later date.
Letter code: y=year,
m=month, d=day, r=roll number, f=frame number, P=print, S=screen, .BMP=
bit map file, .jpg=jpeg file
Number code:
5x7=5"x7" nominal, 300=300 dpi (dots/pixels per inch), 96=96
dpi, 72=72 dpi
Infinitely indexed
image file numbering system: yymmdd_rr_ff_P5x7, yymmdd_rr_ff_S72,
yymmdd_rr_ff_S96
Example:
010119_02_17_S96.jpeg describes a jpeg compressed, 96 pixel/in., frame
#17 of roll #2, taken on Jan 19, 2001
Note: The suffix added
following ff_ can be altered to suit the purpose. If larger files are
stored, then P8x10 can used to describe the end application, an 8 x 10
print. The suffix .jpeg, .BMP, etc. can be omitted as the Explorer
detail view provides file type information. An additional word or two
suffix can be added to provide some description of the image. Right
click on a picture in this web and choose properties to view the file name; most
are named with the infinitely indexed image file numbering system.
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History
of Megapixels
Four megapixel cameras now entering
the marketplace are the epitome of digital amateur photography. But let
us not forget that amateurs, using silver halide roll film, were
routinely enjoying the equivalent of 45 megapixels half a century ago.
In some respects amateur photography has been in a state of devolution
for many years. I have seen an 8 x 10 Ektachrome transparency taken by a
view camera and it is something to behold; it is akin to looking through
a window at the real world. Its size, color fidelity, and contrast is
matchless. Such superb quality should be expected for it contains perhaps the equivalent
of 400 plus megapixels. Even old roll film negatives taken with
precision cameras of yesteryear can produce needle-sharp contact prints
unsurpassed by anything in the 35mm world today. Such prints, including
black and white ones, literally come to life. Nothing beats sharpness
except more sharpness. So here we are today, firmly enticed with 35mm.
Very few of us use larger format cameras because of the astronomical
expense associated with them. No one now expects digital to compete with
anything other than 35mm so 35mm becomes the benchmark with which each
new generation of digital is compared. Theoretically, 8 megapixels is
equal to 35mm.
Cameras
vs. Cameras
So, just how do 35mm film cameras
compare to digital cameras? Well, first of all, you need to consider the
camera function separate from the electronics. A camera, whether or not
film or digital, must first of all be a decent camera optically and
mechanically. A good benchmark is to reexamine good, medium priced SLR
(single lens reflex) cameras of the near past, the 1960's and '70's.
They were fitted with good, fast lenses coupled with a really good
optical thru-the-lens viewing system. Large and bright, the viewfinders
showed exactly what you would get on the film. Focus was on a
combination ground glass screen with a split-image rangefinder in the
center. There was a wide range of shutter speeds available. There was
provision for external flash sync, depth of field preview, depth of
field scale, cable release, and a tripod socket. The camera itself was
made from metal, glass, and durable plastics. There was the feel of
quality in the photographer's hands, for these cameras were the
instruments with which creative work could be accomplished without
limitations by equipment deficiencies. At this point in time, only a few
high end model digital cameras come close to the equipment just
described, with the popular priced models thoroughly incapable of
producing many of the images contained in this web. Think of an ideal
digital camera as a regular high quality camera to which has been added
the CCD chip and its associated electronics to digitize the image, the
image generated by the essentially conventional camera body and optics.
Currently the four megapixel camera achieving these qualities retails
for about $2000, in fine camera stores. Expect prices to come down
somewhat, but a truly fine camera has always and will continue to be
expensive, at least when purchased new.
Resolution
vs. Resolution and Other Problems
It has been stated by authorities
that full-frame 35mm film can carry a maximum of about 8 megapixels in
its emulsion. That would tend to make one believe that digital cameras
have a way to go yet to catch up with conventional 35mm. But there are
some other factors to consider. While 8 megapixels are theoretically
possible to extract in a contact print, 35mm is never used that way. The
negatives are enlarged and printed or scanned into computers either via
a flat bed scanner for prints or a film scanner for negatives and
slides. All these processes degrade the resolution and do so
significantly. My guesstimate is that the loss factor ranges from 10% to
90%. You can see for yourself. Just scan in a print, manipulate it, and
resize it. The image will get very soft; this represents a substantial
loss of resolution. That is why photo applications always have a
"sharpen" option to artificially restore lost detail. Using
darkroom techniques, there is a loss, though much less from projection
of film through an enlarger. Unlike computers, there is no way to
sharpen darkroom images. So, the bottom line is that megapixel cameras
may have already equaled 35mm. I have seen an 8 x 10 print made on a
high-end photo printer and it looked really good. I would have to see a
few more, especially of test targets and a variety of everyday subjects,
including people's faces to be sure. In particular, I would want to know
if the background noise problem of "artifacts" has been
eliminated. I suspect it has. Note that 35mm film also has an
"artifact" problem: dust and scratches, not to mention actual
particles embedded in the film at second-rate processing facilities.
There is the memory problem. Multi megapixel images take up very large
files, possibly up to 12 MB. Therefore on-camera mass storage quickly
becomes a problem. There are several solutions employed by the
manufacturers but they breakdown into two groups: solid state storage
and disc storage. Solid state memory modules are either limited in
capacity, too expensive or both. Floppies were originally used but now
hold too little for even one top quality image. Optical disc storage
seems an viable approach, but adds considerable bulk, weight, and power
consumption. It has the advantage of unlimited media availability and
the disadvantage that it is an expendable, unlike solid state
memory. Further development needs to be made in this area. When
you travel, you need to either carry plenty of media or be able to buy
it. Film is available everywhere at reasonable cost and is no problem.
Solid state memory is so expensive that you will need to periodically
download and reuse it. The optical discs used in cameras are of a
special miniaturized type and you will have to carry plenty with you if
you leave major metropolitan areas or travel to regions where such
supplies are not yet sold. Finally, before the world forsakes film
altogether and goes en masse to digital, there must be commercial
processing widely available at prices competitive with today's film
processing. We need to be able to take our memory chip, optical disc, or
other mass storage device (laptop, portable hard drive, etc.) to the
local film lab and have on-premises printing of the images on archival
paper utilizing archival inks.
What
Now? What Next?
The use of a hybrid photographic
process is still the norm and was the method used to prepare this web. A
film camera was used to generate the images which were then scanned into
the computer. Mostly a film scanner was used. After processing in a
photo application, the files where then incorporated into the web. Each
image was stored at varying resolutions: 300 dpi @ 5 x 7 inch nominal
for printing, 96 dpi @ 512 x 768 nominal for large screen monitors (1280
x 1024), and 72 dpi @ 252 x 378 nominal for small screen monitors (640 x
480). There is no doubt that the best digital cameras today could have
done as well as the conventional camera I used for this project, and
done it faster and easier. It is a chore to scan in prints, negatives,
and slides. Downloading images from a digital camera is a snap. Manley
will surely go digital for his picture taking requirements. We
old-timers will hang on to our fine film cameras for a while.
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