Seneca Camera Mtg. Company Product booklet

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The Amuteur
   Photogrupher's
      Munuul





     A Complete Compendium .fo, the
        Beginner and Adeanced Ama.teur

           Edited and Published by the
S enecu C umer u MfS  . C omp aruy
              Factories and Offices
       ROCHESTER, N. Y., {J. S. A.

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TIIE AMATEUR PHOTIOGRAPHER'S MANUAL
THE NATURE OF PHOTOGRAPIIY.
LTHOUGH the process of picture mak-
ing known as photography has been sur-
rounded with a great deal of secrecy, it is nevertheless wonderfully simple. By
the camera an impression is made upon
a sensitized surface, either a film or a
plate. Through the action of chemicals
this impression becomes permanent and
visibie. The result is called the negative
since the light parts as the eye sees them are daik and
vice-versa. By_ letting light shine through the negative
and upon another sensitized surface, which usuallv is
pap9r, another_impression is formed'which, actecl upott
by chemicals, shows the light and dark parts as the eye
sees them. This result is the picture.
THE CAMERA
The camera begin_ning is the of photography. "closerWith- -areo_ut photographs jt what and sometimes to
the. heart-snapshots-would be impossible. Although
it has also been the victirn of myslery,-are it is wonder.-fully simple. Its essential parts f6ur in number;
a lens to throw an image of the subject upon & sensi..
tized-surfacel a sensitized surface to ieceiv6 the image;
a bel-lows to.protect the sensitized surface from the lighf
which would otherwise block out the image formecl"bythe lens and a shutter to keep light Irom passingthrough the lens and to measure the- proper e*r,o-iore.All other parts of the camera are mefely'conveiiie.rcesfor operation.
,-,There,are.many styJes of cameras upon the market.'l'he inclination of the American buyer has wisely
been to select one light in weight and simple i" op"r"_tion. Filnr either in roll oi pack form- atiowd tfreoperator to carry so manv more exposures that forar'ateur use it has largely displaced the use of plates.The simplest of all is thir bof camera like the Tcout.
IhgS" are very simple to operate and give good pic-turesto the in_experienced user in most case5. H6wev6r, their
r?ng.e of use is somewhat restricted on account of tneelimination of various adjustments and are somewhat

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fHE AMATEUR PIIOT.OGRAPIIER'S MANUAL
inconvenient to carry about. The folding model with
round ends has attained gre-a! popularity .for theseieasons.-attractiveAn inexpensive model as the Folding Scoutis to those who desire something more than
th" b;i siyle. The higher priced^senecamodels similar to the are- equipped Chief the attd'iioil-Fit-"-t""t"tS"tr""u being besides quality highest of the*itft finer for adjustments and allowing finishedeleganily" com- shorvn for very recently preference Thei"sittt..nacl instrumeirts has been responsible for cameras of
ihe type of the Vest Pocket Seneca and thejunioi. These smaller cameras also offer the choiceSenecaof
hiEh Erade lenses of the Anastigmat type which pro- -"ugatives especially suitable for enlat'ge-me-nts'A"?"
.A*dvattced amateuri often choose weII equi-pped plate;il;;-;"ints Iike the Senecas No. 8 and No' 9 in seeing ;;.Gi'-io se"n"" the advantages for fine work inthe picture before it is taken.
LENSES.
A careful amateur will give first consideration to his
lens. Four general types are in use: Meniscus Achro-
matic, Rapid- Rectiline-ar, Symmetrical Convertible and
Anastigmat.
. TIIE MENISCUS ACHROMATIC LENS.
A Meniscus Achromatic is the simplest of lenses. Early lens makers found that a single piece of glass would scatter the colors just like the prism that a teacher hangs in the sunshine in the schoolroom. A
film or plate is affected by the rays at' the violet end of the spectrum, i. e., rainbow, while the eye sces only the red rays. To focus these upon the same point, two kflds. of glass of different dis- persive, i. e., scatterilg power were combined. Achromatic means literally to get away from color.
The new lens was found to be moonshaped, i. e., menis- 'i'he cus. The better lenses are of course used upun
more expensive cameras and are capable-o_f finet' results
than the less expensive. However, the difference in the
results each one will produce depends more upon the
range of conditions un-der which each one may.be used
thai upon the excellence of the pictures themselves. It
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THE AMATEUR PHOTOGRAPHER'S MANUAL
is a simple matter to make a lens for a limited use and
for a small camera and still to be capable of producing
a good picture. But the difficulties of a lens maker
multiply when he attempts a lens suitable for a wide
range of conditions and a large camera. The little lens
in a Scout Camera will make good pictures within its
Iimitations. Since the two pieces of glass in a Meniscus
Achromatic Lens are apparently one, it is commonly
called a "single lens." It is always used behind the
shutter.
DEFINITION.
As eflorts were made to produce lenses with ferver
limitations, the Meniscus Achromatic proved to be less
efficient in throwing the rays of light upon the plateor film. While we ordinarily speak of rays of light,
we really men penciis of light for they must have a
diameter. These.pencils of light do not fall singly upon
the film or nlate but overlan and make what are called
"circles of cbnfusion." If these circles of confusion are
not greater in diameter than 7/200 of an inch, the
result is not noticeable to the naked eye and is accord-
ingly a clear picture. The larger lenses which were
first made showed circles of confusion greater thanl/700 of an inch and consequently produced blurredpictures. In lens terms, they did not gtve good
"definition."
COVERING POWER.
Another difficulty which the early lens makers foundwith the larger Meniscus Achromatic lens theyattempted was that the circles of confusion were of
different diameter at the edges then they were in the
center of the picture. In plain words, the outside por-
tions of the picture were llable to be blurred while-the
center was perfectly clear. Or if the lens were focused
so that the outside portions were perfectly clear, the
center in turn was blurred. In lens terms, they did not
give good "covering power."
SPEED.
A Meniscus Achromatic Lens was also found to give
clea-r pictures only with a small opening. If it wereused with one opening so large that- light passed
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\ THE AMATEUR PHOTOGRAPHER'S MANUAL
through a considerable area of the lens on its way to
the fi.lm or plate, the definition and covering power were poor. Ttre opening at which good pictur-es could
be obt-ained was so-small that a snapshot could be made
only when the sun was shining dire-ctly. upon the object in the middle of the day. As a result, it was necessary
to have a lens of greater "speed." With ordinary hand cameras it is customary to use a lens which is in focus at a distance from the plate
equal or somewhat greater than the diagonal of the film
or plate with which it is to be used. In lens terms this dis-
tance, which is for most lenses very close to the distance
ofthe diaphragm of the lens from the sensitized surface,
is called the "fbcal length." Focal length and the diam- eter of the lens opening measure the speed of a lens.
With most lenses the diameter of the lens opening is very
close to that of the diaphragm opening. Speed is rated
bv dividinE the diameler of the lens opening by the f6cal lengtE, which ratio is denoted by the letter f or F.
A Meniscus Achromatic Lens except for the smallest
size used by amateurs today cannot be used at a greater
diameter than l/16 of the focal length, or in lens terms, at a greater speed than f 16. If these first lens makers could get a lens capable of taking a good s-n-apshot
with an opening of twice the diameter, it would -mean that four limes as much light would pass through the
lens in the same fraction of a second, since the area of
a circle varies accordinE to the square of its diameter.
Consequently the light fo make a4 impression ^upon the sensitiZed srirface would have to be only one-fourth as
as i. e., one-fourth opening the strong "Thisas with greater is f 8.^Iarge,A speed fou-r times speed f 16. twice as great as f 16 but one-half that of f 16 was
found to be f 11.3. Under a lens will be found a series of figures including all or the larg_er figures. o_f this
serieS: f 4.5,6.3, 8, 11.3, 16, 22,32. When the indicator
below the lens points to one of these, t-he-area-of the,
lens opening, and consequently -the spee{ gf the lens, is either-one-lialf or twice that when the indicator points
to the one beside it. (f 6.3 is 617o faster than f 8; f 4.5
is 3.2 faster than f.8.)
After this f system of marking had been in use for several years it was found that beginners were apt to

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THE AI{ATEUR PHOTOGRAPHER'S MANUAL
consider that these figures _expressed the relative light openings. Acco_rdingly a Uniform System (U. S.) #as - devised which allowed the beginner t6 calcurate ieiative exposures easily. Under all except the hisher Erade
lens.es,- these_ figures appear: 4, 8,-76, gZ, 64, 129.- The
equivalent U. S. opening is placed under eich of the f series:
t 4.5 6.3 8 11.3 16 22 32 45 u. s. 1.3 2.5 4 8 16 32 64 L28
No matter what the large_st opening of the lens may
be, its speed changes when the ifrdicat-or below is moved pn5! is ahvays. shown by the number at which the rn0lcator ls porntrng.
THE RAPID RECTILINEAR LENS-DISTORTION.
In order to get a lens whose definition and covering
powe.r at a gry:gter speed than f 16,'Lens,the usual larsest opening of a Meniscus Achromatic lens maEers
placed a combination both before and behind the ihut_ter. It was named Rapid Rectilinear. It was twice as fast.as any other lens at that time. It also straight lines as such. This characteristic of""pr"r"rrtea'a lens of
not,nou .represenungrepresenting strai-ghtstrarght _lineshnes asas suchsuch isis knownknown asas distortion fou.nd _only in th_e images flrrown by ll/f andl -1,-, is ^-^:^^---Meniscus Achromatic Lenses. Distortion is easilyll<nlained on account of its action in the human eye. If a line were drawn along the side of a wall, a slight
curvature downrvard would be noticed more quiclily
than a slight curvature upward. The hnman pvtr eannot
g.asily distinguish between a straight
line and one curving slightly upward
Some Meniscus Achromatic Lenser
act exactly the same and would
make crossed lines appear.
The Meniscus Achromatic Lenses
upo4 cameras like the Scout are
adjusted so that objects are dis.
torted exactly the opposite. Crossed
lines would now appear.
Since the double lens eliminated distortionn it wasrightly termed Rectilinear, i. e., straight lines..
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THE AI\,IATEUR PHOTOGRAPHDR'S MANUAL
TIIE SYMMETRICAL CONVERTIBLE LENS.
Later use, however, proved that the Rapid Rectilinear
Lens did not give satisfactory definition and coverng
power at a greater speed than f 11.3. It was not yet
possible to take a snapshot on a cloudy day. - By -g{ngthree pieces of glass in each combination and a differ-
ent ar-rangement, a lens was made which gave satis-factory definition and covering power at a.-fFeed of
f 8. Shapshots in light shade were now possible. Thislens was*called Symmetrical Convertible, because with
a lens of this speed and quality photographic- tradevery often demands the additional qualitics of syrl-
*eity and convertibility. These two qualjties. go handin hind. Symmetry or the propgrty- of being-.-sYT-metrical means that the two combinations are alike rnthe same way as the right and left hands. A lens is
convertible *"hose sinEle-combinations can also be used
separately. Thus a pictulg may be taken with the trvo
coinbinations togetheir, with thd rear combination alone
and with the fr-ont combination alone. The advantage
of "th*"u-Ienses-in-one" is only when each obje-ctive has, diff"""t t focal length. A lens for a 5 x-7 plat" poyttu"e a focal length ;f 8 in.; its rear combination alone
14 in. and its fr6nt combination alone 18 in'
ANGLE OF VIEW
All ordinary lenses include approximately the sameobiects at a Eiven distance. In lens terms, their "angle
of" view" is the same. However, Ienses with greater
focal lengths show the objects co-rrespondingly.larger.
If a small plate were used upon I l4rg-e.camera rn,placeo? ih" regilar plate, the- individual objects -would stillbe of thd- same size, although the angle- of vie-rv was -of using a lens of greatsmaller. This is thi: effect
focal length upon a small camera.
THE ANASTIGMAT LENS. ' The advantage of having a fast lens capable of taking
a picture of &ceptional clearness has recently beenrecbgnized by the camera buyer. The Symmetrical
Convertible L-ens was found to be incapable of perform-ing the unusual demands placed upon it. A still better
tyFe, the Anastigmat, was invented. With its production
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TIIE AMATEUR PHOTOGRAPHDR'S MANUAL

isat comparatively increased speeds, i. e.' t 7.5, which7TYz%-faster than Symmetrical Convertible lens, it is
now becoming more and more popular. Astigmatism
is the inabilify of a lens to represent both horizontaland vertical lines with equal sharpness. If flne cross
lines of equal weight are phot-ographed, -the horizontallines will seem heavier than the vertical or vrce-versalvhen astigmatism is present. Although an-astigmat o-ne quality o-nly this(anti-astig-matism) implies 9I " have other usually ana-stigmat' lenses alsot'ens,
qualities.
In the discussion of Meniscus Achromatic Lenses,covering powerwas mentioned as the ability of a
lens to give good definition in the corners and in thecenter oT ttre film or plate at the same time. With
an Anastigmat Lens thit quality is evid-ent to the high-
est degree, either when used at a small or la-rgg gPen-
ing. Without becoming inv-olved in lens technicalitiesit-is enough to say that almost any Iens at a small
opening will take a picture as good as the best. Speed,
hbwever, is sacrifiCed. The Anastigmat Lenses of
nearly all manufactures are guaranteed to take picturesas good as the best at the largest opening, or in lens
terms at the greatest working aperture.-all Rememberin this connecti6n that speed is the important quality
of a lens for without speed the selection of subjects to
be "snapped" is greatly reduced.
DEPTII OF FOCUS.
It is necessary to focus a lens used at a high speectmore accurately than when used at a low speed. Take
for example the eye. It seems to change its focus
when the gaze is suddenlv changed from a nearby to adistant object. That's what happens to a lens when it
is focused. Without going to deeply into the laws of
optics, it is enough to say that a lens has a certainranEe before it in which it "sees" objects clearly. This
range is clearly defined and is called "depth of focus."
A lens at a high speed has a comparatively small depth
of focus and must accordingly be focused more accur-
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THE AMATEUR PHOT.OGRAPHAR'S MANUAL
To the student of lenses, it will be interesting toknow what other factors, if any, change this depth of
focus. There are twol the focal length of the lens and
distance the object is from the camera. The lens of
greater focal length at the same speed and distance
has the smaller depth of focus; the lens focused at a
shorter distance but at the same speed and of the same
focal length has the smaller depth of focus. Depth of
focus, then, depends upon
Speed
focal length
distance.
Microscopic definition is also present when Anastig-
mat Lenses are used at the greatest working aperture.
While inexpensive lenses take pictures apparently as
sharp, in most cases their definition does not last when
enlarged to considerable sizes. This quality is becom-
ing. more and more important with the increasing popu-
laritv of small compact cameras and subsequent en-
largement of the pictures to desired sizes. Accordingly
any Anastigmat Lens upon Seneca Cameras from fh-e
f:7.5 to the most expensive will not only do bettereverything than any other lens will do but also do
things the other lenses cannot do. The cost of a camerais not the large expense in a few years of picturetaking. Since a good lens costs but little more than
those of the cheaper grades, a purchaser will do wellto ask himself if he cannot successfully use one. An
owner should inquire at what expense he can equip his
camera with a lens capable of this better work-.
THE SHUTTER
That row of numbers above the lens indicates approx-
imately the fractional parts of a second during-wtrictr
the shutter remains open and allows light to passthrough the lens to the film or plate. f and B- areused for time exposure; the shutter at T remains open
after the first pressure until a second pressure closes itand at B only as long as the first pressure is continued.
Exposures at 7/25 and less may be made while the
c&mera is held in the hand and are accordingly called
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THE AMATEUR PHOTOGRAPITDR'S MANUAL
"snapshots." At I/25, take a man walking slowly; at50, "snap" children at play; at L/100, catch the speed-ing automobile at a distance and at L/200 get the diver
midway to the water. At these speeds it is difficult to
take the swiftly moving objects broadside without a
blur. Get them rather at an angle of forty-five degrees.
For photography of life in rapid motion, as the racing
automobile, the speeding express or the flight of the golf
ball, it is necessary to have a Focal Plane Shutter
which allows exposures as short as 1,21000 second. For
exposures longer than I/25 second, tbe camera should
be upon a tripod or some firm support. It should not be
held, in the kand,.
Shutter speeds have no relation to the speed of the
lens. A lens at f:11.3 has the same speed whether the
shutter is used at T or 1,2100 second. However, in
making an exposure, it is necessary to consider thespeed of both the lens and shutter. The lens speed
indicates how much light in a given time shall fall upon
the iilm or plate, the shutter speed how long that given
time shall be. All the popular brands of film or plates
as Vulcan Film and Vulcan Plates require about somuch light to fall upon them. If too much the negativeis over exposed; if too little under exposed. First, set
the shutter at the slowest speed at which it will notshow motion in the picture, then use the lens speed
recommended later under exposure. This allows the
smallest possible working aperture for the lens. Bylooking back to the discussion of lenses on page 5.you will see why it is always desirable to use a slow
lens speed.
THE SENSITIZED SURFACE.
A few years ago discussion was rife as to the relative
merits of fiIm and plates. Film has now been so per-fected that its satisfactory use for general work isscarcely questioned. It is so light and compact that agreat many exposures may be made conveniently on
an afternoon's outing. Although a nunrber of exposures
with plates would mean considerable weight an-d bulk,
plate ca'neras permit focusing upon the ground glass,
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1II
THE AMATITUR PITOTOGITAPTIER'S MANUT1L
.;
or in other words, the picture to be seen before it is {.{ taken. This certainly is considered by many to be
j necessary for fine work. The film pack adapter with
the film pack in a piate camera has the advantages of .ij
both but forvarious reason has not come into general
use.
The speed at which a sensitized surface is affected by
light was most accurately measured by two English-
men, Hurter and Driffield. "H and D" is the standard most cornmonly used. The value 200 :i.ssigned by these
two scientists is the standard for a sensitized surface
for ordinary use. H and D 200 is equivalent to the Wynne Scale of 111. The demand for speed film is
not made by the best informed photographers since
this film (about H and D 250) increases the speed only
about 25 per cent. For greater speed consider the use
of a faster lens.

CAMERA ADJUSTMENTS.
Some cameras have various adjusbments for special
work and for convenience. Of these the rising and
falling and also laterally sliding front is perhaps the
best knorvn. Suppose a picture is desired of the seconcl
and third stories of a building across the street or of an object to one side where it is not possible to place
the camera directly in front of it.
If we point the camera directly at the object, the surface of the film or plate will not be that of the
object. Then the top of the building will seem to slope back, or when pointed at an object to one side. the
further side will seem to recede. By shifting the front
and accordingly the lens, the distortion is avoided. At
the same time the desired objects have the correct
importance in the picture. By standing back a proper
distance these objects could of course be correctly rep-
resented in the picture but the amount of foreground or
of side view would be excessive.
In using the rising and falling or laterally sliding
front the lens is no longer centered upon the film or
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nlate. The finder then no longer shows ttrose objectsfnat *itt appear in the picture. qith..a plate -c-?$,era athe Eround- ilass affords certainty in its use' wrth -.;*ffi T[-i. .'t""v advisable to remove the back a'diii;;i;."; ;;o""4 elass" where the film u-ould be and test
ifr"- frorfi -in vaiious positions b-efote attemp^ting .ntty;;;";";";. with either camera the distance of the lensto'opposite sides of a plate.is not the same after it is
i6-fige" centered. The discussion on page .9. showed with proportionately. increaqes"oftow alpttr^workingof focus is^ desira- Consequent^lv.!! apertures.smaller
ble to use a sl-ow-speed as f22 or f 32 (q.- S. .32 oru. S. oai toi tnis *oik. A time exposure with a tripod
is then necessary.
Before closing the camera be sure to return the lens to-itso"Gi""i-poiitiofi-and sirice otte"wile the bellows would not foldpro"perly might be ruined.
When the lens is used at a large working aperture,
the depth of focus is conespo-ndingly small.. Thiq dl1-
i"r""." in distance from the lens 1o opposite sides ofthe nlate. makes it possible to have one side sharply in
focui and the other indistinct. On the better plateeameras an arrangement gets around Lhis difficulty by .
changing the angle between the bed of the camera andih" i.rrFuce of ihe fiIm or plate. Bi' tilting the backiiinttti.v io that the distance [o either side is more nearly "ttte picture at both sides may be brought intoeqfiat,
;li;; rocus.- rrri. i.ite the Siving Back' Whilethis iilting may seem contradictory".Joi '"c- the s-tatementson.l"r the'rising, falling and laterally sliding front, it is
is correctly slated as is possible rvithout becomi-nginvolved in iens technicalities. When the two principles
seem to conflict, the image upon the ground glass will
show the best course to follow.
After an operator has set his camera level upon atripod and has brought it into focus, he often finds that
a vertical picture would be preferable to the horizontal
one he had planned and vice-versa. The Revolving
Back allows this change r,vithout the difficulty often of
resettinE the camera and focusing. Only the better
equippeil Seneca Plate Cameras have this improvement.
A rack and pinion allows the bed upon some--cam-eras
to be extended. The minute movements possible both
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THE AMATEUR PIIOTOGRAPHER'S MANUAL
forward and backu'ard enable the operator to bring the
image upon the ground glass into the sharpest focus
with ease.
When the bed can be extended a considerable distance
it is possible to use lenses which are in focus a greater distance from the film or plate, or in lens terms, of
greater focal length. A lens of greater focal length
upon the same size plate folms larger images of the
same objects upon the ground glass bhan one of lesser
focal length and includes objects rvithin a narrower
angle. Photographers use these lenses to photograph objects at greater distances where it is not possible to
place the camera in a particular spot. For instance, to
photograph a house on the bluff of a river, the camera
would have to be placed upon the oplrosite bank. With
plate cameras of the type of the Seneca Nos. 8 and g
fitted with the Svmmetrical Convertible Lens, remove
the front combinltion of the lens and focus with the rear combination alone. In this case use the middle
row of figures after the letter B I( for the speed of
the lens as the working aperture, as the relation of the
lens opening to the focal length has been changed.
With a iong extension camera of the type of the Seneca
No. 9, a still longer focal length is possible by using
the front combination alone. Remove the back combi-
nation and put the front combination in its place. Focus
as before using the lowest row of figures after the
letter F T for the lens speed.
Photographers also find it necessary at times to include objects at a wide angle as banquet scenes, etc.
A lens of short focal length is used which is commonly
called a Wide Angle Lens. Although special lenses of
this type are upon the market, any lens for a smaller
plate and consequently of lesser focal length may be
used. In this case the lens cannot be used at its greatest working aperture. It must be stopped down
until the ground glass shows objects in the extreme corners of the plate to be in focus. Just how such a
lens covers a larger plate at a smaller working aperture i
would necessitate a discussion of the laws of ontics ,iil
altogether too extensive for manual of this kind. f,
i
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TIIE AMATEUR PHOTIOGRAPIIER'S MANUAL
CAMERA ACCESSORIES.
The accessories of a carr'era are generally well under-
stood by the amateur and semi-professional photogra-
phers. For the sake of certainty their use may be
briefly described. The plate holder must be loaded and
unloaded in the dark room. It must not leak light in
the light trap. To test the light trap place a corner ofthe slide in the slot where it is regularly slid and bend
the slide down slightly to force the wood cross strip up.
The plate holder is not safe if it is possible to see a
light space for an appreciable distance (an inch or so)
upon either side when held to the light. Serqeca plate
holders have an improved device to prevent leaking.
A fllm pack adapter occupies the sarne position in aplate camera as the plate holder. It accommodates a
film pack which can be loaded or unloaded in daylight.
The light trap may be tested in the sa,me way as upon
the plate holder. Seneca Adapters have no hinges to
get out of order and are so constmcted that they do
not cut off a portion of the picture.
A tripod is almost indispensable for time exposures,as it ailows the camera to be placed at will. Select
one heavy enough to hold the camera r"igidly. One too
light allows the camera to vibrate unnoticeably butsufficient to make the picture indistinct especially in
outdoor work where a breeze is liable to be stirring.The No. 400 Seneca Metal Tripod 'will support film
cameras as large as the post card size. For largerplate cameras it is advisable to choose a heavier wood
tripod of the sliding or compact type and of the size
recommended in the catalogue.
A supplementary lens is a small glass cap which fits
over the front combination of the lens u-pon any camera.If the one purchased seems entirely too large, just bend
in the prongs in the rim until it flts snugly. Each kind
changes the lens so that pictures of entirelv different
character may be taken. Be sure to foilow the accom-
panying directions carefully since the general directions
do not apply.
A portrait lens takes pictures with soft lines as are
usually present in the portraits of professional photog-
raphers. It allows large bust portraits as close as two
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THE AMATEUR PHONOGRAPHER'S MANUAL
and one-half feet. The focusing scale no longer applies.
The Wide Angle Lens does exactly lvhat its name sig-
nifies. The angle of view for the lens is widened, each
separate object appears correspondingly smaller. A
Telephoto Lens is the opposite of the Wide Angle Lens.
It narrows the angle of view and mal<es each separate
object appear correspondingly larger and is suitable for
photographing objects at greater distances. An Enlarg-
ing and Copying Lens helps the reguiar lens photggraph
writing, printing and drawings and enlarges slightly as
it copies. A Ray Filter gives finer effects to landscap_es
than- the ordinary lens unaided. Esilecially when the
sun is shining, the yellowish rays of Lhe sky change the
film or plate much faster than the green rays of the
grass and foliage. The yellowish glass of the Ray Filter
holds back (really screens out) the yellowish rays of
the sky and allows the green rays rnore time to make
their impression upon the film or plate. Consequently,
the contrast between the sky and folia.qe is not so great.
The picture is more pleasing to the eye. A Duplicator
covers up one side of the lens and allows a picture tobe taken upon only one-half of the film or plate. Then
the Duplicator is turned halfway around so that the
other half of the film or plate may be taken. This
allows the ingenuity of the operator a considerable
rang'e for freakish and startling effects such as a person
sitting beside himself, wheeling himself in a wheel-
barrow, etc.
OUTDOOR EXPOSURES.
Correct outdoor exposures vary so mueh with theconstantly changing conditions of light that it is wellnigh impossible to establish any fixed rule. It is more
proper to mention those factors which make such a
course necessary.
First of all, consider the subject. If a picture is
desired of a boathouse upon the edge of a lake, greater
importance should be placed upon the boathouse than
upon the lake or a motorboat perhaps going past. Ifthe boathouse is dark, it will take longer for the details
to become plainly impressed upon the fllm or plate than
the details of the lake or boat. Even though the por-
tion of the picture in which the lake appears is greatly
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THE AMATEUR PIIOTOGRAPHER'S MANUAL
-overexposed, thg success of the picture will depend uponhow correctly the picture represents the boalhouse as
it actually appears. If the picture is desired of the
boat on the lake, chief consideration should be sivento that. The exposure should then be shorter aJ the
light in an open space and from an object light in coloris more intense.
Secondly, watch the background. If this boathouse
stood beside a grove of trees, the green foliage would
make the background -it stood much darker than if 'Waterbefore a_n open field. especially reflects the light
and makes it more intense. The action of the light
upon the film or plate is consequently more rapid. An
exposure should accordingly be shortened. On the other
hand street scenes must be exposed longer as tall
buildings lessen the intensity of the light.
. Thirdly,.the int_engity qf the light varies according to
the condition of fight. If_the sun is shining brigliily,the light is very_ intense. Even an atmosphele so-hazy
that the sun will barely cast a shadow wil-l make neces-
sary an, exposure . twice as great. - Ligh_t clouds _andheavy clouds require exposures under otherwise iden-
tical conditions considerably greater. The air at high
altitudes is rarefied and makes the light more intense.
Mountain views of beginners are tluite liable to beoverexp_osed. In certain sections where the air is veryclear, the light is also more intense and exposures
should be shorter.
Fourthly, the time of day affects the intensity of-light and the proper length of an exposure. The light
is much brighter at noon than in the rnorning or after-
noon. Direct sunshine just before sunset is compara-
tively weak and requires a longer exposure than at
noonday.
- nifthl-V, the season of the year changes the properlength for an exposure. The sun's lighl is much iess
intense at midday in the winter than in the summer.
$i*t]oly, latitude affects exposures, but only for con-siderable distances. A few hundred miles wilt not
make an appreciable difference.
As a rule to follow, set the exposure at 1/25 secondand f 16 when a picture is desired between ten and
three o'clock on a bright summer day in the latitude of
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THE AMATEUR PIIOTOGRAPIIER'S MANUAL
the United States if the ob.iect is under ordinary condi-
tions. Before ten and after three change the diaphragmstop to f 11.3 or U. S. 8. During the middle of hazydays when the sun is barely qlrol.rg^ enougl to cast ashidow, use L/25 and f 11.3 or U. S. 3. Earlier or later
in the day, use the same shutter speed with the- nextlalser openinE. With light clouds a speed of f 8 or
U. -S. 4 is usually necessary under ordinary conditions
for a snapshot (shutter at 1/25 second).- These areonly geneial hints, it is bette.r,to depend upon one's
own experrence as soon as possrDle.
To an amateur who has difficulty in gauging his
exposures, an exposure device is especially useful. One
like the Seneca Simplex Exposure Scale will show the
correct exposure under all kinds of conditions and is
still conveniently. carried inJhe pocket.^.A description
appears upon inside cover. The Seneca Simplex Expos-
ure Scale takes into account only the more ordinary
conditions but will guide the user to the proper lens and
shutter speeds.
INDOOR EXPOSURES.
Indoor exposures must always be taken by timeexposure. Snapshots are sure to be a failure. The
following tables are figured between the hours of 10:00
A. M. and 3:00 P. M. with the 16 diaphragm stop. If
f 11.3 or U. S. 8 is used, allow only one-half the time;
if t22 or U. S. 32 is used, allow double the time. Byreferring to the discussion of definition on page 5, it
will be seen how a smaller opening 8:ives sharper pic-
tures. Upon the whole, the 16 stop is the most satis-
factory for interior work.
White Walls and More than One W'indow
Bright sunlight outside 4 seconds
Hazy sun 10 "Cloudy bright . . .. .. 20 "Cloudy duII . .. 40 '3
White W'alls and Only One Window
Bright sunlight outside 6 seconds
Hazv sun 15 33"Cloudybright ......30Cloudy dull 60 't
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THE AMATEUR PHOTOGRAPIIER'S MANUAL
Medium Colored Walls and Hangings and
More than One 'Window
Bright sunlight outside 8 secondsHazy sun .. . . . 20 '(Cloudy bright ...... 40 "Cloudy dull 80 "
Mediurm Colored W'alls and Ifangings and
Only One Window
Bright sunlight outside 12 secondsHazy sun ..... 30 '(
Cloudybright ......60 "Cloudy dull ...120 "
. Dark Colored WaIIs and Hangings and 'Window More than One
Bright sunlight outside. . . . . 20 seconds
Hazy sun 40"Cloudy bright ..Cloudy dull . ...2 minutes, 8040
Dark Colored Walls and Hangings and
Only One Window
Bright sunlight outside 40 seeonds
Hazy sun 80" .3Cloudy brigh{ . .2 minutes, 40
Cloudy dull ..,. .. . . . . .5 " 20 ..
, \----- LANDSCAPE SUBJbCIS.
Qf the {nany kinds of pictures, landscapes are theebsiest and most satisfactory for beginneis. Specialhints are unnecessary, since it is merely ordinarv pho-
tqgranhV.-The users should bear in mind that tho angle
of view of a lens is much greater than that of the eye.
Consequently, unless the user gets mueh closer than-at
first seems necessary, the picture of a cow in thepasture which the beginner plans will show a broad
expanse of pasture with a diminutive cow in the back-ground'
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ffiE AII,TATEUR PHOTOGRAPHER'S MANUAL
MOVING OBJECTS.
Moving objects are constanlly *-o.titg acrofs,thq filne or nlate -duriirE an exposure. The distance will be twrce
ir ?"""t-a""ifrg att e'xp-osure o-f .l/25 second as during 1/50 se"cond. if ttre distance is not too great,
it-*iii""e-"t U" visible to the naked eye, a,n{ the,picture technicali- tiifi r""-"ii sha"p. Wittrout going further into ii;,"1.t il;ad- just how mlovil-s objects.mav be taken wifhout being biurred, or, in phbtographic terms, with-
o"i-;.tto*i"i motion.t' Ordiirary mgtlon is "stopped" bv an expoJure of. L/25 second. More rapid -motion
should be caught at an angle of about forty-five degrees u"a a littlJ distance. A distance of twenty-fiv-e feet an "ii" exposure of.7/50 second is satisfactory for ""aordinary foot race.
HOME PORTRAITS.
The charm of photographs, especially portraits -of the children and other members of the fannily in the house,
is takins Ereater and greater hold upon picture-takers.
Wittr orEin-arv hand caireras, its possibilities are limited
to-the uJe of ihe supplement-ary portrait lens mentioned
o" naE" ff . Senecld View Carir&as permit any of- the resila-r portrait lenses used by portrait photograp-hers
tone attached and operated successful.lfl. Aside. from
the correct use of the camera, the most rmportant- rea-
i""ur to be borne in mind are the position of the subject
and the lighting.
Seek natural and agreeable poses. The popularity of
home portraiture is growing because the- subject is at
ease in'the midst of alcustomed surroundinEs and gives
a "naturalness" to his poses that is sometimes lacking elsewhere. Even the gfown-up will without knowing-it chair pose same he in the because is sitting easily !v -other week. day of the any upon as window the same
A -meantpose may be natural but sfill disagreeable...-By this is that many poses of our everyday life show ourselves as we really are but nevertheless are not what we should like io show or give to our friends.
Exnressions of anEer, fright or fatigue are usually not
ple^asingly represented in the photograph.
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THE AMATEUR PHOTOGRAPHER'S MANUAL
For successful portraiture the light must be soft.
Mgleqv-qr, the subj-ect ryus! be situatdd so that the ligh[ will fall upon those feafures which are to be m-ost
porch or prominent -in the portrait. If a curtain on a tree outside do not lessen the intensity of the light vrhen the sun is shining directly in, the light will-be
too harsh. The light portions will ne correspondingly
too light and the shaded portions too dark foi a satis- factory portrait. For a northern exposure or an expos-
ure on a_cloudy day,_the problem of regulating the light
is greatly simplified. It is better to have-the light j back of the camera, but since the subject must be rea-
sonably_ close to the window, this is not always possi- ble. When the camera is at one side, keep it-pointrng
away from the light as much as possible instead of towards the light. One's visits to photographers' studios will furnish good ideas for the proper lighting.
. FLASHLIGHTS.
The pos_sibilities of flashlight photography -th-e are oftenoverlooked, allq some amateurs considlr flashlight
process too -djfficult_or dangerous to attempt. Ftash-light material can be purchased almost anywhere in
such convenient forms as the Actino Flashlight Cart-
ridge,_a4d although it is highly inrlammabli, it can
nevertheless be used _with perfect safety by adheringclosely to the printed direclion on the package. The
first step in making a flashlight photograph isto focusthe camera on the subject; if a group is to be taken,
have them as close together as is conv-enienflv possible.
Next set the lens at 16, turn off the lights and 6pen-camerathecamera shutter. One light to the rear of thewill not affect the film and will help during the neces-
sary _arrangements. The flashlight should now beplaced a.! s!4e and back of the cam_era, and as high -oneas possible. This is the proper and most effectiiearrangement of the light. If convenient, it is also well
to place a white paper or cardboard reflector back of
the cartridge.
_ Nothing remains but to explode the flash and closethe camera shutter. Danger-from burns or fire may -be entirely eliminated by the use of the Actino Flash-

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