Exakta 35mm Guide

							888@ ##Above: Completc cassette (left)rnd its component parts.(8elow: Handle thc film by itssdtes.
HANDLING, trVINDING, TRIMMING 35 mm. FILMshould be perfectly dry, clean and dust free. Only a spotless,clean negative will produce the desired result! -
Whgn using bulk film in loading cassettes, the edge of thervork-bench can be marked with notches or drawing-pins toindicate various distances, let us say for 12,24,36 eiposuresof film. This considerably sirnplifies the measuring-of filmlengths in the darkroom.
The fihn ends need trimming. At the beginning of the rollof film, make either a straight or wedge-shaped cut for thecentre spool of the cassette and measure off the requiredlength of film (see table belorv). At the end of this, rnake thecurved cut for the take-up spool (page 35). The curved cutshould start between the ninth and tenth bottom Derfora-tion-when emulsion is towards you-and must not gothrough a perforation hole.
-The ready-cut film is now spooled on the centre spoolof the cassette, as described on page 37. One lvill have to
TENGTH OF FILM REQUIRED FOR ANy NU/VBER OF EXPOSURES
Abovc: The film ends heve to betrimm€d to shape.
Right: How toettach the filmto the spool.
Right: Windingthe film on thespool.
Selow: Cessette inserted in tlodellle, llb and VX for cassette-to-
Number Length of Numberof Film ofExposures Required Exposures
Length of Number Length ofFilm of FilmReguired Exposures Required
Eelow: Cassette inserted in theExakta for cassettc-to-sDool use.(Exa is similar, but with leedcarsette on the left.)
12345678910111213
in. cm.11* 3013+ 3415 3816* 4117t 4s1e* 4920* s322 5623* 602s+ 6426t 6828+ 7230 76
In, cm.14 31t 8015 33 8416 34+ 8817 36* 9218 37t 9619 3et 10020 40+ 10321 42 10722 431 1t123 4s 11424 46+ 11825 48 12226 49+ 126
ln. cm.27 sl 13028 szi 13329 54 13730 ss* 14131 57 14s32 s8+ 1-{833 60 15234 61+ 1s63s 63 16036 64+ 16437 66 16738 67i- 171Including trimming
M#irr:*#ry
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							m_4ke sure, while winding on, to hold the film only by itsedges.When winding the film on and off, care must be taken thatno great pressure is put on the film, and that the film-endsare not squeezed when drawing through the hand. Failureto take the first precaution may result in fogging, while
leglect of the latter precaution may give rise to peculiarkinds of exposure effects known as lightning flashes.These are due to electrical discharges, and appear as dark,zigzag lines running from the edge of the film towards thecentre of the picture.
Loading Cassettes
The majority of cassettes consist of a centre spool whichis in a shell with top and bottom cover. The film leaves theshell by a light-trapped slot (the cassette mouth). The centrespo-ol can be,removed from the shell by rernoving either topor bottom of the cassette, according to the construction oTthe particular container.Most of the cassettes are actually intended by theirmakers to be used once only, and rviih the film originallysupplied in it. However, fiovided they are reasSnablyrobustly made and the light-trapping velvet slot is in goodcondition, these cassettes can be reloaded many times, andwill give perfectly satisfactory results-z/ handled carefutly.
Cassettes with Bulk Filrn or Darkroom Refills
1. Work in the darkroom in appropriate safelight.2. Prepare film.3. Open cassette.4. Fix film on centre spool.5. Wind film on centre spool.6. Insert centre spool into shell; the first 2 in. of film hasto project from the light-trap.7. Close cassette.2. As described on page 34.3. As described above.
4. If the centre spool is fitted with a film catch, thread the taperedend of the film into it. In cases where the centre spool is fitted witha spring, thread the end under it and fold it sharply back. If thecentre spool is without any suitable fitting to hold the film, it hasbeen proved best to wind a 1* in. (4 cm.) piece of cellulose taperound the centre spool, so that on either side about * in. tape isused to secure the film (see page 35).
7. Where both top and bottom covers are loose, it is essential to fixthem to the shell, preferably with a length of adhesive cellulose tape.
Cassettes with Daylight Refills
1. No darkroom is necessary.2. Remove film wrappings and label of refill.3. Open cassette.4. Introduce refill into shell of cassette; the first 2 in. ofpaper leader has to project from light-trap.5. Close cassette.6. Pull out paper leader and 2 in. of fiIm.7. Cut off paper leader.
4. The actual centre spool of the cartridge is not needed.
5. See No. 7 above.
The Choice of Black-and-White Material
There is no such thing as a best film for any or everykind of picture. Each type of film has certain characteristics,especially with regard to colour sensitivity, speed, gradation,latitude and, more particularly, grain.
COLOUR SENSITIVITY. Practically all 35 mm. filmsthat can be used in the Exakta are sensitive to all colours.They are what is known as panchromatic.
INFRA-RED FILM. Infra-red film is a negative material which,unlike the panchromatic films, is made sensitive to infra-red rays,which are not visible to the human eye. Special applications of thismaterial : black-out photography. long-distance shots, mist penetration,scientific copying and research work. It must be used with an infra-redfilter to cut out blue light, to which it is also very sensitive.
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							COPYING FILM. For -copying black-and-white objecrs (books,ledgers, etc.), a micro+opyingfilm can be recommendeil. It lias fin6grain, high resolution and contrast. For coloured originals there is apanchromatic type.
SPEED. The sensitivity of film materials to light in generalis expressed as a number of degrees, or as juit a nimber,according to the system used. The principal iystems are theAmerican standard (ASA) and the German standard (DIN).
Fpeed is._an asset, but it is a quality which must be piid forby possible disadvantages of the material in some otherrespect. To call the fastest film the best would be iust asfoolish as to select a racing car for daily motoring.
Slow films .are of lovr sensitivill reOuirine _comparatively greatex-pggurg. Their -main advantage-i_s the extremely fine grain, peimiitinga high degree of-enlargement without its granular structuie-becominEqplleasantll visible. - Such films also yiEld images of the greatesisharpness. On- the-other hand, these slow films aie not very Juitable[g{ goping with fast movement in other than exceptionilly goodlighling, nor for general work in poor light. Such filrirs are iatdd at40-80 ASA or 17-20 DIN.
Medium -speed films still yield a reasonably fine grain with goodgradation.-They are the most suitable material for ill-round pi-oto-graphy, other than in poor light. These films are rated at 80-160 ASAor 20-23 DIN.
-last films with somewhat coarser grain (still acceptable for reason-able degrees of. e-nlargement) will cope witir mosf fight conditions,including poor light and interiors in favourable conditi6ns. This is th6right film for the -photographer who wants to be prepared for theunusual, to arrest fast movement with high shutter speeds, as well asshots in poor light. The ratings are 200-400 ASA or 2+-ZtnlN,
- U-ltra fast films are primarily intended for high-speed sports shots indull weather, interior s{rapshots in poor light, hight pho-tography andill-lit stage pictures. These films are speciaiist lypis for-condltionswhere normal materials are totally inadequate. They should not bcused for general photography. The high speed is alhieved at someqo_sq in d-efinition_and graininess. Speed ratings range from 500-1600ASA or 28-33 DIN.
The above speed figures are based on the latest ASA Standard forfilm. speeds, These figures, when used on the exposure meter, giveminimum gorrect exposures, to make the most of the versatility oflhefilm and of the image quality. They are also the figures quoted by mosttilm manulacturers. Sometirnes, films are, however, still rated accordingto earlier standards which in effect incorporated a generous safet!ftctor against-under-exposure-by the simple process of overexposingfilms about 100 per cent (well witirin ttre exposure latitude of mos[black-and-white films). So you may come across films apparently onlyhalf as fast as others of similar type, because of ttris difference in ritingJ.The table on this page indicates the current film speeds to be usidwit! the exposure_met-er, even if the film packing gives a lower rating.This-applies to black-and-white negative materials only; speed ratingmethods have not changed for colour films.
35 mm. BTACK-AND-WHITE FILMS
Speed in ASAand BS ArithmeticSpeed in ASAond BS Arithmetic
Adox-Adox KB 14Adox KB 17Adox KB 21Adox KB 25Adox UKBIT Reversal
Agfa-Agfapanlsopan lFlsopan ISS ...Agfapan 1 000Dia Direct 25 Reversal
Ansco-Super Hypan
408020050080
1t804001 000
Kodok-Panatomic XPlus XTri-X Pan ...
Konica-Konipan S ...Konipan SS...Konipan SSS
Orwo, Wolfen-NP 15NP 20NP 27
Perutz-P14Pt7P 2l
40125400
100200400
I80400
408020050050
4080200400
40160320640
50125400
o-h
a
J
FFB
Ferrania-P24P30f 55P35
Pan FF,P.4H.P.4
Tura-Pan 14Pan 17Pan 21Pan 24 
						

							CONYERSON OF FILM SPEED SYSIEMS
A5A & 85Arith.(New) +
*Also Weston Master lll and later meters.
In this table each value represents twice as fast a film speed as theone immediately above it.In some systems this doubling of film speed means increasing thespeed number by 3 each time (B.S. Log. DIN), while in others thefilm speed itself is proportional to the exposure required (ASA).GRAIN. Silver grains themselves form the picture in the emulsion.To the naked eye they form a cornpact, dark mass; but under tl.remagnifying glass or microscope the separate clumps of grains arevisible. Obviously, il the grain of a small negative rs coarse, it will soonbecome visible by moderate enlarging, and the finer the structure ofgrain the more enlarging will it allow without showing any unpleasantgranular effect in the print. As a rule, it can be said tliat tlre grain sizeis in direct relation to the speed of tlre film (page 40). The faster thefilm, the coarser the grain and vice versa. It may be pointed out at thesame time that the grain can, to a certairt extent, be influenced bydevelopment (hence, fine-grain developmeni), correct exposure, choicenf nancr clnGRADATION. Each filnr has an ability of its own to reproducevarious degrees of brightness on its eri.rulsion. If the film can reproduceonly a short tone range in the subject, we speak of a higlr contrast orhard negative material. If it is able to reproduce a wide range of tonesin the subject, it is known as a low contrast, or soft filrn. Cenerallyspeaking, low-speed films of fine grain possess a higher contrast thanfast films, rvhich are softer.LATITUDE. Latitude is the ability of the film to yield usable nega-tives, even with a certain amount of under- or (more often) over.exposure. Films praised for particularly wide latitude may facilitateexposure. but are Iikely to have less resolving power, causing lossof definition which in big enlargements is just as unpleasant asgraininess.Our negative material has a number of additional properties whichhelp towards good results. There is a special protective coating, a
hardened gelatine layer on top of the actual sensitive layer whichprotects it against scratches. The base has been coloured, as a rulegrey, in order_to avoid reflection of the light coming through theemulsion and thus causing halation.
Colour Film
There are two types of colour film for the Exakta. Thefirst type is negative colour film and produces negatives incolour. These negatives resemble ordinary negatives-thedark parts of the subject are light and vice versa-and inaddition the colours are reversed. Thus, blues are yellow orbrownish, reds are blue-green, and greens are reddish.These colour negatives are then printed on a similar kindof material to give colour prints or colour enlargements.You can also use these negatives to obtain black-and-wtriteprints in the normal way.The second type of colour material is reversal fi.lm andproduces positive colour transparencies on the film whichwas sxposed in the camera. These transparencies can thenbe viewed by transmitted light or projected through aprojector and colour prints can also be made from them.Both kinds of colour film are available in two types,balanced for daylight or one of several artificial light sources.
EXPOSING COLOUR FILM. The exposure latitude ofcolour film is very small. It is therefore important to ascer-tain the exposure time accurately with a reliable photo-electric meter. Underexposed and overexposed films notonly produce dense or weak transparencies, but also thecolour values are distorted. Overexposure produces pale,diluted colours; underexposure gives hard, degraded colours.Avoid great contrast such as deep shadows; preferablyhave the light coming from behind you.For photographs by daylight, use daylight type film.Load your camera with artificial light film when takingpictures indoors by the light of high-power electric bulbs orPhotofloods. Daylight fllm may be used in artificial lightand vice versa with the special conversion filters recom-
ASALog(New)OJLog
to2o2o405050708o9o
56
t5501002004008001 600
16019220250280310340370400430
691215182121273055
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							35 mm. COLOUR FlU,tlSDISPLAYING THE COLOUR PICTURE. The colourtransparency can be viewed in a variety of transparencyviewers. The simplest consist of a magnifying glass set in aframe into which the picture can be inserted. If the vieweris held against a lighied background, the picture appearsenlarged and well illuminated. More elaborate viewers havean artificial light source of their own.The most satisfactory way is to project the transparencyin a slide projector which will throw a large picture on to aprojection screen. Transparencies will also yield colourenlargements.The colour negative can be printed or enlarged directly oncolour paper to produce a colour print of any size. Alterna-tively, the colour negatives can be printed on positivetransparency film to produce colour transparencies forviewing or projection in exactly the same way as explainedabove.
Specd in ASA Proccssin3ond BS Arithmetic
Ncgotivc EmulsionsAgfacolor CNSFerraniacolor N27Fuiicolor N 100Kodacolor XOrwo Color NCl6Perucolor
Rcyersol EmulsionsAgfacolor CTl8Agfacolor CK20Anscochrome 64Anscochrome 1(X)Anscochrome T 100Anscochrome 200Anscochrome 50OEktachrome XH.S. EktachromeH.S. Ektachrome BFerraniacolor CR 50Ferraniecolor Dia AFerreniecolor Dia.28Fuiichrome Rl00Kodachrome llKodachrome llAKodachrome XPerutz Color Ct8
UniversalUniversalUniversalUniversalUniversalUniversal
DaylightArtificial lightDaylightDaylightArtificial lightDaylightDaylightDaylightDaylightArtificial lightDaylightArtificial li3htDaylishtDaylightDeylightArtificial lightDaylightDaylight
80401005432oo
UUMULU
50806410010020050064160255040500025.t06150
Mi4M1-,1MMl,tUUUUULMt4MMM
PROCESSING: M-films can be processed onty by the maker; L-films can bcprocessed only by an approv-ed laboratory througli e photographii detlcr; U-filmrcln be procetsed by melns of special processing kits.
me4ded by the manufacturers. For flash pictures, usedaylight colour film with blue-tinted flash bulbs.For distant landscapes, scenes on hazy days and at highaltitudes, a haze filter should be used tb prevent a bluiihcast. This filter is also useful when using eltctronic flash toproduce .warmer tones. The filter doei not call for anyrncrease ln exposure.
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							EXAKTA LENSES
A wide range of lenses has been mounted for the 35 mm.Exakta cameras. The standard lenses arc 2 in. (5 cm.) or2l in. (5.8 crn.).Some of these lenses weie, or are, marketed by the manu-facturers of the camera, some quite independently of them.For that reason one mav find Exaktas r.vith lenses not listedin this book.Lenses of any focal length from 20 mm. to 1000 mm. andof apertures up to .f1.5 can be interchanged with thestandard lens in any of the 35 mm. Exakta cameras.A most important feature of the construction of theExaktas is that, whatever lens may be employed, the correctimage and accurate focusing is obtained in the mirror reflexhousing. Consequently, no special finders are needed, asthis at the same time does away with parallax, no matterhow short or how long the focal length of the lens.This does not hold good for the auxiliary .frante fnderdevice. The frame finder is correct only for the standardlenses.The diaphragm on the Exaktas is adjusted by means of amilled ring engraved with the aperture figures on the lensmount. Pre-set or automatic aperture setting lenses aresupplied with recent models; their manipulation is describedon page 29, No.4.The mounts of the lenses are arranged so that accessories(filters, supplementaries, lens hood) can be slipped on orscrewed in.
Setting and Changing LenscsThe 35 rnm. Exaktas use lenses in a focusing mount. That is to say,the lens itself is fitted with a helical focusing ntount. When screwedright back, it is in the infinity position.Focusing for nearer distanccs rs done simply by tuming the lensmount to screw it forward.
The focusing mount bears a distance scale, as a rule in feet. some-times in metres, with an index indicating the distance to which thelens has been set.To remove the lens, it has to be held firmly in the left hand. whileat the same time pressing the lens catch liglitly with the right handand simultaneously turning the lens firmly to the left. After iurning afew degrees, it will be found that the lens disengages and can be lifledfrom the camera body.To insert a lens, this procedure is reversed. The lens is held into thetubularmount of the camera body, care being taken that the red doton the lens comes to lie opposite the red dot on the camera body.Now the lens and mount are turned firmly to the right until the lenscatch is heard and seen to slip into the catch on the lens mount.A depth of field calcuhtor is engraved on the lens mount. On eitherside of the distance indicator the aperture values will be found engraved.After focusing with the mirror reflex arrangement or by setting theindex mark to the distance required, one can read off bpposit6 theleft-hand -stop the -depth of field to the foreground and the right-handstop the depth offield to the background (see page 53).
The treatment and care of lenses is a matter of importance.On account of its chemical composition, optical glass ofhigh quality is susceptible to the influence of moisture, andfor this reason touching the glass with the fingers should beavoided. When not in use, the lens should be protected byputting bn the lens cover or at least by a lined case. Sincbcomplete protection is impossible, the lens surface shouldbe cleaned occasionally with a clean, soft chamois leather.
The Choice of Lenses
The Domiplan f2.8 50 mm., Tessar f2.8 50 mm. andOreston fl.8 50 mm can be regarded as standard Iensesfor the Exakta and the most suitable for general use.It is wrong to assume that the high correction of the largeaperture lenses enables one to use them invariably at theirfull opening. It will be appreciated that the depth of fieldcan only be comparatively small, so that more often thannot stopping down becomes necessary. Large apertures are,however, useful in adverse lighting conditions and they alsoensure a bright focusing image on the ground-glass.The possession of one or more of the longer focal length
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							Ienses may tempt the owner to use them more frequentlythan necessary. It must be remembered that focusing a leniof long_ focal length has to be done more accuratEly, as,agaln, the depth of focus is considerably more limited thanwith lenses of shorter focal length. At the same time, owingto thelonger axis, slow exposure speeds of l/50 or l/25 wit[these lenses tend more easily to camera shake-if a rigidtripod is not used-than with lenses of normal focal lenpfih.
All Exakta lenses may be used in enlargers fitted with anappropriate bayonet flange.
All modem lenses are coated. This consists of the application of amicroscopically fine deposit of some inorganic substani:6 on the slasssurfaces, which reduces considerably the light reflection between ltassto air surfaces in the lens. The scatter of light which impairi thecontrast of the image is eliminated, giving a more brilliant negative,especially in the regions where the tones aie most subdued and-rvher6consequently brilliance and contrast are most needed.
Standard Lenses2in.f2.8 DOMIPLAN: a three-element triplet construction, of goodperformance aqd- colour-correction suitable for all generai phloto-graphic work of the amateur photographer.
2 in. (5 cm.) TESSAR f2.8: a universal four+lement lens suitable forall average- expo^sures, including landscapes, portraits, street scenes,g-!c., 9ve! in unfavourable light conditions. It has particularly evenillumination all over the negative and good colour co-rrection. -
2 -rn. (l- cm.) ORESTON f 1.8: a six-element lens may be consideredas the all-round lens of wide aperture for the Exaktis. Apart fromave-lage-subjects of all types, the particular field of its application is inartifi-cial light work, interio-rs, the theatre, as well as phbtography ofrapid mov-ements. The definition is to be considered- as vEry- g6od,even with full aperture, and it has great brilliance and coverinj power-The correction remains undiminished at smaller apertures.
O ? in. f2. DOMIRON: a six-element Gauss-type construction, ofhigh definition and of similar performance to the-Pancolar. but withunu-sual long extension permitting ultra-close focusing down to 34 cm.: 13* in.
Earlier Exakta models were fitted with other lenses, such as 58 mm.f2Biotar (similar to Pancolar),58 mm./l.9 Primoplan, and others.
Wide-angle LensesWide-angle lenses have shorter focal length and shorv a wider angleof view than the standard lenses. The increase in the field covered ascompared with the standard Exakta lenses is indicated in the table onpage 66.Wide-angle lenses rvill be found particularly useful for taking interiorswhere as wide a field as possible should be reproduced, also for takinglarge groups, for photographing in narrow streets-in fact, everywherewhere the distance subject-camera is restricted. Perspective, as depictedby a wide-angle lens, appears the more exaggerated the shorter thefocal length of the lens. The exaggeration of perspective of the wide-angle lenses can be put to good use in special cases-for example, toenhance the foreground of a composition or to introduce sonte otherdeliberate distortion. One has to put up with the fact that the illumina-tion towards the edges of negatives taken witl-r wide-angle lenses isbound to fall off to a slight degree. This can be offset (to son-re extent)by giving generous exposure times.
lVide-angle lenses for the 35 nurt. Exaktas:
Flektogon/4 20 rnm.Flektogon/4 25 mm.Orestegon/2.8 29 mrn.Lydith /3.5 30 mm.Flektogon/2.8 35 mm.Primagon/4.5 35 mm.
Long-focus LensesLong-focus lenses for the 35 mm, Exakta are either lenses of normalconstructioll, having a correspondingly long barrel; or telephotoconstruction, which permits a much shorter mount. The decrease infield compared with the standard Exakta lens is shorvn in the table onpage 50.Given the same size negative and the same distance between cameraand subject, the longer the focal length the larger is the reproductionof the subject. Long-focus lenses are thus particularly useful forfar-distance rvork, such as photographing mountains or architecturaldetails, where one cannot approach near to the object; this is also thecase when taking animals, sports photographs and portraits, where themellowed perspective which can be got with the lorrger focus lens froman increased working distance is pictorially advantageous. The dis-advantage of long-focus lenses is that they yield less depth of focus than
4748