Unblinking Eye
Eastman 5369 High Contrast Film

 

Eastman High Contrast Panchromatic Film 5369
as a Replacement for Kodak Technical Pan Film 2415

by Harvey W. Yurow Ph.D.

Background: As the 35mm bulk rolls of Kodak Technical Pan 2415 film (production discontinued 2003) wind down, the question arises as to whether any currently produced offering approximates the unique characteristics of this black–and-white film? Technical Pan belongs to a group of films produced in 35mm format and having ultrahigh resolution. This property is the result of a monodisperse  emulsion having extremely small silver halide grains, which goes hand in hand with high contrast. High contrast films are of three general types: 1.) moderately high contrast, i.e., gamma range of 2.5-3.5, with panchromatic sensitivity, including Technical Pan, 2.) gamma range of 2.5-4.5, with only blue sensitivity, such as Eastman Fine Grain Release Positive Film, used to prepare positive motion picture prints, 3.) Lithographic films of gamma around 9, either orthochromatic or panchromatic, including Kodak Ektagraphic HC Slide Film for making title slides. However, it should be pointed out that Technical Pan differs in degree from all of the others in two respects – its speed is considerably faster, to allow for pictorial photography at lower contrasts, and probably involves organic chemical supersensitizers (APUG), and it has extended red sensitivity. This film replaced two others, Kodak Solar Flare Patrol Film SO-392, with maximum sensitivity in the region of the hydrogen-alpha line at 656nm, and Kodak Photomicrography Monochrome Film SO-410, used for photography through a microscope, where specimens are often of low contrast (Kodak 1977).

Possible replacements for Technical Pan with regard to two unusual uses of interest, i.e., equidensity technique and reversal development (see below) should have the following parameters:

  1. High contrast – with a gamma range of approximately 2.5-3.5, which allows steep trough-shaped D log E curves (see below), which are pictorially more impressive for equidensity images, and which provide more dramatic diapositives with significant middle tone renditions by reversal processing.
  2. High maximum density – with a D max of around 3.0-4.0 to give deep intensity areas in diapositives that set off highlights, via the above two techniques.
  3. Panchromatic sensitivity- of use for reversal slide landscapes, in conjunction with a red filter, to emphasize skies and clouds.
  4. Sufficient speed rating – assuming the slowest reasonable hand-held exposure of an outdoor sunlit scene, this would be approximately 1/30 sec f2, or an exposure index of 0.5.
  5. Availability at a reasonable cost – as with Technical Pan, this will probably involve purchase in bulk rolls for reloading into 35mm cassettes. Minimum purchase requirement should preferably be in 100-500 ft roll size.
Balboa Park, by Harvey W. Yurow

Eastman 5369 Developed by Reversal

One comparison reported among Technical Pan and four other ultrahigh resolution films, especially with regard to speed, was that of Everhart in connection with astrophotography. Two of these films are of considerable interest for replacement of Technical Pan. One is Eastman High Contrast Panchromatic Film 5369, a so-called intermediate film used in cinematography in the process between  development of the initial negative and the production of release positive prints for public viewing. Eastman 5369 has been reported for three primary uses, one application being the  preparation of silhouette and traveling mattes (Beyer, Erland, Feiner, Kodak 1997, Trumbull). Films for this purpose require high contrast, high resolution, high maximum density, and very fine grain. The mattes produce the special effect of a moving person or vehicle against a distant, dangerous, or totally alien  background, such as is found in the “Star Wars” motion picture series (Brain). In essence, four images are combined via an optical printer onto one film, i.e., a) the background, b) the foreground figure or object photographed against a constructed, featureless bright blue background, c) a silhouette matte of the figure (recording as black) photographed with high contrast panchromatic film and a red filter against the blue background (recording as white), d) a reverse print silhouette matte of c), giving a white figure against a black background.
Balboa Park, by Harvey W. Yurow

Eastman 5369 Developed
by Reversal

Eastman 5369 has also been reported for special effects in direct filming of flash-cut (i.e., converting analog to digital) scenes in motion picture filming. For this purpose an exposure index of 6 has been used. Because of the high contrast of the film, exposures were bracketed and processing was modified (Kodak 2000). Further, when color negative film is shot and then printed on Eastman 5369, the B&W release prints produced have dramatic contrast and deep blacks (Cinematography.com). A rationale for producing a film in this way is as follows (Roger Ebert). Almost all B&W movies made today are shot on negative color film stocks, which have been greatly improved over the past 30 years with regard to film speed, granularity, and gradation as compared to black-and white negative film. Consequently, by shooting on color film and printing on various B&W print film stocks, different creative styles are more effectively made.

A second film tested by Everhart, and considered here, was Kodak Recordak AHU Microfilm 1460, its current incarnation being Kodak Imagelink HQ Microfilm. As compared to Eastman 5369,  speed, contrast, and red sensitivity are similar (Kodak 2009), but maximum density is considerably less (2.1). Similarly, Eastman Panchromatic Separation Film 2238, another cinematographic intermediate film, has a suitable D max, (>3.0), but maximum gamma of only 1.8.

Eastman High Contrast Panchromatic Film 5369, introduced in 1973 and formerly known as SO-389 (Anon 1973), is available in 35mm as 1000' rolls ($232) from the Kodak Motion Picture Film Hollywood Regional Center (1-800-621-3456) . This large roll can be rewound by hand onto 100' metal spools, such as Kodak S-83, for use in 35mm bulk film loaders. The procedure is somewhat lengthy in a changing bag, but considerably less so in a completely black darkroom where the large bulk roll can be supported vertically so as to freely rotate, with the metal uptake spool also aligned vertically. Interestingly enough, this film is about half the cost of Technical Pan when the latter was in production. A comparison between Technical Pan 2415 and Eastman 5369 is indicated below:

Table 1. Comparison of Technical Pan 2415 and Eastman 5369 (Kodak 2003, 1997)

Film

Exposure Index

Gamma Max.

Density Max.

Resolving Power
TOC 1.6:1

Red Cut-Off

Technical Pan

100-200

3.6

4.0

125

650nm

Eastman 5369

12-25 (estim.)*

3.6

2.9

250

625nm

*Overlay of the D log E curves for the two films indicates approximately 3 stops slower speed for Eastman 5369.  However, Eastman 5369 is reported to be 2 stops faster than Eastman Fine Grain Release Positive Film, another high resolution film.

An explanation for the rationale for requiring certain high contrast Kodak motion picture intermediate films is the following (Kodak 1936). In the cinematographic industry, the need for wide distribution necessitates production from the original processed negative film of a master positive as well as a duplicate negative, and subsequent release prints, the last named required for distribution among various movie theaters. For the master positive and duplicate negative, special emulsions are essential, which have high resolving power and a low order of graininess. For the latter consideration, the best results are obtained when the master positive is developed to a relatively high gamma and the duplicate negative to a much lower gamma, the product of the two gammas being approximately 1.0, to match the contrast of the original scene.

Experimental:Two areas in which Technical Pan excels are for production of equidensity slides (Yurow), and for formation of diapositives via reversal. For both of these techniques the relatively high contrast of the emulsion is essential for obtaining dramatic results. In the equidensity procedure, a developer containing 2-chlorohydroquinone and 1-allyl-2-thiourea (formula given below) results in a violet-blue negative image in conjunction with a brown positive image, and accompanied by clear border contour lines. The reversal development technique (Anon 2003) gives pictorial, continuous tone, high contrast slides with dazzling whites and deep blacks.

In Table 2 are indicated the exposure comparisons determined for Technical Pan and for Eastman 5369 for typical sunlit outdoor exposures. While both of these films have panchromatic sensitivity, the extent of red sensitivity differs. Technical Pan has Class E sensitivity - highest total red sensitivity, (maximum 640-650nm), with sharp cut-off beyond about 660nm,  but with low green sensitivity. Eastman 5369 has class D sensitivity – high values through green and yellow to about 630nm (Kodak 1960). In practical terms, with a Wratten #25 red filter to darken skies for diapositives, the filter factor for Technical Pan is 3, and 8 for Eastman 5369, as noted in Table 2. Substitution of light red Wratten filter #23A for #25 gives an outdoor sunlit exposure of  1/60 f4.9 and makes visual focusing with a single lens reflex camera somewhat easier.

Table 2. Exposure Values for Technical Pan 2415 and Eastman 5369

Film

Equidensity Exposure

Reversal Exposure (Wratten #25)

Technical Pan 2415

1/125      f/4.9

1/125      f/11

Eastman 5369

1/60      f/2.8

1/60      f/4

Balboa Park, by Harvey W. Yurow

Eastman 5369 Developed w/ Equidensity Developer

Development time for equidensity exposure with both films is 5.0 minutes at 20 C (formula given below). For reversal with Technical Pan, development is with DK-50 with 4g/l of added potassium thiocyanate for 12 minutes at 20 C, while for Eastman 5369, it is DK-50 with 3g/l of potassium thiocyanate for 8 minutes at 20 C , which correlates with its lower D max and gives satisfactory results. Reversal procedure for both films involves standard chemistry, with first development followed by acid dichromate bleach, subsequent sodium sulfite clearing bath, second exposure (to a photoflood with the film reel submerged under water in a white bowl), second development, and  fixer.

In Table 3 are given gamma values and maximum density values for Technical Pan and for Eastman 5369. Measurements involved a Kodak Photographic Step Wedge and a Kodak Color Densitometer Number 1.

Table 3. Equidensity Values for Technical Pan and Eastman 5369

 

Equidensity Parameter

Film

Gamma Pos.

Gamma Neg.

Log Exp. Range

Dmin

Dmax Pos.

Dmax Neg.

Technical Pan

1.8

2.0

1.38

1.3

2.8

3.0

Eastman 5369

3.7

1.3

1.41

1.0

2.7

2.4

The D log E equidensity curves for Technical Pan and for Eastman 5369 resemble a trough in cross section (Yurow). Complex curves of this type can be described with six parameters: gamma values of the positive and negative portions of the curve, maximum densities of the aforementioned two portions, minimum curve density (equidensity or depth) and log exposure range (width) of the curve (Lau and Krug). The last named can either be measured by the x-axis intercepts at a D value of 2.5, which correlates approximately to the visual limit to viewing shadow detail in a diapositive, or by a term involving the reciprocal of the square root of the product of the positive and negative gamma values.

Balboa Park, by Harvey W. Yurow

Eastman 5369 Developed
w/ Equidensity Developer

While the two equidensity gamma values for Technical Pan are similar in value, those for Eastman 5369 are quite divergent. This behavior is indicated by the unusually high gamma (3.7) of the positive image for the Eastman film and the relatively low gamma (1.3) of the negative image. The pictorial result here is that the positive image manifests itself in a more substantial form, rather than the more ethereal one given by Technical Pan. This behavior may be connected with the  presumably smaller size for the former of its silver halide grains, as indicated by its higher resolving power. The effectiveness of either film rendition will obviously depend upon the nature of the subject matter photographed.

For the reversal diapositives, gamma values are essentially identical for both films (2.3) , while higher maximum density of Technical Pan (3.0) produces noticeably deeper blacks - but despite this, those for Eastman 5369 (2.5) are quite satisfactory.

Other film processing comparisons of interest include development to a negative, either high contrast, or to a more “normal “ gradation. With the latter, speed loss for Eastman 5369 would be such as to preclude hand-held exposures. As regards high contrast development as a negative, basic sunlit outdoor exposure for Eastman 5369 with a Wratten #25 filter, followed by development in D-97 for 6.0 minutes at 20 C was determined to be 1/60 f2.8, for a published gamma value of  3.6 (Kodak 1997). In this connection, one peculiarity worth noting for Eastman 5369 is the rapid attainment of maximum gamma with the recommended D-97 developer, whose formula approximates that of D-52. With a somewhat similar film, Eastman Fine Grain Release Positive Film 5302 and D-97, gamma is increased considerably more slowly (Kodak 1999). Here again, behavior may be related to the unusually small size of the silver bromide grains in the 5369 emulsion.

At this point, some discussion may be of interest regarding special processing of cinematographic positive films. Kodak (1936) mentioned that “It is well known, however, that the shape of the characteristic curve for positive film can be modified profoundly by the composition of the developer, and many laboratories use developers which produce curves quite different from those shown (by the manufacturer)”. In a similar vein, Feiner indicated that for Kodak 2360 film “special combinations of developers are used which allow a greater density range than provided for by the film specifications,” while Amy Vincent (Kodak 2000) in describing Eastman 5369, indicated that “it takes some tweaking in the lab processes”. These quotations would tend to indicate that development of Eastman 5369 film should provide for a considerable degree of experimentation by photographic investigators.

For those who care to experiment, the following information on equidensity development may be of interest (Yurow).

Equidensity Developer

Sodium sulfite anhydrous

18.0 g

2-Chlorhydroquinone 85%

5.0 g

Sodium metaborate tetrahydrate

40.0 g

Boric acid

2.5 g

1-Allyl-2-thiourea

0.75 g

Distilled water to make

1000 cc

Development time for the above formula, found suitable with several different high contrast black-and-white photographic emulsions, is of the order of 5 minutes at a temperature of 20 C, the latter  being held within fairly close limits. One source of chlorohydroquinone and allylthiourea is Antec, Inc., of Louisville, KY (info@kyantec.com).

Finally, it should be noted that while Technical Pan was discontinued because of a serious tapering off of demand, Eastman 5369 is currently used in large amounts by the motion picture industry, and should be available for a considerable time to come.

The majority of references listed below are available as Internet downloads.

 

REFERENCES

Anon, “Eastman High Contrast Panchromatic Film”, Journal of the SMPTE, 82, 828 (1973).
Anon, Reversal Formulas, March 10, 2003.
APUG, How Was Tech Pan Emulsion Different?
Beyer, W. “Traveling Matte Photography and the Blue-Screen Process”, Journal of the SMPTE
        74, 217-239 (1965).
Brain, M., How Blue Screens Work.
www.cinematography.com, Search term “5369”.
Erland, J. Matte Process for Composite Photography, US Patent 6,211,941, April 3, 2001.
Everhart, E., “Are Microfilms Useful in Astrophotography?”, AAAS Photo-Bulletin,
        No. 30, 12-15 (1982). adsabs.harvard.edu/fall/1982AASPB..30...12E
Feiner, P.J., Bushman, C.B., Houston, J.D., Leconte, D.P., Method for Conversion and
        Reproduction of Film Images Through a Digital Process, US Patent Application Publication
        2006/0023275 A1, Feb.2, 2006.
Kodak, D-30, Kodak Imagelink Microfilms, Rochester, New York September 2009.
Kodak, Kodak Motion Picture Products Price Catalog, 2009.
Kodak, “Amy Vincent Discusses Her Vision for the Caveman's Valentine”, In Camera, October 2000.
Kodak, H-1-5302, Eastman Fine Grain Release Positive Film 5302/7302, Rochester, New York 1999.
Kodak, H-1-5369, Eastman High Contrast Panchromatic Film 5369, 2369, 3369, Rochester,
        New York 1997.
Kodak, P-255, Kodak Professional Technical Pan Film, Rochester, New York, 1977, 2003.
Kodak, AF-13, Kodak Black-and-White Film in Rolls, Rochester, New York, November 1967.
Kodak, P-9, Kodak Photographic Films and Plates for Scientific and Technical Use,
        Rochester, New York January 1960.
Kodak, Copying, 4th Edition, Rochester, New York October 1952.
Kodak, Motion Picture Laboratory Practice, pp 52-59, Rochester, New York 1936.
Lau, E. and Krug, W., Equidensitometry, Focal, London 1968.
The Man Who Wasn't There”, review by Roger Ebert.
Trumbull, R., Erland, J., Fog, S.  and Burke, P., Flux Projection for Use with Composite Photography,
        US Patent 4,629,298,  December 16, 1986.         
Yurow, H.W., Photographic Developer for Direct Production of Equidensity Images on a High
        Contrast Film, US Patent 6,083,671, July 4, 2000
.

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