Enlarged Negatives for Platinum Printing
An Economical Approach

By Michael J. Kravit, AIA
Ó Michael J. Kravit, AIA, All Rights Reserved

Searching for an economical methodology to create enlarged duplicate negatives had become somewhat of a quest for me. Working with commercial and professional orthochromatic copy films can be a very expensive proposition. Especially when you consider that on average I was making 4-6 diapositives, employing various amounts of dodging and burning before I even came close to the pre-visualized image that the photographer in me yearned for. I began to investigate the use of low contrast print and film developers and high contrast lithograph films. The results were less than stellar. I continued using commercial ortho films for both the inter-positive and the duplicate negative, but varied the developer concentration to arrive at the desired contrast and density range. At almost two dollars per sheet my trash can began to hold more than my savings account!

Finally, one afternoon while surfing the Internet I came across an outline by Stuart Melvin of Santa Fe, New Mexico that described a method using inexpensive high resolution/high contrast lithography film and PMK Pyro! Could this be the magic pill? I could hardly wait. I got on the phone and ordered a box of Arista Premium Halftone Supreme. Freestyle Sales Company, the distributor of this film describes APHS as a “film designed for halftone reproduction, this film provides the ultimate in true lith resolution. Excellent tonal quality and latitude. Produces beautiful tonal renditions when processed in continuous tone developers.” Now I was really getting excited, could it be that this film would render my prints with smooth continuous tones, sharp crisp images with a glow that accentuate the platinum print’s almost three dimensional quality, all at an economical price? This must be a dream, it just could not be. I had nothing to loose, I was already using PMK Pyro for processing sheet and roll film with excellent results so I felt that this would be a natural transition.

The Arista Halftone Supreme arrived at my office a few days later. A box of 100 sheets cost me $42.95! Yes, that equates to only $0.43 / sheet. The math was simple, 5-6 sheets, dodging and burning, fine tuning exposure, and I have only spent two to three dollars! I ran through the process in my mind, working out every detail and contingency I could think of. I read and re-read Melvin’s outline and detailed how I would adapt it to the developers and film that I use on a regular basis. Everything was set; I began testing the materials and worked out the process. With a bit of time and testing the process began to take shape. The duplicate negatives I made using the APHS had sufficient contrast that I could tailor the density range to print without Potassium Chloride or other contrast agents (restrainer). This meant that I could standardize my developer on PMK Pyro and not bother keeping a series of high contrast developers on hand. Previously, to obtain the proper density range to print in palladium without using contrast agents, I would have to build density with developers like D-19, D-11, or D-8. Other developers such as HC-110 would produce chemical fog long before I obtained the contrast and density range I needed. It has now been a year since I switched to the Arista Premium Halftone Supreme and PMK Pyro process. The following outlines the procedure that I use to create enlarged duplicate negatives.

I setup my images in a traditional manner utilizing the zone system. Light meter readings are taken for the darkest shadow areas that I want to hold detail and placed on the appropriate zone. The brightest area in the scene is measure to determine the brightness range of the scene allowing me to determine the proper development time for the negative. Negatives are processed in PMK Pyro, Xtol or Ilfotech DDX depending on how the wind is blowing and my mood. All sheet film is processed in a Jobo CPP-2 utilizing the Expert Drums. I find that streaking of my negatives is non-existent when using the Expert Drums.

After processing the film, each negative is contact printed and evaluated for exposure, composition and it’s potential as a platinum/palladium image. Not many of my images make the cut at this stage, but every once in a while the “wow” factor comes into play and I begin the enlarged negative process. For the most part the majority of my negatives be it medium format or 4x5, are enlarged to 8”x10”, or 10”x12” in size. To make the diapositive the medium or large format negative is placed in the enlarger and the image composed on the baseboard with a sheet of white paper corresponding to the desired final negative size in place of the film. The negative is then removed and the enlarger is adjusted to produce 1-foot candle of light on the baseboard. If necessary a neutral density filter is installed to reduce light output. On my Durst, I find that the majority of the time, I set the lens aperture to f/11 and my exposure times are in the 4-6 second range. A sheet of Agfa Gevatone N31p or Ilford Commercial Ortho film is placed on the baseboard and covered with a sheet of 1/8” clear plate glass. The image is projected onto the film just as a standard test strip is made; with exposures of 1⁄2 second each. The film is processed in a Jobo Expert Drum with PMK Pyro, utilizing standard development techniques and a 1:2:100 dilution. When dry, the film is read on an X-Rite 811 color densitometer through the blue filter channel. I then look for the strip that has the brightest non-specular highlights that measure .35 density units. Using PMK Pyro the majority of my diapositives seem to process in approximately 8 minutes. I then check the shadows for a density of 1.20-1.25 and a density range of .85 to .95 density units. During this process, local controls such as dodging and burning and are employed to obtain the desired effect. Once my diapositive looks the way I want it I begin to make the second generation or enlarged negative.

The enlarger is set to a height of 20”. This works well for 8”x10” to 10”x12” negatives. The light is masked using the blades on my negative carrier and I adjust the aperture to obtain 1-foot candle of light on the baseboard. The enlarged negative is made by contact printing the diapositive onto the Arista Premium Halftone Supreme. A contact sandwich is made with the diapositive that was previously made and a sheet of APHS. The two sheets of film are covered with a sheet of 1/8” clear plate glass. I have found that the exposure time for the majority of my positives at this stage runs approximately 15 seconds with the aperture set to f/16. The exposure is made and the APHS is now placed in the Jobo Expert Drum or a tray for processing. The negative film is processed utilizing a 1 minute presoak in either water or sodium metaborate. I prefer the sodium metaborate solution. I mix up 1 liter of PMK Pyro at a ratio of 1:1:100. It seems that by reducing the quantity of the part B developer the high contrast of the Arista Premium Halftone Supreme is reduced and the result is a smooth continuous tone image. The negative is processed for approximately 10-16 minutes. It is important to note that when using the longer processing times there is a significantly lower amount of chemical fog with PMK Pyro than with other developers that I have used. The majority of my negatives are processed for 10-12 minutes. After the required processing time, the negative is rinsed for 1 minute and the rinse water is changed twice. No acidic stop bath is used with APHS as I have found that it produces pinholes in the film. The film is fixed using a non-hardening fixer for 2-3 minutes and then transferred directly from the fixer to an after bath of sodium metaborate for two minutes. The negative is washed for twenty minutes, placed in a dilute wetting agent and allowed to dry.

The Arista Premium Halftone Supreme polyester base is significantly thinner than standard orthochromatic films. This means that the film dries very quickly but it also means that one must exercise a bit of care in the handling of the negative, as it will crease fairly easily. My final negative is measured on the densitometer and should show a highlight density of approximately 0.5 density units and a highlight density of 2.25 to 2.60 with the resulting density range of 1.75 to 2.10. This range assures that the image can be printed with 100% palladium without adding contrast agents. The resulting image exhibits a three-dimensional quality and a glow that I find can only be achieved through the platinum/palladium printing process.

The following is a brief synopsis of the process;

I. The Diapositive:
The diapositive should have a 3-4-stop range between the shadows and the highlights.
Density Values: (Values are above filmbase+fog)
Highlight Density - .35
Shadow Density – 1.20 – 1.25
Density Range (DR) = .85 to .95
At this point use the same technique as in making a print – Expose for the Highlights and develop for the shadows.

Processing the Diapositive:
Film – Agfa Gevatone N31-P or Ilford Ortho Plus
Pre-soak, 1 minute @ 68F in sodium metaborate

Developer – PMK Pyro, 1:2:100 dilutions. Time 6-10 minutes.

Stop Bath – Fresh water (No acidic stop bath)

Fix – Use a non-hardening, non-acidic fixer 2-3 minutes.

Wash – Time, 20 minutes at 75F

II. The Second Generation Negative or Enlarged Negative:
The second generation negative should have good detail in the shadows, well-separated mid-tone values and highlights that are dense but not so dense that you can’t read magazine print through them.
Density values: (Values are above filmbase+fog.)
Highlight Density – 2.25 – 2.60
Shadow Density - .50
Density Range – 1.75 – 2.10
At this point use the same technique as making an in the camera negative – Expose for the Shadows and Develop for the Highlights.

Processing the Enlarged Negative:
Film – Arista Premium Halftone Supreme
Pre-soak, 1 minute @ 68F in sodium metaborate

Developer – PMK Pyro, 1:1:100 dilutions. Time 10-16 minutes.

Stop Bath – Fresh water (No acidic stop bath)

Fix – Use a non-hardening, non-acidic fixer 2-3 minutes.

Wash – Time, 20 minutes at 75F

Note: As with traditional negatives processed in traditional non-staining developers I have found that if the final negative has the correct shadow density but lacks highlight density, you can increase the highlight density by approximately one stop with selenium intensification. Some stain may be lost to the selenium, but soaking the negative in a Pyro after bath or sodium metaborate tends to intensify the stain.