Pyro Colorized Digital Negatives for the Epson 1280

Keith Schreiber

Here is a method of making digitally enlarged negatives for contact-printing in Palladium using the Epson Stylus Photo 1280 with standard Epson inks printed on Pictorico OHP Transparency Film. This is a spectral density method that evolved from working with Dan Burkholder's methods but encountering some problems that I hoped could be improved upon. I was getting a nice full tonal scale using Dan's "rubylith" color table method (0-55-55-0), but there was noticeable posterization throughout. I happened at the same time to be printing 8x10 negatives that had been developed in PMK Pyro and wondered what would happen if I could duplicate the amber-green stain of Pyro in an inkjet negative. I guess I was lucky that day because my first attempt eliminated most of the posterization problem. Tweaking the curve (an ongoing process) linearized the negative to the tonal response of my materials. This method is optimized for an exposure scale of 1.9 as determined with a Stouffer step-tablet. My standard mix for an 8x10" print is 1ml Ferric Oxalate + 1ml Palladium + 1 drop of 2.5% "Na2" Platinum.

Begin with your fully edited ready-to-print image file in grayscale mode. In my opinion it is best to start with 16-bit grayscale with Dmax and Dmin values set to a few points inside the extremes (e.g. Dmax 96%, Dmin 4%) to avoid any possibility of clipping. RGB images can be used but must be converted to grayscale prior to applying these steps. Steps 1 through 4 can be recorded as an action in Photoshop. Here is a step-by-step outline of the process as done on a PC with Photoshop 7.

  1. Be sure that your Color Setting (Edit>Color Settings) are set as shown:

  1. Flatten any layers (if necessary) and convert image to 8-bit grayscale.

  1. Apply tone correction curve. (This will be specific to whatever printing process you are using and will probably need to be fine-tuned to take into account personal variables. My curve is designed for printing palladium with an addition of 1 drop of 2.5% Na2 Platinum per 2ml of solution which is just enough to assure unfogged highlights with a negligible increase in contrast.

    Better yet, if you can stay in 16-bit grayscale for all of your editing, apply the curve before switching to 8-bit mode. Photoshop CS allows the use of 16-bit files for most functions, but not for indexed color mode.

  1. Convert Mode to Indexed Color

  2. Apply color table as follows:

  3. You are now ready to print. Go to Print with Preview to set up your printing parameters. Click Page Setup, then Printer, then select the printer you will be using and click Properties.

    • On the Paper Tab set paper size and orientation as desired.

    • On the Main Tab use the following settings:

      • Media Type: Photo Quality Glossy Film

      • Ink: Color

      • Mode: Custom > Advanced

        • Print Quality: SuperPhoto - 2880 dpi

        • Microweave (grayed-out, checked)

        • High-Speed (grayed-out, unchecked)

        • Flip horizontal: checked  (so that neg will print emulsion down)

        • Finest Detail (grayed-out)

        • Edge Smoothing: unchecked

        • Color Management: No Color Adjustment

      • *You may want to save these settings with a name such as "Inkjet Neg" so that you can then simply select it from the list of custom settings.

    • Click OK 3 times to get back to the Print dialog. Check Show More Options.

    • Under Color Management apply the following settings:

    • Source Space: Document (Untagged RGB)

    • Print Space

    • Profile: Same As Source

    • You are now ready to send it to the printer. I have found that a 13x19 sheet using most of the printable area takes about 50 minutes to print at these settings. If you this is too slow for you, change the Print Quality setting to 1440 dpi to cut the time in half. For many images the difference will be insignificant.

At the time I started working on this project I was using a laptop PC maxed out at 512Mb RAM. That is the machine that my original research was done on and it was fine with smaller files but choked on 16-bit grayscale files when converted to RGB for making colorized negatives. So last fall when the G5 Macs came out I picked up a G4 for a bargain and that was when the problems began. I don't mean to blame the Mac, but rather to say that changing platforms revealed some intricacies that I must have originally skated over by dumb luck.

Photoshop color settings, i.e. RGB and Grayscale working spaces, are critical. Not so much that one space or set of spaces is inherently better than another, but that if you change it will throw everything off. When I began working with this stuff following Dan's instructions I loaded his color setting file, which uses ColorMatch RGB and Gray Gamma 1.8. These are not my normal color settings for print purposes (I normally use Adobe RGB and Gray Gamma 2.2 on the PC), but since they are the settings I used when experimenting and tweaking my curve and color table, if I forget to switch to them when making negatives it doesn't work. On the Mac, I have things calibrated to my normal print settings (Adobe RGB and Gray Gamma 1.8) so that I don't have to worry about forgetting to switch. Eventually I'll do the same for the PC.

Another potential issue is that my negatives always printed with a lot more green than the screen image, which is more amber. I recently figured this out with help from a friend who suggested using a different print space profile on the Mac. My PC only had one profile for the 1280, though I also just discovered that this isn't really true either - Epson has put them in with the PIM option for the PC, which I had not installed, rather than with the regular driver as they are on the Mac. So now I know how to get the color of the inkjet negative to match the screen, but its printing characteristics are different so new curves and settings will now have to be worked out. I use the Photo Quality Glossy Film (PQGF) media type setting. If I set the print space profile to 1280 (Standard) I get a green negative which prints beautifully with the right settings and curve. If I set it to 1280 PQGF I get an amber negative which does closely match the screen but the details still need work.

© 2004 Keith Schreiber