Tim, I think there is a simpler way. It produces better results than any
inkjet negative. Ralph agrees.
You simply photograph a 12x16 inkjet print and print the negative :)
1) If the image has a resolution 600dpi any competent inkjet printer will
give you about 9 lp/mm on paper.
2) A 4x5 negative copy, taken with a standard lens and printed at 12x16
still has a resolution of 7lp/mm on paper (Nikon 150, f11, TriX)
Now here is the clever bit. Use a smooth matt paper. It avoids all the
issues of lighting reflections and so on. In fact, diffuse lighting works
better with matt originals.
You also need to adjust the print tonality for the negative / photo paper
process. I did this very simply:
Make a simple stepwedge in 5%K increments and print it on an inkjet printer,
using whatever method you use to produce accurate prints.
Stick the print to the wall and take an incident light reading. Use the
film's ISO value and add a stop of exposure for good measure. Copy the
picture, using medium or large format (I think 35mm is chancing it) and
develop it at N+1. This gives a negative which will print full range at
grade 2. Make a print of the stepwedge, adjusting contrast and exposure to
get a full range of tones. Compare this print with the inkjet print and make
a conversion table for equal print densities. (You can do this more
accurately with a densitometer). This table becomes a saved photoshop curve.
When you want to make a negative, you first make a proof print on the inkjet
printer and satisfy yourself it is OK, then print it again at 12x16 or
similar, after applying the Photoshop curve. The print will look a little
weird, but when you photograph it and reprint it, will resemble the proof
print, providing you stick to the same exposure, development and printing
conditions.
If the print head is aligned properly (and there are no striations in the
inkjet print), you will only see film grain in the final print, with smooth
gradation in highlight and shadow tones. I had success first time with this
approach and want to sell my shares in Pictorico.
Chris Woodhouse
