Hi Chris,
Be happy to comment.
Alternative process printers began working with digital negatives in the early to mid 1990s. One of the pioneers in this was Dan Burkholder, who wrote an early book on the subject, Making Digital Negatives for Contact Printing. Later Mark Nelson introduced his PDN method on a CD, called Precision Digital Negatives. His method allowed for some refinements for process and printer not available with Dan's methods. More recently Ron Reeder wrote a book on making digital negatives and promotes the use of QTR to control ink deposits. There is also a very nice program called ChartThrob available for free that works great.
Basically, what we do is prepare our digital file in Photoshop, as one does for making a digital print on an inkjet printer. However, before sending the file to the printer we lay down a process curve, that attempts to calibrate input values of Photoshop to output values of the process, be it silver, pt/pd or carbon. The digital negative itself is printed on a OHP (overheard transparency material) that accepts the ink (or pigmented ink) of the printer being used.
Most people use Epson printers for this (Epson 2200, 2400, 3800, 4800,etc.) but practice shows that some of the new HP and Canon printers are also capable of making good digital negatives.
You can find a lot more information about this at the hybrid forum,
http://www.hybridphoto.com/forums/
Sandy King
Bookmarks