Quote Originally Posted by Francesco
I am interested in AZO contact printing of 12x20 negatives. What are your experiences and which is easier, using digitally enlarged negatives (i.e. purchasing and using software, printers, pigments, etc. etc.) or simply buying a 12x20 camera and doing it the old fashioned way? Pros and cons of each.
Digital negatives have some clear advantages over original camera negatives. They can be adjusted in Photoshop to give exactly the tonal range desired and any corrections, burning and dodging that is needed can be done on screen so that in effect you have negative that will print perfectly every time. Another consideration is that since you are adjusting the on-screen image to give exactly what you want to see on the print exposure times and contrast will be virtually identical for every negative. Always scan at a minimum of 360dpi at the final print size. For example, if you plan to make a 15X21" digital negative from a 5X7, which amounts to a 3X enlargement of the original you should scan the original at a minimum of 1080dp. Also, to avoid posterization always scan in 16 bits and keep the file in 16 bits in Photoshop all the way to final output. Since many of the tools are not useful in 16 bit in older version of Photoshop you will need th latest version of Photoshop, known as Photoshop CS or Photoshop 8, to get maximum image quality as it pertains to tonality.

The question most people have is how digital negatives from inkjet printers compare to those from in-camera originals. The answer is very well indeed. In fact I would go so far as to say that in many ways the prints I make from digital negatives are better than the ones I make from in-camera originals. This is due to the fact that I am able to adjust the tonal values of the digital negative to exactly what I want and can also enhance the apparent sharpness of the negative with the unsharp mask option.

Opinions will vary on this but bear in mind that my views on the subject are based on extensive printing with several alternative processes using both large format and ULF negatives, including 12X20, as well as enlarged digital negatives. In my own work I find that 13X19 prints made from digital negatives of scanned 5X7 originals are of virtually identical quality to prints made from original in-camera negatives of 12X20 in size. Please note that my reference is carbon, kallitype and palladium prints on art papers where the texture of the paper is the limiting factor in sharpness, not the negative. What you find is that with digital negatives you are limited by both the paper surface and the resolution of Pictorico film to a maximum resolution of somewhere between 300-360lpi (or about 14lpm). Since a diamter of 1/100 of an inch, or about 5lpm, is generally accepted as the largest circle that will appear as a point at normal viewing distance the practical resolution of digital inkjet negatives is two to three times greater than necessary.

If the final print is to be made on AZO I am of the opinion that an original in-camera negative would give slightly superior results on the final print than an inkjet negative because with a very smooth paper the resolution of the negative is the controlling factor in apparent sharpness, not the paper.

The disadvantage of working with digial negatives is that you will have to spend a fair piece of change on computer equipment and software, plus a good scanner and printer. And if you don't already know how to work with Phtoshop there will be a learning curve involved. And finally, you will have to spend a great deal of time at the computer.

Sandy King