U of S | Mailing List Archive | alt-photo-process-l | Re: digital negative possibilities for gum

Re: digital negative possibilities for gum

No argument there, Sam, but we were talking (I thought) about a straight-across comparison between an inkjet negative from a 360 ppi file, and the same file turned into a 360 ppi bitmap. Of course higher resolution bitmaps will be less gritty; I would have assumed that would go without saying.

On Oct 20, 2006, at 5:44 AM, stwang@bellsouth.net wrote:

Wait! You mean to tell me that Lenswork magazine reproductions look rough and gritty? They are printed from very high resolution diffusion dither negatives.

There are 2 apects of bitmap negatives that no one mentioned: resolution and density. At higher resolution, say 400LPI (not dpi), you can't see the dots unless through a strong magnifier. Look at your inkjet prints and try to see the dots. The other is density. Service bureau negatives are extremely high contrast, just like in Photoshop and properly processed Koalith, perfectly black, but very small, dots on clear film. Whereas inkjet negatives, whether bitmapped or not, typically are formed by grey or colored dots that transmit some light.

And each of these affect how the resulting gum print would look like. And each will need a different curve and a different way of printing.

Sam Wang

From: Camden Hardy <camden@hardyphotography.net>
Date: 2006/10/20 Fri AM 12:26:09 EDT
To: alt-photo-process-l@usask.ca
Subject: Re: digital negative possibilities for gum

I am not sure what you are asking when you said "why?" below.

Some people prefer the rough, gritty look.  I know I do sometimes...

Camden Hardy