Re: For those who are interested in making digital negatives using pigmented inksets

Jeffrey,

I took a look at your website and the experiment on paper grain and resolving
ability. I am wondering what printer you used to print the line pairs.
The prints of 600 ppi, 300 ppi, & 150 ppi look pretty much like what I would
expect as a result of the dot gain and limit of most printers to print well
beyond 360 ppi, or 480 ppi at the most. You get the best line separation with
vertical lines and less so with horizontal lines. Your test would be
interesting with vertical and horizontal lines from an imagesetter, which could easily
render the lines at the resolution you were testing.

I do agree though with you and Sandy that paper surface or grain can easily
overpower the resolution of a negative.

I was looking for information on what the human eye can resolve and so far
have come up with something in the neighborhood of 300 ppi—if anyone has
information on that, plus the number of gray levels that the human eye can
distinguish (I've seen everything from 200 to 1000) I would appreciate the site.

Thanks,
Mark Nelson

In a message dated 1/1/04 10:50:59 AM, jeffrey.d.mathias@att.net writes:

> s, I am referring to the resolution limit due to the paper surface. In
> > other words, no mater how sharp your negative may be there is a limited
> > amount of resolution that a watercolor or drawing paper can convey.
>
> The following link shows a simple way to measure the resolution of the
> paper.  In this case, the paper is Crane's Cover-90.  It seems to be
> able to resolve somewhere between 300 and 600 lpi. A 600 ppi negative
> should have enough resolution so as not to be detectable when using this
> paper.  I would not recommend 360 ppi as this would not yet be beyond
> the resolving capability of this paper.
>
> http://home.att.net/~jeffrey.d.mathias/guide/digital/appendicies.htm#resoluti
> on
>
Received on Thu Jan 1 20:30:25 2004