In an ongoing effort to improve the quality of my gum prints I’ve spent the better part of last year adjusting the curve that I use to make the negatives. Below is the curve used for my last show “Naiads” in 2010 next to the new “2011 curve” I’ve been working on (shown in red).
Keeping the lower end of the curve (representing the shadows) the same, I “pulled” up on the upper portion (representing the highlights) in order to get better separation in the lighter tonal values.
The results were successful in achieving the desired tonal definition in the highlights and this “2011 curve” what I gave my students to use to make their gum prints last fall semester.
Afterwards, I wondered if similar results would occur if I “pulled down” on the curve for better tonal separation in the lower values to produce more “sculptural” shadows. If it is true, then the question is how much do I “pull down” on the curve?First, I started by keeping the D-max the same output level as with the 2011 curve (22% black) and lowered the next three points (shown in orange), which would allow for greater density in the darker values of the print.
22% Curve
Input Output
0————-22
16————44
30————59
44————69
58————76
72————80
86————83
100———–85
I also tried keeping pulling down on the D-max to an output of 19% black while slightly adjusting the other three points.
19% Curve
Input Output
0————-19
16————44
30————59
44————69
58————76
72————80
86————83
100———–85
I achieved more density in the shadows but at the risk of losing some detail (both color and tone) as shown in the print comparison below (“2011 curve” on the left and the “19 % pulled down curve” on the right). The shadows appear too abruptly with the “19 % pulled down curve” and doesn’t possess the subtle nuance of transitional values of the “2011 curve”.
In an attempt to find an acceptable middle ground between the two above prints, I will next try “pulling up” the curve so that there isn’t such a dip in the first 4 points.
