Dmax on Arista/Foma paper

Discussion in 'B&W: Film, Paper, Chemistry' started by Paul Verizzo, Apr 20, 2008.

  1. Paul Verizzo

    Paul Verizzo Member

    Jan 20, 2008
    Sarasota, FL
    I don't own a reflective densitometer, OK, nor a transmisstion one. But I own a light meter and a CdS cell which I've calibrated to my Stouffer T2115 step tablet.

    Last night while the overhead light was on in the garage/darkroom I let a piece of Ultra (Foma Variant III MG) semi-matte paper get exposed. After "awhile" I put it in the developer, ID-62 1:1, the light still on, for some more "while," at least several minutes. Fixed and dried.

    Today, in bright Florida sunlight registering EV 16.25-ish @ ASA, oops, ISO 100, I measured the transmission of the paper by both the light meter and the CdS cell. I figure that the density of the developed silver as measured would not be effected by surface reflection. I used the base unexposed and fixed for "base plus fog" and the highly exposed and developed sample.

    I was very careful about light leakage around the samples as held tightly against the light meter opening and the CdS cell. It took a few runs, but I finally got stable results ...... and in agreement!

    The bottom line, a Dmax of 2.5, give or take some error.

    I know, I know, the surface matters in the densitometry and the subjective look. Besides my lack of equipment mentioned above, I was really interested in the emulsion Dmax, not surface effects. You can't get a good reflective Dmax if it isn't there to start with.

    I look forward to trying this with "silver rich" Varycon in the near future. And old Kodak Polycontrast.