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 Arista.edu 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.
Last night while the overhead light was on in the garage/darkroom I let a piece of Arista.edu 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.
