I use a Stouffer 4x5 inch 31 step transmission wedge in the following way.

First, I place the wedge in a negative carrier and backlight it with evenly diffused light, with all stray light around it blocked off to prevent excessive flare. Then I photograph the step wedge with the film and camera I'm testing, using only the central portion of the negative, regardless of format. Since the Stouffer wedges are 10 stops, I meter the backlight without the wedge in place, and then set the exposure at 5 stops greater exposure than the backlight. This places the middle step(s) of the Stouffer wedge at medium gray, or what a Zone System user would call Zone V. It also gives a scale that reaches +/- 5 stops from middle gray, enough to cover 99% of shooting situations. I bracket if I feel I need more than the 10 stop range to test for unknown film speed or other factors.

I develop the film and then place it in the enlarger I use for printing. I project the negative of the step wedge onto the baseboard and focus, then read the steps with a Darkroom Automation Enlarging Meter. This gives me relative readings in stops (to 0.01 stop resolution) for each wedge, which is easily converted in a spreadsheet to optical density by multiplying by 0.30. The reason I use only the central 1/3 or so of the negative is to minimize light falloff in the enlarger. With the spreadsheet it's very easy to calculate fb+f and find where the Zone I density falls. The spreadsheet can draw a graph and calculate your choice of contrast indicators.

As Ralph indicates, this is a real end-to-end test of the process. It's also a very quick and easy way to add a one frame process control strip to any single sheet or single frame of roll film.

Lee