The Photographer's Formulary 09-0335 Step Wedge (4x5") is an asset when trying to calculate exposure. The steps, corresponding to about a 1/2 stop, give you a complete look at what exposure would be at any given f-stop. This item will be especially useful to anyone involved in alternative processes.
Displays film densities from .05 to 3.00 units in steps of approximately .15 (1/2 stop)
UPC: 675152903358