Quote Originally Posted by Silverpixels5
Sandy:

I metered for zone 1 and made an exposure, as well as exposures 1.5 stops above and below this reading in 0.5 stop increments. After processing, I metered each exposure with a one degree spot meter. The zone 1 exposure that gave me about 0.09 above base+fog corresponded to a film speed of 100. This was just one test so I havn't tried to see if it was repeatable yet. I also don't know how much density the stain added, so again my results are suspect. Is my use of the 2:2:100 dilution the correct one for printing on azo, or should I be using the 1:1:100 dilution? Thanks for any help you can offer.
Your method is a valid way to determine your personal effective film speed because it takes into consideration your shutter and lens aperture, meter and metering system, and method development. It is not a good way, however, to provide relative data useful to other users because in practice the various parts of your system could lead to exposure errors of up to one stop and even greater. In my own work I make tests for effective film speed with a carefully calibrated system that uses a light integrator to give an accuracy of exposure of 1/100 of a second. So when I compare the relative speeds of different film/developer combinations I can be sure that these comparisons are valid.