..............has anyone ever used it? I finished tests with 4x5 TXP in HC-110 (1:63) at 68 deg F. I don't like the results, not attributing anything to the spreadsheet, but something I did I'm sure, but not sure what that is. I did not use a 6th sheet for film speed as I'm not sure how the actual film speed test is recommended by Ralph, I haven't got his book yet. I input a speed consistent with his statistical typical speed of 2/3 less box speed. The spread between the 4 min avg gradient and the 16 min avg gradient seems quite narrow to me, resulting in such a narrow range of development times from just below "N" to just below +2. This, I certainly did not expect as I was hoping for clear +2 to -2 dev times. I developed in the Combi-Plan tank, using inversion agitation cycle of 4/10/1--------4 inversions in 10 sec every 1 minute, there was no temperature drift, processing is very consistent. In the .xls attachments (hope you can view them) are the TXP test that I finished recently using the 4, 5.5, 8,11, and 16 min times and a TMX (x-tol 1+1) test I did last year, but before having this spreadsheet, the times are my own determined from testing as described here, I simply input the densities into the spreadsheet from those development times. The X-Tol results are much more normal to me, a difference obviously being it was with a 100 ISO film versus an ISO 320 film with TXP. So, this test with TXP seems strange to me, and I exposed the step tablet the same in both tests i.e., a Zone X exposure. But, one difference may be that I used a middle gray test target in the X-Tol test and a white test target in the TXP test, I don't see why that should matter. The TXP test results simply do not look right. I welcome any thoughts.............especially Ralph's. Thanks.