Quote Originally Posted by philldresser

Excel formula =POWER(A2,1.49) where A2 is the time in secs

That is close to the SQRT of 2 (1.41 et c.). I have been using that (SQRT 2) as a guidline for years. I discovered the same factor is useful in determining zone development times. Maybe a paper is in order? Ever notice the frequency of occurrence of this factor in photography and optics?