This really just won't work for split developing, as you found out. Dektol 1+9 is just a slow working higher-contrast developer, not really a low-contrast developer. If you want to experiment with split developing (a technique I still use a lot on graded papers) get yourself some Selectol Soft or mix some Ansco 120 or the like for the low-contrast component. The Beer's formula that AA used works well too, but I tend to just vary times in the low-contrast and high-contrast developer to achieve the desired result (e.g. 1'30" in Selectol Soft, 1' Dektol).
Originally Posted by akshaydhavle
I can't explain the difference in smoothness of tones you observed. It might be interesting to do some experiments along this line... when I get back to my darkroom this next summer.