E4 went through C-22 just fine! No prehardener was needed for E3 or E4 in C-22, and you usually gained a stop in speed. HS Ektachrome at 160 became a fine 400 film in C-22. The front cover of Life taken of Alan Sheppard as he left his Mercury capsule was shot and processed that way. It was then heavily color and contrast masked to fix it up. The original was a bit yellow in the toe.