I've used HC-110 with Tri-X sheet film at up to 1:30 (from stock not concentrate) such as Adams mentions. You will have to give an extra 1/2 stop of exposure or so or you will end up with pretty thin negatives. As Pete says a Jobo defeats the purpose of using high dilutions for compensating effects. For extreme highlights I think I would rather try a divided developer, I didn't really see any great difference using HC-110 at such a high dilution over a more moderate dilution with shorter developing times, but your results may vary!(posted 8282 days ago)