Fw,(posted 8971 days ago)This can be a complex and involved topic, probably a bit too involved to discuss it fully in such a limited format as this.
The previous poster's articles should answer a lot of your questions. Just a few, brief personal observations.
For very high contrast scenes, I have used highly dilute HC110 with 4x5 Tri-X, as a "compensating" developer, with very good success, as per Adams' suggestions from his book "The Negative". I also have used the water bath technique with highly dilute HC110 in the past, but without as much success. Naturally, extremely long development times are the rule.
There was also a good article in last month's issue of "View Camera Magazine" by a photographer (I cannot recall his name, sorry!) using Rodinal in very high dilutions (1:150, or so). He discussed his technique using highly dilute Rodinal with modern films, in lieu of the traditional zone system controls (N-1, N-2, etc.) with very high contrast scenes. He made some very good points, which I intend to try out in the future.
I also strongly suggest looking at "The Film Developing Cookbook", by Stephen Anchell and Bill Troop. This book has lots of very good, detailed info and tips on the whole subject, fully discussing the pros and cons of highly dilute developers (increased grain, etc) The book also provides extensive development charts for all films and developer/dilution combinations. It's really a must-read basic text for all film development questions.
Just a brief quote from the Cookbook: "Compensation and Gradation....Virtually all high definition developers are compensating developers which produce a longer tonal scale due to reduced highlight contrast. In sensitometric terms, the shoulder is reached sooner, and its slope is more gentle than with normal development. Compensating developers are especially useful for high contrast scenes." I could go on quoting passages from this book, but.......
Hope this helps. Good luck, Sergio.