I am new to LF but not new to film, but I still have questions about developing. With 35 mm developing with an in camera spot meter, I have become good and repeatable with my small tank development, but I never really went beyond developing film based on the normal spec sheet times/temp. 36 frames had way to many different frames with varying contrast.
I expected to use LF sheets to learn about deviating from the spec so I can control contrast, but my progress at sheets even from the spec sheet (patterson tank or tray) has been problematic - sometimes perfectly exposed and more often underexposed/underdeveloped.
But before I continue to try to debug my process, I think I first need to get my head around a few concepts. Can someone help me understand what the differences conceptually between the following and how they relate as well.
1) Personal Exposure index
2) Pushing and pulling from normal development
3) Using film a particular film at a non-specified ISO like "TMAX 400 exposed at 200"
4) Setting a given meter reading to be on Zone III instead of V
All of these manifest themselves in one way or another to modifying the values from my spot meter.
I believe my goal is to find my 1) so I know that I can correctly expose for my shadows by 4) so I can control the contrast with 2), but I don't know why anyone would do 3)?
What don't I understand?